{ "data": { "a": { "slug": "cartesia-tts", "name": "Cartesia Sonic TTS API + MCP", "vendor": "Cartesia", "vendorUrl": "https://cartesia.ai", "kind": "model", "category": "text-to-speech", "summary": "Sonic text-to-speech, currently `sonic-3.6` in 44 languages, over `/tts/bytes`, `/tts/sse` and a WebSocket that takes streamed LLM text with contexts and word timestamps.", "url": "https://www.anchorterminal.com/tools/cartesia-tts", "markdownUrl": "https://www.anchorterminal.com/tools/cartesia-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/cartesia-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json", "dns": "cartesia-tts.grade.anchorterminal.com", "repo": "https://github.com/cartesia-ai/cartesia-python", "license": "Apache-2.0 (SDKs)", "transports": [ "http", "streamable-http", "stdio" ], "remoteUrl": "https://api.cartesia.ai", "packages": [ { "registry": "npm", "name": "@cartesia/cartesia-js", "main": true }, { "registry": "pypi", "name": "cartesia", "main": true }, { "registry": "pypi", "name": "cartesia-mcp", "main": true } ], "auth": "mixed", "authNotes": "`Authorization: Bearer` API key plus a required `Cartesia-Version` date header (currently `2026-08-14`). Browsers should use short-lived access tokens minted server-side. The hosted MCP at `https://mcp.cartesia.ai/mcp` signs in through the Playground and creates an MCP key. The local `cartesia-mcp` reads `CARTESIA_API_KEY`.", "pricing": "freemium", "pricingNotes": "TTS costs about 1 credit a character, charged only on successful requests. Free has 20,000 credits a month (about 27 minutes of Sonic 3.6), Pro $5 100,000, Startup $49 1.25M and Scale $299 8M. Overages, if enabled, cost $65 per 1M credits on Pro, $45 on Startup and $38 on Scale. Commercial use starts at Pro. Unused credits roll over up to 2 times the monthly amount (https://cartesia.ai/pricing).", "priceSummary": "$5 / mo", "where": "both", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing (checked 2026-09-30).", "endpoints": [] }, "toolCount": 19, "popularity": { "githubStars": 133, "npmWeekly": 166023, "pypiWeekly": 176771, "asOf": "2026-09-30" }, "docsUrl": "https://docs.cartesia.ai/build-with-cartesia/tts-models/latest", "llmsTxt": "https://docs.cartesia.ai/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.ssml", "speech.languages" ], "tags": [ "hosted", "freemium", "free-tier", "closed-source", "python", "typescript", "llms-txt", "mcp", "streaming", "enterprise" ], "lastRelease": "2026-10-30", "graded": true, "anchor": { "graded": true, "score": 61.9, "grade": "C", "agentReady": false, "rank": 582, "ranked": true, "rankOf": 1486, "categoryRank": 10, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 65, "maintenance": 84, "payments": 30, "reliability": 73, "schema": 86, "security": 47, "transparency": 73 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-02" }, "negative": -3, "negativeNotes": [ "September 2026 (dated by month only; the SDKs added `case_sensitive` on 2 September). Pronunciation dictionaries on Sonic 3.6 \"now ignore case by default\", so an existing entry starts matching other capitalisations and the audio for existing callers changes with no code change, and the API now rejects entries that collide under the new rule. No earlier notice was found in the changelog, so this run's same-day term applies (-3) (https://docs.cartesia.ai/changelog/2026)." ], "verdict": "The WebSocket accepts streamed LLM text with contexts, flushing and word timestamps, and dated Sonic snapshots never change. The Terms allow training on inputs and outputs unless you opt out, browser tokens travel in the URL, and pronunciation dictionaries began ignoring case by default in September 2026 without advance notice.", "bestFor": "Real-time voice agents that stream LLM output straight into speech and need stable, pinnable models.", "strengths": [ "WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps", "Dated model snapshots such as `sonic-3.6-2026-08-27` never change, and `Cartesia-Version` pins the API shape", "OpenAPI and AsyncAPI files per API version listed in llms.txt", "Short-lived access tokens with TTS, STT and agent grants for browser clients", "Deprecations dated in the changelog, with Sonic-2 and Sonic Turbo sunset after 20 October 2026 on about 83 days' notice" ], "weaknesses": [ "Pronunciation dictionaries on Sonic 3.6 began ignoring case by default in September 2026, with no earlier notice found", "TTS concurrency is 2 on Free, 3 on Pro, 5 on Startup and 15 on Scale", "The Terms allow training on inputs and outputs unless you opt out by form", "Zero data retention is Enterprise only", "No SLA, and no error responses documented for the TTS endpoints", "Browser clients pass the access token as a WebSocket query parameter" ], "agentNotes": [ "Send the `Cartesia-Version` header on every request.", "Pin a dated snapshot such as `sonic-3.6-2026-08-27` if output must not change.", "Use `sonic-3.6` or a dated `sonic-3.6-*` snapshot. `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` stopped working after 20 October 2026.", "Expect a 429 at the plan's concurrency limit and queue requests yourself.", "Mint a short-lived access token for browser clients instead of shipping the API key.", "Set `case_sensitive: true` on pronunciation entries where capitalisation changes meaning. Entries default to case-insensitive on Sonic 3.6." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 61.9 } ], "editorialScores": { "ergonomics": 65, "maintenance": 84, "payments": 30, "reliability": 73, "schema": 86, "security": 47, "transparency": 60 }, "provenanceScore": 86, "checked": { "categories": { "ergonomics": "2026-11-02", "maintenance": "2026-11-02", "payments": "2026-11-02", "reliability": "2026-11-02", "schema": "2026-11-02", "security": "2026-11-02", "transparency": "2026-11-02" }, "last": "2026-11-02", "lastMoved": "2026-11-02", "oldest": "2026-11-02", "stale": false, "staleAfterDays": 90 } }, "connect": { "http": "curl -X POST https://api.cartesia.ai/tts/bytes -H \"Authorization: Bearer $CARTESIA_API_KEY\" \\\n -H \"Cartesia-Version: 2026-08-14\" -H \"content-type: application/json\" -o speech.wav \\\n -d '{\"model_id\":\"sonic-3.6\",\"transcript\":\"Your table is booked for seven.\",\"voice\":{\"id\":\"47c38ca4-5f35-497b-b1a3-415245fb35e1\"},\"output_format\":{\"container\":\"wav\",\"encoding\":\"pcm_s16le\",\"sample_rate\":44100}}'", "claudeCode": "claude mcp add --transport http --scope user cartesia https://mcp.cartesia.ai/mcp", "config": { "mcpServers": { "cartesia": { "args": [ "cartesia-mcp" ], "command": "uvx", "env": { "CARTESIA_API_KEY": "${CARTESIA_API_KEY}" } } } } }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/cartesia-tts" }, "sameCompany": [ "cartesia-ink-stt", "cartesia-voice-cloning" ], "area": "voice", "unitPrices": [ { "item": "Sonic TTS overage on Pro", "unit": "1m-chars", "usd": 65, "note": "about 1 credit a character, $65 per 1M credits" }, { "item": "Sonic TTS overage on Startup", "unit": "1m-chars", "usd": 45 }, { "item": "Sonic TTS overage on Scale", "unit": "1m-chars", "usd": 38 }, { "item": "Pro plan", "unit": "month", "usd": 5, "note": "100,000 credits" }, { "item": "Startup plan", "unit": "month", "usd": 49, "note": "1.25M credits" }, { "item": "Scale plan", "unit": "month", "usd": 299, "note": "8M credits" } ], "provenance": { "legalEntity": "Cartesia AI, Inc.", "domain": "cartesia.ai", "domainRegistered": "2023-05-10", "endpointOnVendorDomain": true, "terms": "https://www.cartesia.ai/legal/terms", "privacy": "https://www.cartesia.ai/legal/privacy", "statusPage": "https://status.cartesia.ai", "changelog": "https://docs.cartesia.ai/changelog/2026", "securityTxt": "valid", "checked": "2026-11-02", "notes": [ "www.cartesia.ai/.well-known/security.txt answered on 2026-11-02 with a contact, a policy link to trust.cartesia.ai and Expires 2027-10-03.", "status.cartesia.ai is an incident.io page; its robots.txt answers an HTML 404 page (no rules)." ], "score": 86 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/cartesia-tts.json", "live": { "slug": "cartesia-tts", "probe": { "target": "https://api.cartesia.ai", "method": "get", "lastAt": "2026-11-07T18:20:16.163517449Z", "lastOk": true, "lastStatus": 200, "lastMs": 60, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 53, "p95ms24h": 131, "samples24h": 239, "samples30d": 7910, "days": [ { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 247 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 249 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 255 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 253 }, { "date": "2026-10-22", "probes": 253, "ok": 253 }, { "date": "2026-10-23", "probes": 248, "ok": 248 }, { "date": "2026-10-24", "probes": 251, "ok": 251 }, { "date": "2026-10-25", "probes": 250, "ok": 250 }, { "date": "2026-10-26", "probes": 252, "ok": 252 }, { "date": "2026-10-27", "probes": 249, "ok": 249 }, { "date": "2026-10-28", "probes": 251, "ok": 251 }, { "date": "2026-10-29", "probes": 249, "ok": 249 }, { "date": "2026-10-30", "probes": 248, "ok": 248 }, { "date": "2026-10-31", "probes": 251, "ok": 251 }, { "date": "2026-11-01", "probes": 249, "ok": 249 }, { "date": "2026-11-02", "probes": 250, "ok": 250 }, { "date": "2026-11-03", "probes": 248, "ok": 248 }, { "date": "2026-11-04", "probes": 246, "ok": 246 }, { "date": "2026-11-05", "probes": 185, "ok": 185 }, { "date": "2026-11-06", "probes": 241, "ok": 241 }, { "date": "2026-11-07", "probes": 187, "ok": 187 } ] }, "vendorStatus": { "page": "https://status.cartesia.ai", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-11-07T18:20:38.07161798Z" }, "versions": [ { "registry": "github", "name": "cartesia-ai/cartesia-python", "version": "v4.2.0", "released": "2026-09-02", "seenAt": "2026-11-06T23:13:26.405806168Z" }, { "registry": "npm", "name": "@cartesia/cartesia-js", "version": "4.2.0", "seenAt": "2026-11-06T23:13:24.187943574Z" }, { "registry": "pypi", "name": "cartesia", "version": "4.2.0", "released": "2026-09-02", "seenAt": "2026-11-06T23:13:24.399324036Z" }, { "registry": "pypi", "name": "cartesia-mcp", "version": "0.29.0", "released": "2026-11-05", "seenAt": "2026-11-06T23:13:24.506276643Z" } ], "githubStars": 139, "npmWeekly": 105860, "pypiWeekly": 241069, "securityTxt": { "url": "https://cartesia.ai/.well-known/security.txt", "state": "valid", "expires": "2027-10-03T00:00:00.000Z", "checkedAt": "2026-11-07T16:01:22.207018558Z" }, "llmsTxt": { "url": "https://docs.cartesia.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:31:50.167568829Z" }, "domain": { "domain": "cartesia.ai", "registered": "2023-05-10", "source": "https://rdap.identitydigital.services/rdap/domain/cartesia.ai", "checkedAt": "2026-11-01T14:10:04.149838535Z" }, "pages": [ { "url": "https://docs.cartesia.ai/changelog/2026", "kind": "changelog", "status": 200, "checkedAt": "2026-10-08T18:18:24.003636335Z", "changedAt": "2026-10-07T18:04:49.25388057Z", "fingerprint": "405fadad924b" }, { "url": "https://cartesia.ai/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-11-07T14:00:46.648388282Z", "changedAt": "2026-11-07T14:00:46.648388282Z", "fingerprint": "3a338414361a" }, { "url": "https://www.cartesia.ai/legal/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-08T18:26:54.204830291Z", "changedAt": "2026-10-08T18:26:54.204830291Z", "fingerprint": "2750d7de8d7c" }, { "url": "https://www.cartesia.ai/legal/terms", "kind": "terms", "status": 200, "checkedAt": "2026-10-08T18:26:56.591248396Z", "changedAt": "2026-10-08T18:26:56.591248396Z", "fingerprint": "a146b5cf872a" } ], "github": { "repo": "cartesia-ai/cartesia-python", "checkedAt": "2026-11-02T08:37:37.378374658Z", "stars": 138, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-30T18:24:19Z", "openIssues": 1, "openPRs": 8, "issuesOpened90d": 1, "issuesClosed90d": 1, "prsMerged90d": 4, "ci": { "branch": "main", "runs": 50, "success": 33, "failure": 0, "other": 17, "latest": "skipped", "latestAt": "2026-10-23T17:43:01Z" }, "replies": { "sampled": 14, "unanswered": 1, "medianDays": 54.7 } }, "updatedAt": "2026-11-07T18:20:16.163517449Z" } }, "answer": "Smallest.ai Lightning TTS scores 64.4 (B) on agent readiness against Cartesia Sonic TTS API + MCP's 61.9 (C), and leads in 4 of 7 scored categories. Cartesia Sonic TTS API + MCP leads on reliability and maintenance \u0026 community.", "b": { "slug": "smallest-lightning-tts", "name": "Smallest.ai Lightning TTS", "vendor": "Smallest AI", "vendorUrl": "https://smallest.ai", "kind": "model", "category": "text-to-speech", "summary": "Smallest AI's Lightning text-to-speech API turns text into 44.1 kHz speech over HTTP, server-sent events or WebSocket, with the Lightning v3.1 and v3.1 Pro models in up to 31 languages, pronunciation dictionaries and word timestamps.", "url": "https://www.anchorterminal.com/tools/smallest-lightning-tts", "markdownUrl": "https://www.anchorterminal.com/tools/smallest-lightning-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/smallest-lightning-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/smallest-lightning-tts.json", "dns": "smallest-lightning-tts.grade.anchorterminal.com", "repo": "https://github.com/smallest-inc/smallest-python-sdk", "transports": [ "http", "websocket" ], "packages": [ { "registry": "pypi", "name": "smallestai" }, { "registry": "npm", "name": "smallestai" }, { "registry": "npm", "name": "@developer-smallestai/smallest-mcp-server" } ], "auth": "api-key", "authNotes": "Bearer `sk_` API key created in the dashboard after a browser signup, shared by every model and the Voice Agents API. Keys are shown once, revoked by deleting them and carry no scopes. Servers can mint `wat_` access tokens for browsers (30 to 900 seconds, inference routes only).", "pricing": "usage", "pricingNotes": "Pay as you go at $0.175 per 10,000 characters for Lightning v3.1 and $0.195 for Lightning v3.1 Pro. $10 in trial credits. Pay as you go is capped at 450M characters a month. Enterprise pricing, SLA and zero data retention by quote.", "priceSummary": "Pay per use", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the docs, OpenAPI file or pricing page (checked 2026-11-06). Credits are bought with a card on file.", "endpoints": [] }, "toolCount": 0, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-11-06" }, "docsUrl": "https://docs.smallest.ai/models/text-to-speech/overview", "llmsTxt": "https://docs.smallest.ai/llms.txt", "openapi": "https://docs.smallest.ai/openapi/models-api.json", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.languages" ], "tags": [ "hosted", "usage", "closed-source", "python", "typescript", "openapi", "llms-txt", "streaming", "mcp", "enterprise", "self-hosted" ], "lastRelease": "2026-11-02", "graded": true, "anchor": { "graded": true, "score": 64.4, "grade": "B", "agentReady": false, "rank": 469, "ranked": true, "rankOf": 1486, "categoryRank": 9, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 72, "maintenance": 68, "payments": 40, "reliability": 58, "schema": 92, "security": 52, "transparency": 70 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "Lightning streams speech over HTTP, SSE or WebSocket with OpenAPI and AsyncAPI files and public prices of $0.175 to $0.195 per 10,000 characters. The default model retires on 30 November with 28 days' notice, published concurrency limits disagree, and the shared API failed in every region on five days in September.", "bestFor": "Low-latency speech for voice agents, with English, Hindi code-switching and Indic voices.", "strengths": [ "OpenAPI 3.1 and AsyncAPI 2.6 files cover the sync, SSE and WebSocket routes, with llms.txt and Markdown copies of every page", "Public prices of $0.175 per 10,000 characters for v3.1 and $0.195 for v3.1 Pro, with $10 of trial credits", "Pronunciation dictionaries, number and date reading controls, word timestamps and eight output formats", "A deprecations page with dates and migration steps, and dated preview checkpoints that run 30 days", "Region-pinned hosts in Mumbai and Oregon" ], "weaknesses": [ "`lightning_v3.1`, the default model, retires on 30 November 2026 after a 2 November notice, and clones made on it stop working", "Concurrency is published as 1, 10 and 15 on three different pages", "Health checks on the shared API failed in all three regions on 9, 10, 13, 14 and 15 September 2026, the longest about 64 minutes", "Keys grant full account access with no scopes, and the docs pass keys or tokens as URL query parameters on WebSockets", "No SSML, and zero data retention only on Enterprise or a $1,000 a month add-on" ], "agentNotes": [ "Always send `\"model\": \"lightning_v3.1_pro\"`, since requests with no model go to a model that retires on 30 November 2026", "Pick voices from `GET /waves/v1/lightning-v3.1-pro/get_voices`, because the v3.1 and v3.1 Pro catalogues differ", "Keep each request under 8,000 characters and split longer text", "Treat 429 as the concurrency ceiling and retry with backoff from 500 ms to 30 s, honouring Retry-After", "Fix names and acronyms with a pronunciation dictionary, since SSML isn't accepted" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 64.4 } ], "editorialScores": { "ergonomics": 72, "maintenance": 68, "payments": 40, "reliability": 58, "schema": 92, "security": 52, "transparency": 52 }, "provenanceScore": 87, "checked": { "categories": { "ergonomics": "2026-11-06", "maintenance": "2026-11-06", "payments": "2026-11-06", "reliability": "2026-11-06", "schema": "2026-11-06", "security": "2026-11-06", "transparency": "2026-11-06" }, "last": "2026-11-06", "oldest": "2026-11-06", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "pip install smallestai", "http": "curl -X POST \"https://api.smallest.ai/waves/v1/tts\" \\\n -H \"Authorization: Bearer $SMALLEST_API_KEY\" -H \"Content-Type: application/json\" -H \"Accept: audio/wav\" \\\n -d '{\"text\": \"Hello from Smallest AI.\", \"voice_id\": \"meher\", \"model\": \"lightning_v3.1_pro\", \"sample_rate\": 24000, \"output_format\": \"wav\"}' \\\n --output hello.wav", "claudeCode": "claude mcp add smallest -- npx -y @developer-smallestai/smallest-mcp-server" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/smallest-lightning-tts" }, "sameCompany": [ "smallest-pulse-stt", "smallest-voice-clone" ], "area": "voice", "unitPrices": [ { "item": "Lightning v3.1", "unit": "1m-chars", "usd": 17.5, "note": "$0.175 per 10,000 characters, pay as you go; model retiring 30 November 2026" }, { "item": "Lightning v3.1 Pro", "unit": "1m-chars", "usd": 19.5, "note": "$0.195 per 10,000 characters, pay as you go" } ], "provenance": { "legalEntity": "Smallest, Inc.", "domain": "smallest.ai", "domainRegistered": "2023-09-02", "endpointOnVendorDomain": true, "terms": "https://smallest.ai/terms-of-service", "privacy": "https://smallest.ai/privacy-policy", "statusPage": "https://status.smallest.ai/", "changelog": "https://docs.smallest.ai/changelog/models", "securityTxt": "valid", "checked": "2026-11-06", "notes": [ "The terms of service (effective 21 October 2026) name Smallest Inc., 311 California Street, Suite 320, San Francisco, under California law. The privacy policy (effective 18 September 2026) names Smallest, Inc. with a registered office in Lewes, Delaware.", "The terms forbid accessing or searching the services with spiders, robots, crawlers or similar data mining tools except through means Smallest makes available. Only public pages were read, with no account.", "smallest.ai/robots.txt allows all crawlers including ClaudeBot, with Content-Signal ai-train=yes, search=yes, ai-input=yes. docs.smallest.ai/robots.txt allows all paths except /api/fern-docs/.", "/.well-known/security.txt names security@smallest.ai and expires 31 December 2026. /security.txt returns 404.", "RDAP gives smallest.ai a registration date of 2 September 2023.", "Every docs page served as Markdown opens with a block addressed to AI assistants that says which models to prefer. It was read as data, not followed.", "firstReleased is left empty. No dated launch of the Models API was found on a page our reader may fetch." ], "score": 87 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/smallest-lightning-tts.json", "live": { "slug": "smallest-lightning-tts", "vendorStatus": { "page": "https://status.smallest.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:48:45.761951958Z" }, "versions": [ { "registry": "github", "name": "smallest-inc/smallest-python-sdk", "version": "v2.1.0", "released": "2025-03-04", "seenAt": "2026-11-07T00:06:35.435989203Z" }, { "registry": "npm", "name": "@developer-smallestai/smallest-mcp-server", "version": "0.11.2", "seenAt": "2026-11-07T00:06:33.7720962Z" }, { "registry": "npm", "name": "smallestai", "version": "1.0.1", "seenAt": "2026-11-07T00:06:32.999034745Z" }, { "registry": "pypi", "name": "smallestai", "version": "5.14.0", "released": "2026-10-07", "seenAt": "2026-11-07T00:06:32.730014258Z" } ], "githubStars": 42, "npmWeekly": 149, "pypiWeekly": 850, "securityTxt": { "url": "https://smallest.ai/.well-known/security.txt", "state": "valid", "expires": "2026-12-31T23:59:59.000Z", "checkedAt": "2026-11-07T16:01:21.76871346Z" }, "llmsTxt": { "url": "https://docs.smallest.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:33:56.775686182Z" }, "pages": [ { "url": "https://docs.smallest.ai/changelog/models", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:08:02.477867618Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "5541546461b9" }, { "url": "https://smallest.ai/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:20:10.527086718Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "2296cee567f0" }, { "url": "https://smallest.ai/terms-of-service", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:20:12.776174427Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "27186e5f758e" } ], "updatedAt": "2026-11-07T16:01:21.76871346Z" } }, "edges": [ { "by": 16, "category": "maintenance", "leads": "cartesia-tts", "name": "Maintenance \u0026 community", "reasons": { "a": "Read as a model, on the lines deepgram-tts, gladia-stt and cartesia-ink-stt use for hosted speech models (recency 30, dated releases 10, deprecation notice 10, support 15, issues 10, SDKs 15, health 10). `cartesia-mcp`, whose `text_to_speech` tool calls Sonic, released 0.28.1 on 30 October 2026 after 0.27.0 (20 October), 0.27.1 (23 October) and 0.28.0 (27 October), and `sonic-3.6-2026-08-27` is the newest snapshot (30). From 4 August the Python and TypeScript SDKs released 4.0.0, 4.0.1, 4.1.0 and 4.2.0 (14 August to 2 September) and the MCP server more than ten releases (10). Sonic-2, Sonic Turbo and `sonic-3-2025-10-27` were sunset after 20 October 2026, announced in the July changelog, about 83 days ahead. The deprecations page dates each sunset but states no minimum notice period (5 of 10). The changelog has Text-to-Speech entries every month from May to September 2026, dated by month only, and no October entry, the same reading as cartesia-ink-stt (11 of 15; was 5). The Python SDK repository had 4 open issues on 9 October per the cartesia-ink-stt check, not re-read on 2 November since GitHub's pages answered 403 (5 of 10; was 7 on a 1 October count of one). Official `cartesia` and `@cartesia/cartesia-js` SDKs at 4.2.0 (2 September 2026), generated for API version 2026-08-14 (15). CI, release-please and lock files in both SDK repositories, with dependency updates merged on 23 October (8 of 10). 30+10+5+11+5+15+8 = 84.", "b": "Read as a model. The newest Lightning changelog entry is dated 2 November 2026 (the v3.1 retirement notice), after a preview checkpoint on 29 October (30). Dated Lightning entries on 10, 23 and 28 August, 29 September, 14, 17 and 29 October and 2 November count, less 5 for churn, because the default model retires 28 days after its notice and clones made on it stop working (15 of 20). Public changelog, email support and a Discord server, with no evidence read of how they answer (10 of 15). The Python SDK `smallestai` 5.14.0 dates from 7 October, but the npm Node SDK has not been published since May 2025 (8 of 15). The Python SDK repository runs CI and release workflows, but has no licence file (5 of 10). Total 68." }, "scores": { "a": 84, "b": 68 } }, { "by": 15, "category": "reliability", "leads": "cartesia-tts", "name": "Reliability", "reasons": { "a": "incident.io status page at status.cartesia.ai with TTS components for the US, EU, APAC and Australia and a dated history (20). feed.rss, read on 2 November, lists these items touching TTS from 4 August to 2 November 2026. Intermittent TTS timeouts on 5 August (21:25 to 23:21 per the 1 October reading), Agents telephony failing in the US on 7 August, region validation failing some TTS requests on 14 August, elevated time to first audio for sonic-3.5 and sonic-3 in the EU and US on 21 August, connection errors in the US on 2 September (\"subsequent retries were successful\"), WebSocket throttling in APAC on 3 September and degraded API performance in the US on 7 October. Each touches part of the requests, one region or one product, so each reads as partial and minor under this run's incident rule. The 1 October reading counted 5 August as a major (10), and the 1 August API-wide incident has left the window. Minor incidents only (20), as cartesia-ink-stt on the same page. TTS concurrency published per plan, 2 on Free, 3 on Pro, 5 on Startup and 15 on Scale (15). A 429 is documented when the limit is hit, with no Retry-After or backoff guidance in the docs, though the Python SDK retries 429 and 5xx with backoff (8). No SLA found, and the Terms disclaim availability (0). `sonic-3.6` is GA, while emotion tags and `sonic-preview` are beta (10). 20+20+15+8+0+10 = 73.", "b": "BetterStack status page at status.smallest.ai with components for the Global, India and USA APIs (one health check covers the Agents and Models APIs), docs, the app and Electron, and per-component history (20). In the 90 days from 8 August the health checks on the shared API failed in all three regions on 9, 10, 13, 14 and 15 September (about 8, 21, 33, 17 and 64 minutes of flapping), in the Global and India regions on 11 and 17 September (12 minutes each), and in the USA region alone on 1, 3, 5, 12, 21 and 30 September (6 to 62 minutes) and 6 October (12 minutes). Outages in every region at once are read as wide errors, so several majors (0). Limits are published with numbers but disagree. The limits page says one TTS request at a time per account with up to five sockets, the Lightning v3.1 Pro card says 10 concurrent and the pricing page says 15 streams and 100 requests a minute on pay as you go (8 of 15). 429 is documented with exponential backoff from 500 ms to 30 s and Retry-After when present, and the limits page tells clients to expect 429s at the concurrency ceiling (15). An infrastructure SLA of 99.99 per cent is named for Enterprise only, with no terms, and the terms disclaim any availability commitment (5 of 10). `lightning_v3.1_pro` is stable and only the dated checkpoint is preview (10). 20 + 0 + 8 + 15 + 5 + 10 = 58." }, "scores": { "a": 73, "b": 58 } }, { "by": 10, "category": "payments", "leads": "smallest-lightning-tts", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0). Plan prices and credit allowances are public, about 1 credit a character, but there's no plain dollar price per character outside the plans (10). Free plan with 20,000 credits a month (about 27 minutes), no card step mentioned, non-commercial use only (20). A person signs up in a browser (0).", "b": "No x402, MPP or L402 (0). Per-character prices for both models published without a login (20). Pay as you go starts with $10 of trial credits, which the terms also describe, and no page says a card is needed to claim them, read as inworld-tts's free plan was (20). A person signs up in a browser at app.smallest.ai and creates the key in the dashboard, and top-ups go to a card on file (0). Total 40." }, "scores": { "a": 30, "b": 40 } }, { "by": 7, "category": "ergonomics", "leads": "smallest-lightning-tts", "name": "Agent ergonomics", "reasons": { "a": "API reading of the checklist. WAV, MP3 or raw PCM from 8 to 48 kHz, over bytes, SSE or a WebSocket that takes streamed LLM text, with word timestamps on request (22 of 25). Voice lists paginate with SDK iterators, filters not confirmed, and no per-request length cap is documented (10 of 20). Errors are HTTP statuses mapped to SDK exceptions without TTS-specific codes (10 of 20). The SDK retries 429 and 5xx with backoff. We found no seed and didn't confirm the billing rule for failed calls (10 of 20). Four required fields plus the version header, and official Python and TypeScript SDKs (13 of 15).", "b": "API reading of the checklist. Eight output formats, a choice of sample rate and word timestamps only when asked (22 of 25). Voices are listed per model and the docs say they filter by language and accent. Paging wasn't confirmed (14 of 20). Errors carry `error` and `message` fields with a shared status-code guide, without TTS-specific codes (14 of 20). Synthesis is stateless and `request_id` is echoed for correlation, but there is no idempotency key and billing of a retried request isn't stated (10 of 20). Two required fields, `text` and `voice_id`, but the default model retires on 30 November. Official Python and Node SDKs, with the Node SDK last published in May 2025 (12 of 15). Total 72." }, "scores": { "a": 65, "b": 72 } }, { "by": 6, "category": "schema", "leads": "smallest-lightning-tts", "name": "Schema \u0026 documentation", "reasons": { "a": "OpenAPI files for the latest and each dated API version, plus AsyncAPI files for the WebSocket, are listed in llms.txt (25). llms.txt and Markdown pages (10). A page compares the bytes, SSE and WebSocket endpoints and says which to use for what, and model pages explain dated snapshots (15 of 20). Typed request bodies with enums for container, encoding and sample rate, and a 0.6 to 1.5 range on `speed` (13 of 15). Examples in curl and both SDKs, but no error responses documented for the TTS endpoints, only SDK exception classes (8 of 15). Dated `Cartesia-Version` header, dated model snapshots that never change, and a monthly changelog (15).", "b": "OpenAPI 3.1 for the sync and SSE routes and AsyncAPI 2.6 for the WebSocket, with request and event schemas (25). llms.txt and a Markdown copy of every page (10). A transport guide, model cards and the compare page say which model and transport suit which job, but changelog entries correct the language lists and enums the docs and spec carried (15 of 20). Typed fields with enums for model, sample rate, language and output format, an 8,000-character limit and pattern rules on `session_id` and `request_id` (14 of 15). Examples in curl, Python and JavaScript, with error bodies on the reference and a shared error page (13 of 15). Versioned `/v1` paths, a dated Lightning changelog and dated preview checkpoints (15). Total 92." }, "scores": { "a": 86, "b": 92 } }, { "by": 5, "category": "security", "leads": "smallest-lightning-tts", "name": "Security \u0026 auth", "reasons": { "a": "Model reading of the checklist (credential, training, retention, operator visibility, programme), on the same evidence and values as cartesia-ink-stt. Standard and admin API keys are separate types, revocable, and a server can mint short-lived access tokens with TTS, STT and agent grants, but no key is scoped to TTS (26). Browsers pass the access token in the WebSocket query string, which the authentication guide documents (\"In browsers, use an access token and query parameters instead\"), and this run takes the full 10 off for a reusable token in a URL, as for cartesia-ink-stt and every Google API listing (16 of 30; the 1 October check didn't deduct). The Terms (last revised 14 June 2024, re-read on 2 November) say inputs, outputs and interactions may be used to train models unless otherwise agreed, with an opt-out form (5 of 20, aligned with cartesia-ink-stt; was 10). Zero data retention is Enterprise only and no retention period is published for other plans (5 of 15). Credit usage and key metadata are readable through admin endpoints and the usage dashboard, no per-call audit log found (7 of 15, aligned; was 8). security.txt at www.cartesia.ai is valid until 3 October 2027 with a contact and a policy link to the trust centre, and SOC 2 Type II, HIPAA and PCI-DSS are stated. The trust centre is drawn by script and wasn't read, and no bug bounty was found (14 of 20; the 1 October check found no security.txt, 10). 16+5+5+7+14 = 47.", "b": "Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. Plain `sk_` keys per organisation, shown once, revoked at once and deletable, with one key per environment advised. The docs say a key grants full account access, and no scope is offered. Short-lived access tokens (`wat_`, 30 to 900 seconds) cover only inference routes and can't mint tokens (22 of 30). The error reference documents the key as a `?token=` query parameter for browser WebSockets, and the token guide passes access tokens as `?api_key=` on the STT socket, so 10 off (12 of 30). The terms (21 October 2026) say Smallest won't use user content or input to train or improve its services. The privacy policy (18 September 2026) lists improving the services with machine learning as a use of usage data and doesn't address uploaded audio or text either way (15 of 20). Zero data retention and the `x-expire-content` header are Enterprise only, or a $1,000 a month HIPAA add-on on pay as you go. Other plans keep content readable in logs and the dashboard, with no retention period published (5 of 15). Usage is tracked per key, request rows sit in a dashboard log viewer, and every response carries `x-request-id`. No audit log of key actions was found (10 of 15). security.txt is valid to 31 December 2026 and the site footer claims SOC 2, GDPR and HIPAA compliance, while the pricing page lists SOC 2 compliance only on Enterprise. No bug bounty, disclosure policy or public advisories found (10 of 20). Total 52." }, "scores": { "a": 47, "b": 52 } } ], "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "Cartesia", "b": "Smallest AI", "name": "Vendor" }, { "a": "https://api.cartesia.ai", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP, stdio", "b": "HTTP, websocket", "name": "Transports" }, { "a": "OAuth or key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Pay per use", "name": "Pricing" }, { "a": "$38 per 1M characters", "b": "not published", "name": "Price for text-to-speech" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Apache-2.0 (SDKs)", "b": "none", "name": "Licence" }, { "a": "19", "b": "0", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-30", "b": "2026-11-02", "name": "Last release" }, { "a": "2024-06-14", "b": "no date given", "name": "Terms last updated" }, { "a": "2024-06-14", "b": "no date given", "name": "Privacy policy last updated" }, { "a": "yes, with an opt-out", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "yes", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "yes", "name": "Terms or service can change without notice" }, { "a": "yes", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "133 stars, 166k npm/wk, 177k PyPI/wk", "b": "none", "name": "Popularity" }, { "a": "3/5 (2)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Smallest.ai Lightning TTS scores 64.4 (B) on agent readiness against Cartesia Sonic TTS API + MCP's 61.9 (C), and leads in 4 of 7 scored categories. Cartesia Sonic TTS API + MCP leads on reliability and maintenance \u0026 community.", "question": "Which is better for AI agents, Cartesia Sonic TTS API + MCP or Smallest.ai Lightning TTS?" }, { "answer": "Cartesia Sonic TTS API + MCP takes an API key or an OAuth sign-in. Smallest.ai Lightning TTS needs an API key.", "question": "Do Cartesia Sonic TTS API + MCP and Smallest.ai Lightning TTS need an API key?" }, { "answer": "Cartesia Sonic TTS API + MCP has a hosted endpoint at https://api.cartesia.ai. No hosted endpoint is listed for Smallest.ai Lightning TTS.", "question": "Can an agent call Cartesia Sonic TTS API + MCP and Smallest.ai Lightning TTS without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 73 against 58", "Maintenance \u0026 community, 84 against 68" ], "also": [ "A hosted endpoint, with nothing to install", "Runs on your own machine" ], "goodFor": "Real-time voice agents that stream LLM output straight into speech and need stable, pinnable models.", "slug": "cartesia-tts", "watchFor": "Pronunciation dictionaries on Sonic 3.6 began ignoring case by default in September 2026, with no earlier notice found" }, { "aheadOn": [ "Schema \u0026 documentation, 92 against 86", "Agent ergonomics, 72 against 65", "Security \u0026 auth, 52 against 47", "Payments \u0026 pricing, 40 against 30" ], "also": [ "No incidents deducted, where Cartesia Sonic TTS API + MCP loses 3 points for them" ], "goodFor": "Low-latency speech for voice agents, with English, Hindi code-switching and Indic voices.", "slug": "smallest-lightning-tts", "watchFor": "`lightning_v3.1`, the default model, retires on 30 November 2026 after a 2 November notice, and clones made on it stop working" } ], "history": { "cartesia-tts": [ { "causes": [ "evidence", "correction", "event" ], "date": "2026-11-02", "delta": -2.1, "from": 64, "fromGrade": "B", "to": 61.9, "toGrade": "C" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.2, "from": 63.8, "fromGrade": "B", "to": 64, "toGrade": "B" }, { "causes": [ "method" ], "date": "2026-10-08", "delta": -0.4, "from": 64.2, "fromGrade": "B", "to": 63.8, "toGrade": "B" } ], "smallest-lightning-tts": null }, "job": { "capability": "speech.tts", "name": "Text-to-speech" }, "others": [ { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts.json", "title": "Amazon Polly vs Cartesia Sonic TTS API + MCP", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.json", "title": "Amazon Polly vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-cartesia-tts.json", "title": "Azure AI Speech text-to-speech vs Cartesia Sonic TTS API + MCP", "url": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-cartesia-tts" }, { "json": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-smallest-lightning-tts.json", "title": "Azure AI Speech text-to-speech vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-deepgram-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Deepgram Text-to-Speech (Aura-2, Flux TTS)", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-deepgram-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-elevenlabs-tts.json", "title": "Cartesia Sonic TTS API + MCP vs ElevenLabs Text to Speech API + MCP", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-elevenlabs-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-fish-audio-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Fish Audio TTS API", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-fish-audio-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice.json", "title": "Cartesia Sonic TTS API + MCP vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-minimax-speech.json", "title": "Cartesia Sonic TTS API + MCP vs MiniMax Speech (T2A)", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-minimax-speech" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-murf-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Murf TTS API + MCP", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-murf-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-playht-tts.json", "title": "Cartesia Sonic TTS API + MCP vs PlayHT Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-playht-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-resemble-ai-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Resemble AI Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-resemble-ai-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Rime TTS API + MCP", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-soniox-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/deepgram-tts-vs-smallest-lightning-tts.json", "title": "Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/deepgram-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-smallest-lightning-tts.json", "title": "ElevenLabs Text to Speech API + MCP vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-smallest-lightning-tts.json", "title": "Fish Audio TTS API vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-smallest-lightning-tts.json", "title": "Google Cloud Text-to-Speech vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-smallest-lightning-tts.json", "title": "HeyGen Voice vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-smallest-lightning-tts.json", "title": "Inworld Realtime TTS-2 vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/minimax-speech-vs-smallest-lightning-tts.json", "title": "MiniMax Speech (T2A) vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/minimax-speech-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/murf-tts-vs-smallest-lightning-tts.json", "title": "Murf TTS API + MCP vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/murf-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/playht-tts-vs-smallest-lightning-tts.json", "title": "PlayHT Text-to-Speech API vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/playht-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/resemble-ai-tts-vs-smallest-lightning-tts.json", "title": "Resemble AI Text-to-Speech API vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/resemble-ai-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/rime-tts-vs-smallest-lightning-tts.json", "title": "Rime TTS API + MCP vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/rime-tts-vs-smallest-lightning-tts" }, { "json": "https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts.json", "title": "Smallest.ai Lightning TTS vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts" } ], "panel": null, "scores": [ { "by": 15, "cartesia-tts": 73, "edge": "cartesia-tts", "key": "reliability", "name": "Reliability", "smallest-lightning-tts": 58, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 6, "cartesia-tts": 86, "edge": "smallest-lightning-tts", "key": "schema", "name": "Schema \u0026 documentation", "smallest-lightning-tts": 92, "weight": 13 }, { "by": 7, "cartesia-tts": 65, "edge": "smallest-lightning-tts", "key": "ergonomics", "name": "Agent ergonomics", "smallest-lightning-tts": 72, "weight": 13 }, { "by": 5, "cartesia-tts": 47, "edge": "smallest-lightning-tts", "key": "security", "name": "Security \u0026 auth", "smallest-lightning-tts": 52, "weight": 14 }, { "by": 10, "cartesia-tts": 30, "edge": "smallest-lightning-tts", "key": "payments", "name": "Payments \u0026 pricing", "smallest-lightning-tts": 40, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 16, "cartesia-tts": 84, "edge": "cartesia-tts", "key": "maintenance", "name": "Maintenance \u0026 community", "smallest-lightning-tts": 68, "weight": 7 }, { "by": 3, "cartesia-tts": 73, "edge": "cartesia-tts", "key": "transparency", "name": "Transparency \u0026 trust", "smallest-lightning-tts": 70, "weight": 7 } ], "summary": "Smallest.ai Lightning TTS scores 64.4 (B) on agent readiness against Cartesia Sonic TTS API + MCP's 61.9 (C), and leads in 4 of 7 scored categories. Cartesia Sonic TTS API + MCP leads on reliability and maintenance \u0026 community. Both do text-to-speech.", "tasks": [ { "a": "$0.34 to $0.59", "b": "$0.16 to $0.18", "cheaper": "smallest-lightning-tts", "task": "Narrate a 9,000-character script", "what": "about 1,500 words" } ], "tutorials": [], "verdicts": { "cartesia-tts": "The WebSocket accepts streamed LLM text with contexts, flushing and word timestamps, and dated Sonic snapshots never change. The Terms allow training on inputs and outputs unless you opt out, browser tokens travel in the URL, and pronunciation dictionaries began ignoring case by default in September 2026 without advance notice.", "smallest-lightning-tts": "Lightning streams speech over HTTP, SSE or WebSocket with OpenAPI and AsyncAPI files and public prices of $0.175 to $0.195 per 10,000 characters. The default model retires on 30 November with 28 days' notice, published concurrency limits disagree, and the shared API failed in every region on five days in September." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts", "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts.min.md" }, "markdown": "Smallest.ai Lightning TTS scores 64.4 (B) on agent readiness against Cartesia Sonic TTS API + MCP's 61.9 (C), and leads in 4 of 7 scored categories. Cartesia Sonic TTS API + MCP leads on reliability and maintenance \u0026 community. Both do text-to-speech.\n\n- Cartesia Sonic TTS API + MCP: grade C, 61.9/100, rank #582 of 1486. Markdown https://www.anchorterminal.com/tools/cartesia-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json\n- Smallest.ai Lightning TTS: grade B, 64.4/100, rank #469 of 1486. Markdown https://www.anchorterminal.com/tools/smallest-lightning-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/smallest-lightning-tts.json\n- Best text-to-speech APIs for AI agents: https://www.anchorterminal.com/best/text-to-speech/index.md\n- All 148 tts comparisons: https://www.anchorterminal.com/compare/text-to-speech/index.md\n\n## Which one, for what\n\n### Cartesia Sonic TTS API + MCP (C)\n\nGood for: Real-time voice agents that stream LLM output straight into speech and need stable, pinnable models.\n\nAhead on:\n- Reliability, 73 against 58\n- Maintenance \u0026 community, 84 against 68\n\nAlso in its favour:\n- A hosted endpoint, with nothing to install\n- Runs on your own machine\n\nWatch for: Pronunciation dictionaries on Sonic 3.6 began ignoring case by default in September 2026, with no earlier notice found\n\n### Smallest.ai Lightning TTS (B)\n\nGood for: Low-latency speech for voice agents, with English, Hindi code-switching and Indic voices.\n\nAhead on:\n- Schema \u0026 documentation, 92 against 86\n- Agent ergonomics, 72 against 65\n- Security \u0026 auth, 52 against 47\n- Payments \u0026 pricing, 40 against 30\n\nAlso in its favour:\n- No incidents deducted, where Cartesia Sonic TTS API + MCP loses 3 points for them\n\nWatch for: `lightning_v3.1`, the default model, retires on 30 November 2026 after a 2 November notice, and clones made on it stop working\n\n\n## Why the edge\n\n### Maintenance \u0026 community: Cartesia Sonic TTS API + MCP +16\n\n- Cartesia Sonic TTS API + MCP (84): Read as a model, on the lines deepgram-tts, gladia-stt and cartesia-ink-stt use for hosted speech models (recency 30, dated releases 10, deprecation notice 10, support 15, issues 10, SDKs 15, health 10). `cartesia-mcp`, whose `text_to_speech` tool calls Sonic, released 0.28.1 on 30 October 2026 after 0.27.0 (20 October), 0.27.1 (23 October) and 0.28.0 (27 October), and `sonic-3.6-2026-08-27` is the newest snapshot (30). From 4 August the Python and TypeScript SDKs released 4.0.0, 4.0.1, 4.1.0 and 4.2.0 (14 August to 2 September) and the MCP server more than ten releases (10). Sonic-2, Sonic Turbo and `sonic-3-2025-10-27` were sunset after 20 October 2026, announced in the July changelog, about 83 days ahead. The deprecations page dates each sunset but states no minimum notice period (5 of 10). The changelog has Text-to-Speech entries every month from May to September 2026, dated by month only, and no October entry, the same reading as cartesia-ink-stt (11 of 15; was 5). The Python SDK repository had 4 open issues on 9 October per the cartesia-ink-stt check, not re-read on 2 November since GitHub's pages answered 403 (5 of 10; was 7 on a 1 October count of one). Official `cartesia` and `@cartesia/cartesia-js` SDKs at 4.2.0 (2 September 2026), generated for API version 2026-08-14 (15). CI, release-please and lock files in both SDK repositories, with dependency updates merged on 23 October (8 of 10). 30+10+5+11+5+15+8 = 84.\n- Smallest.ai Lightning TTS (68): Read as a model. The newest Lightning changelog entry is dated 2 November 2026 (the v3.1 retirement notice), after a preview checkpoint on 29 October (30). Dated Lightning entries on 10, 23 and 28 August, 29 September, 14, 17 and 29 October and 2 November count, less 5 for churn, because the default model retires 28 days after its notice and clones made on it stop working (15 of 20). Public changelog, email support and a Discord server, with no evidence read of how they answer (10 of 15). The Python SDK `smallestai` 5.14.0 dates from 7 October, but the npm Node SDK has not been published since May 2025 (8 of 15). The Python SDK repository runs CI and release workflows, but has no licence file (5 of 10). Total 68.\n\n### Reliability: Cartesia Sonic TTS API + MCP +15\n\n- Cartesia Sonic TTS API + MCP (73): incident.io status page at status.cartesia.ai with TTS components for the US, EU, APAC and Australia and a dated history (20). feed.rss, read on 2 November, lists these items touching TTS from 4 August to 2 November 2026. Intermittent TTS timeouts on 5 August (21:25 to 23:21 per the 1 October reading), Agents telephony failing in the US on 7 August, region validation failing some TTS requests on 14 August, elevated time to first audio for sonic-3.5 and sonic-3 in the EU and US on 21 August, connection errors in the US on 2 September (\"subsequent retries were successful\"), WebSocket throttling in APAC on 3 September and degraded API performance in the US on 7 October. Each touches part of the requests, one region or one product, so each reads as partial and minor under this run's incident rule. The 1 October reading counted 5 August as a major (10), and the 1 August API-wide incident has left the window. Minor incidents only (20), as cartesia-ink-stt on the same page. TTS concurrency published per plan, 2 on Free, 3 on Pro, 5 on Startup and 15 on Scale (15). A 429 is documented when the limit is hit, with no Retry-After or backoff guidance in the docs, though the Python SDK retries 429 and 5xx with backoff (8). No SLA found, and the Terms disclaim availability (0). `sonic-3.6` is GA, while emotion tags and `sonic-preview` are beta (10). 20+20+15+8+0+10 = 73.\n- Smallest.ai Lightning TTS (58): BetterStack status page at status.smallest.ai with components for the Global, India and USA APIs (one health check covers the Agents and Models APIs), docs, the app and Electron, and per-component history (20). In the 90 days from 8 August the health checks on the shared API failed in all three regions on 9, 10, 13, 14 and 15 September (about 8, 21, 33, 17 and 64 minutes of flapping), in the Global and India regions on 11 and 17 September (12 minutes each), and in the USA region alone on 1, 3, 5, 12, 21 and 30 September (6 to 62 minutes) and 6 October (12 minutes). Outages in every region at once are read as wide errors, so several majors (0). Limits are published with numbers but disagree. The limits page says one TTS request at a time per account with up to five sockets, the Lightning v3.1 Pro card says 10 concurrent and the pricing page says 15 streams and 100 requests a minute on pay as you go (8 of 15). 429 is documented with exponential backoff from 500 ms to 30 s and Retry-After when present, and the limits page tells clients to expect 429s at the concurrency ceiling (15). An infrastructure SLA of 99.99 per cent is named for Enterprise only, with no terms, and the terms disclaim any availability commitment (5 of 10). `lightning_v3.1_pro` is stable and only the dated checkpoint is preview (10). 20 + 0 + 8 + 15 + 5 + 10 = 58.\n\n### Payments \u0026 pricing: Smallest.ai Lightning TTS +10\n\n- Cartesia Sonic TTS API + MCP (30): No x402, MPP or L402 (0). Plan prices and credit allowances are public, about 1 credit a character, but there's no plain dollar price per character outside the plans (10). Free plan with 20,000 credits a month (about 27 minutes), no card step mentioned, non-commercial use only (20). A person signs up in a browser (0).\n- Smallest.ai Lightning TTS (40): No x402, MPP or L402 (0). Per-character prices for both models published without a login (20). Pay as you go starts with $10 of trial credits, which the terms also describe, and no page says a card is needed to claim them, read as inworld-tts's free plan was (20). A person signs up in a browser at app.smallest.ai and creates the key in the dashboard, and top-ups go to a card on file (0). Total 40.\n\n### Agent ergonomics: Smallest.ai Lightning TTS +7\n\n- Cartesia Sonic TTS API + MCP (65): API reading of the checklist. WAV, MP3 or raw PCM from 8 to 48 kHz, over bytes, SSE or a WebSocket that takes streamed LLM text, with word timestamps on request (22 of 25). Voice lists paginate with SDK iterators, filters not confirmed, and no per-request length cap is documented (10 of 20). Errors are HTTP statuses mapped to SDK exceptions without TTS-specific codes (10 of 20). The SDK retries 429 and 5xx with backoff. We found no seed and didn't confirm the billing rule for failed calls (10 of 20). Four required fields plus the version header, and official Python and TypeScript SDKs (13 of 15).\n- Smallest.ai Lightning TTS (72): API reading of the checklist. Eight output formats, a choice of sample rate and word timestamps only when asked (22 of 25). Voices are listed per model and the docs say they filter by language and accent. Paging wasn't confirmed (14 of 20). Errors carry `error` and `message` fields with a shared status-code guide, without TTS-specific codes (14 of 20). Synthesis is stateless and `request_id` is echoed for correlation, but there is no idempotency key and billing of a retried request isn't stated (10 of 20). Two required fields, `text` and `voice_id`, but the default model retires on 30 November. Official Python and Node SDKs, with the Node SDK last published in May 2025 (12 of 15). Total 72.\n\n### Schema \u0026 documentation: Smallest.ai Lightning TTS +6\n\n- Cartesia Sonic TTS API + MCP (86): OpenAPI files for the latest and each dated API version, plus AsyncAPI files for the WebSocket, are listed in llms.txt (25). llms.txt and Markdown pages (10). A page compares the bytes, SSE and WebSocket endpoints and says which to use for what, and model pages explain dated snapshots (15 of 20). Typed request bodies with enums for container, encoding and sample rate, and a 0.6 to 1.5 range on `speed` (13 of 15). Examples in curl and both SDKs, but no error responses documented for the TTS endpoints, only SDK exception classes (8 of 15). Dated `Cartesia-Version` header, dated model snapshots that never change, and a monthly changelog (15).\n- Smallest.ai Lightning TTS (92): OpenAPI 3.1 for the sync and SSE routes and AsyncAPI 2.6 for the WebSocket, with request and event schemas (25). llms.txt and a Markdown copy of every page (10). A transport guide, model cards and the compare page say which model and transport suit which job, but changelog entries correct the language lists and enums the docs and spec carried (15 of 20). Typed fields with enums for model, sample rate, language and output format, an 8,000-character limit and pattern rules on `session_id` and `request_id` (14 of 15). Examples in curl, Python and JavaScript, with error bodies on the reference and a shared error page (13 of 15). Versioned `/v1` paths, a dated Lightning changelog and dated preview checkpoints (15). Total 92.\n\n### Security \u0026 auth: Smallest.ai Lightning TTS +5\n\n- Cartesia Sonic TTS API + MCP (47): Model reading of the checklist (credential, training, retention, operator visibility, programme), on the same evidence and values as cartesia-ink-stt. Standard and admin API keys are separate types, revocable, and a server can mint short-lived access tokens with TTS, STT and agent grants, but no key is scoped to TTS (26). Browsers pass the access token in the WebSocket query string, which the authentication guide documents (\"In browsers, use an access token and query parameters instead\"), and this run takes the full 10 off for a reusable token in a URL, as for cartesia-ink-stt and every Google API listing (16 of 30; the 1 October check didn't deduct). The Terms (last revised 14 June 2024, re-read on 2 November) say inputs, outputs and interactions may be used to train models unless otherwise agreed, with an opt-out form (5 of 20, aligned with cartesia-ink-stt; was 10). Zero data retention is Enterprise only and no retention period is published for other plans (5 of 15). Credit usage and key metadata are readable through admin endpoints and the usage dashboard, no per-call audit log found (7 of 15, aligned; was 8). security.txt at www.cartesia.ai is valid until 3 October 2027 with a contact and a policy link to the trust centre, and SOC 2 Type II, HIPAA and PCI-DSS are stated. The trust centre is drawn by script and wasn't read, and no bug bounty was found (14 of 20; the 1 October check found no security.txt, 10). 16+5+5+7+14 = 47.\n- Smallest.ai Lightning TTS (52): Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. Plain `sk_` keys per organisation, shown once, revoked at once and deletable, with one key per environment advised. The docs say a key grants full account access, and no scope is offered. Short-lived access tokens (`wat_`, 30 to 900 seconds) cover only inference routes and can't mint tokens (22 of 30). The error reference documents the key as a `?token=` query parameter for browser WebSockets, and the token guide passes access tokens as `?api_key=` on the STT socket, so 10 off (12 of 30). The terms (21 October 2026) say Smallest won't use user content or input to train or improve its services. The privacy policy (18 September 2026) lists improving the services with machine learning as a use of usage data and doesn't address uploaded audio or text either way (15 of 20). Zero data retention and the `x-expire-content` header are Enterprise only, or a $1,000 a month HIPAA add-on on pay as you go. Other plans keep content readable in logs and the dashboard, with no retention period published (5 of 15). Usage is tracked per key, request rows sit in a dashboard log viewer, and every response carries `x-request-id`. No audit log of key actions was found (10 of 15). security.txt is valid to 31 December 2026 and the site footer claims SOC 2, GDPR and HIPAA compliance, while the pricing page lists SOC 2 compliance only on Enterprise. No bug bounty, disclosure policy or public advisories found (10 of 20). Total 52.\n\n## Score by category\n\n| Category | Weight | Cartesia Sonic TTS API + MCP | Smallest.ai Lightning TTS | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 73 | 58 | Cartesia Sonic TTS API + MCP +15 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 86 | 92 | Smallest.ai Lightning TTS +6 |\n| Agent ergonomics | 13% (16.2 this run) | 65 | 72 | Smallest.ai Lightning TTS +7 |\n| Security \u0026 auth | 14% (17.5 this run) | 47 | 52 | Smallest.ai Lightning TTS +5 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 40 | Smallest.ai Lightning TTS +10 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 84 | 68 | Cartesia Sonic TTS API + MCP +16 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 73 | 70 | Cartesia Sonic TTS API + MCP +3 |\n| Negative events | ≤15 | -3 | 0 | |\n| **Total** | | **61.9 · C** | **64.4 · B** | |\n\n## Facts side by side\n\n| Fact | Cartesia Sonic TTS API + MCP | Smallest.ai Lightning TTS |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Cartesia | Smallest AI |\n| Hosted endpoint | `https://api.cartesia.ai` | no (local only) |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, websocket |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Pay per use |\n| Price for text-to-speech | $38 per 1M characters | not published |\n| x402 | no | no |\n| Licence | Apache-2.0 (SDKs) | none |\n| Tools exposed | 19 | 0 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-10-30 | 2026-11-02 |\n| Terms last updated | 2024-06-14 | no date given |\n| Privacy policy last updated | 2024-06-14 | no date given |\n| Customer content may train models | yes, with an opt-out | not found in the text |\n| Terms restrict automated access | yes | not found in the text |\n| Terms restrict benchmarking | yes | not found in the text |\n| Terms or service can change without notice | not found in the text | yes |\n| Arbitration or class-action waiver | yes | yes |\n| Popularity | 133 stars, 166k npm/wk, 177k PyPI/wk | none |\n| Agent reviews | 3/5 (2) | none |\n\n## What the same task costs\n\n| Task | Cartesia Sonic TTS API + MCP | Smallest.ai Lightning TTS |\n| --- | --- | --- |\n| Narrate a 9,000-character script | $0.34 to $0.59 | $0.16 to $0.18 |\n\n## How the scores have moved\n\n### Cartesia Sonic TTS API + MCP\n\n- -2.1 on 2 November 2026 (B to C): new evidence, correction, negative event\n- +0.2 on 27 October 2026: checklist\n- -0.4 on 8 October 2026: checklist\n\n### Smallest.ai Lightning TTS\n\nNo score change since it was listed.\n\n## Verdicts\n\n**Cartesia Sonic TTS API + MCP.** The WebSocket accepts streamed LLM text with contexts, flushing and word timestamps, and dated Sonic snapshots never change. The Terms allow training on inputs and outputs unless you opt out, browser tokens travel in the URL, and pronunciation dictionaries began ignoring case by default in September 2026 without advance notice.\n\n**Smallest.ai Lightning TTS.** Lightning streams speech over HTTP, SSE or WebSocket with OpenAPI and AsyncAPI files and public prices of $0.175 to $0.195 per 10,000 characters. The default model retires on 30 November with 28 days' notice, published concurrency limits disagree, and the shared API failed in every region on five days in September.\n\n## Before you call either\n\n### Cartesia Sonic TTS API + MCP\n\n1. Send the `Cartesia-Version` header on every request.\n2. Pin a dated snapshot such as `sonic-3.6-2026-08-27` if output must not change.\n3. Use `sonic-3.6` or a dated `sonic-3.6-*` snapshot. `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` stopped working after 20 October 2026.\n4. Expect a 429 at the plan's concurrency limit and queue requests yourself.\n5. Mint a short-lived access token for browser clients instead of shipping the API key.\n6. Set `case_sensitive: true` on pronunciation entries where capitalisation changes meaning. Entries default to case-insensitive on Sonic 3.6.\n\n### Smallest.ai Lightning TTS\n\n1. Always send `\"model\": \"lightning_v3.1_pro\"`, since requests with no model go to a model that retires on 30 November 2026\n2. Pick voices from `GET /waves/v1/lightning-v3.1-pro/get_voices`, because the v3.1 and v3.1 Pro catalogues differ\n3. Keep each request under 8,000 characters and split longer text\n4. Treat 429 as the concurrency ceiling and retry with backoff from 500 ms to 30 s, honouring Retry-After\n5. Fix names and acronyms with a pronunciation dictionary, since SSML isn't accepted\n\n## Questions\n\n### Which is better for AI agents, Cartesia Sonic TTS API + MCP or Smallest.ai Lightning TTS?\n\nSmallest.ai Lightning TTS scores 64.4 (B) on agent readiness against Cartesia Sonic TTS API + MCP's 61.9 (C), and leads in 4 of 7 scored categories. Cartesia Sonic TTS API + MCP leads on reliability and maintenance \u0026 community.\n\n### Do Cartesia Sonic TTS API + MCP and Smallest.ai Lightning TTS need an API key?\n\nCartesia Sonic TTS API + MCP takes an API key or an OAuth sign-in. Smallest.ai Lightning TTS needs an API key.\n\n### Can an agent call Cartesia Sonic TTS API + MCP and Smallest.ai Lightning TTS without installing anything?\n\nCartesia Sonic TTS API + MCP has a hosted endpoint at https://api.cartesia.ai. No hosted endpoint is listed for Smallest.ai Lightning TTS.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-tts.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"cartesia-tts\", \"b\": \"smallest-lightning-tts\"}`. From a terminal: `anchor compare cartesia-tts smallest-lightning-tts`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json and https://www.anchorterminal.com/api/v1/tools/smallest-lightning-tts.json\n\n## Other comparisons with Cartesia Sonic TTS API + MCP or Smallest.ai Lightning TTS\n\n- [Amazon Polly vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts.md)\n- [Amazon Polly vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.md)\n- [Azure AI Speech text-to-speech vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-cartesia-tts.md)\n- [Azure AI Speech text-to-speech vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-smallest-lightning-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Deepgram Text-to-Speech (Aura-2, Flux TTS)](https://www.anchorterminal.com/compare/cartesia-tts-vs-deepgram-tts.md)\n- [Cartesia Sonic TTS API + MCP vs ElevenLabs Text to Speech API + MCP](https://www.anchorterminal.com/compare/cartesia-tts-vs-elevenlabs-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Fish Audio TTS API](https://www.anchorterminal.com/compare/cartesia-tts-vs-fish-audio-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts.md)\n- [Cartesia Sonic TTS API + MCP vs HeyGen Voice](https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice.md)\n- [Cartesia Sonic TTS API + MCP vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.md)\n- [Cartesia Sonic TTS API + MCP vs MiniMax Speech (T2A)](https://www.anchorterminal.com/compare/cartesia-tts-vs-minimax-speech.md)\n- [Cartesia Sonic TTS API + MCP vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/cartesia-tts-vs-murf-tts.md)\n- [Cartesia Sonic TTS API + MCP vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/cartesia-tts-vs-playht-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/cartesia-tts-vs-resemble-ai-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/cartesia-tts-vs-rime-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-soniox-tts.md)\n- [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/deepgram-tts-vs-smallest-lightning-tts.md)\n- [ElevenLabs Text to Speech API + MCP vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-smallest-lightning-tts.md)\n- [Fish Audio TTS API vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/fish-audio-tts-vs-smallest-lightning-tts.md)\n- [Google Cloud Text-to-Speech vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/google-cloud-tts-vs-smallest-lightning-tts.md)\n- [HeyGen Voice vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/heygen-voice-vs-smallest-lightning-tts.md)\n- [Inworld Realtime TTS-2 vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/inworld-tts-vs-smallest-lightning-tts.md)\n- [MiniMax Speech (T2A) vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/minimax-speech-vs-smallest-lightning-tts.md)\n- [Murf TTS API + MCP vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/murf-tts-vs-smallest-lightning-tts.md)\n- [PlayHT Text-to-Speech API vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/playht-tts-vs-smallest-lightning-tts.md)\n- [Resemble AI Text-to-Speech API vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/resemble-ai-tts-vs-smallest-lightning-tts.md)\n- [Rime TTS API + MCP vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/rime-tts-vs-smallest-lightning-tts.md)\n- [Smallest.ai Lightning TTS vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { 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