{ "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", "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" }, { "registry": "pypi", "name": "cartesia" }, { "registry": "pypi", "name": "cartesia-mcp" } ], "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": 15, "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": "2026-09-30", "graded": true, "anchor": { "graded": true, "score": 64, "grade": "B", "agentReady": false, "rank": 428, "ranked": true, "rankOf": 1243, "categoryRank": 7, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 65, "maintenance": 79, "payments": 30, "reliability": 63, "schema": 86, "security": 58, "transparency": 69 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps. Five TTS incidents on the status page between 29 July and 21 August 2026.", "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, Sonic-2 and Sonic Turbo sunset after 2026-10-20" ], "weaknesses": [ "Five TTS incidents on the status page between 29 July and 21 August 2026", "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" ], "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.", "Move off `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` before 2026-10-20.", "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." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "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 } ], "editorialScores": { "ergonomics": 65, "maintenance": 79, "payments": 30, "reliability": 63, "schema": 86, "security": 58, "transparency": 60 }, "provenanceScore": 77, "checked": { "categories": { "ergonomics": "2026-10-01", "maintenance": "2026-10-01", "payments": "2026-10-01", "reliability": "2026-10-01", "schema": "2026-10-01", "security": "2026-10-01", "transparency": "2026-10-01" }, "last": "2026-10-01", "lastMoved": "2026-10-27", "oldest": "2026-10-01", "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": "none", "checked": "2026-09-30", "score": 77 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/cartesia-tts.json", "live": { "slug": "cartesia-tts", "probe": { "target": "https://api.cartesia.ai", "method": "get", "lastAt": "2026-10-31T03:03:52.739382828Z", "lastOk": true, "lastStatus": 200, "lastMs": 49, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 53, "p95ms24h": 107, "samples24h": 249, "samples30d": 7731, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 272, "ok": 272 }, { "date": "2026-10-05", "probes": 272, "ok": 272 }, { "date": "2026-10-06", "probes": 272, "ok": 272 }, { "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": 32, "ok": 32 } ] }, "vendorStatus": { "page": "https://status.cartesia.ai", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-31T03:03:55.384827193Z" }, "versions": [ { "registry": "github", "name": "cartesia-ai/cartesia-python", "version": "v4.2.0", "released": "2026-09-02", "seenAt": "2026-10-30T14:02:44.974355878Z" }, { "registry": "npm", "name": "@cartesia/cartesia-js", "version": "4.2.0", "seenAt": "2026-10-30T14:02:42.712506018Z" }, { "registry": "pypi", "name": "cartesia", "version": "4.2.0", "released": "2026-09-02", "seenAt": "2026-10-30T14:02:42.967420613Z" }, { "registry": "pypi", "name": "cartesia-mcp", "version": "0.28.0", "released": "2026-10-27", "seenAt": "2026-10-30T14:02:43.078211451Z" } ], "githubStars": 136, "npmWeekly": 102548, "pypiWeekly": 257617, "securityTxt": { "url": "https://cartesia.ai/.well-known/security.txt", "state": "valid", "expires": "2027-10-03T00:00:00.000Z", "checkedAt": "2026-10-30T15:37:47.900087666Z" }, "llmsTxt": { "url": "https://docs.cartesia.ai/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-30T15:06:48.854592042Z" }, "domain": { "domain": "cartesia.ai", "registered": "2023-05-10", "source": "https://rdap.identitydigital.services/rdap/domain/cartesia.ai", "checkedAt": "2026-10-25T13:52:38.570004534Z" }, "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": "2026-10-30T05:32:49.194076013Z", "changedAt": "2026-10-30T05:32:49.194076013Z", "fingerprint": "d9e3b8608877" }, { "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": "2026-10-26T07:16:53.518095553Z", "stars": 135, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-23T17:44:26Z", "openIssues": 1, "openPRs": 6, "issuesOpened90d": 1, "issuesClosed90d": 1, "prsMerged90d": 5, "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": "2026-10-31T03:03:52.739382828Z" } }, "answer": "Cartesia Sonic TTS API + MCP scores 64 (B) on agent readiness against Inworld Realtime TTS-2's 58.3 (C), and leads in 4 of 7 scored categories. Inworld Realtime TTS-2 leads on payments \u0026 pricing.", "b": { "slug": "inworld-tts", "name": "Inworld Realtime TTS-2", "vendor": "Inworld AI", "vendorUrl": "https://inworld.ai", "kind": "model", "category": "text-to-speech", "summary": "Inworld's hosted text-to-speech models, `inworld-tts-2` and `inworld-tts-2-flash`, over REST, HTTP streaming, WebSocket, async jobs and an OpenAI-compatible endpoint. TTS-2 takes bracketed steering, and an opt-in Reasoning step writes the delivery direction itself.", "url": "https://www.anchorterminal.com/tools/inworld-tts", "markdownUrl": "https://www.anchorterminal.com/tools/inworld-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/inworld-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/inworld-tts.json", "license": "Proprietary service under Inworld's Terms of Service. The Node.js SDK `@inworld/tts` and the CLI `@inworld/cli` are MIT on npm", "transports": [ "http", "websocket" ], "remoteUrl": "https://api.inworld.ai", "packages": [ { "registry": "npm", "name": "@inworld/tts" }, { "registry": "pypi", "name": "inworld-tts" }, { "registry": "npm", "name": "@inworld/cli" } ], "auth": "api-key", "authNotes": "Every call sends `Authorization: Basic` with the Base64 `key_id:secret` credential copied from the Portal or printed by the CLI. Keys belong to a workspace, are deleted to revoke, and have write toggles only for the Voice and Router APIs, so no key is limited to TTS. Browser and mobile clients use single-use tokens minted server-side, valid 15 minutes by default.", "pricing": "freemium", "pricingNotes": "TTS-2 costs $25 per million characters on the free On-Demand plan, falling to $20, $17.50, $15 and $12.50 on the $25, $100, $300 and $1,500 monthly plans, and from $5 on Enterprise. TTS-2 Flash runs $15 down to $7. On-Demand includes up to 70 minutes of TTS with no card. Steering tags count as characters, while `synthesisContext` and `reasoningContext` aren't billed. Batch costs 20 per cent less (checked 2026-10-30).", "priceSummary": "$25 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in llms.txt, the TTS docs, the billing page or the pricing page (checked 2026-10-30). Usage is drawn from prepaid plan credits, card top-ups of at least $10 or auto-reload.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 3632, "pypiWeekly": null, "asOf": "2026-10-30" }, "docsUrl": "https://docs.inworld.ai/tts/tts", "llmsTxt": "https://docs.inworld.ai/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.ssml", "speech.languages", "speech.batch", "voice.clone", "voice.design" ], "tags": [ "hosted", "official", "closed-source", "freemium", "free-tier", "no-card", "llms-txt", "streaming", "openai-compatible", "reasoning", "multilingual", "async-jobs", "batch", "typescript", "python", "cli", "mcp", "status-page", "soc2", "enterprise" ], "lastRelease": "2026-10-28", "graded": true, "anchor": { "graded": true, "score": 58.3, "grade": "C", "agentReady": false, "rank": 687, "ranked": true, "rankOf": 1243, "categoryRank": 10, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 68, "maintenance": 68, "payments": 40, "reliability": 62, "schema": 60, "security": 61, "transparency": 63 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-30" }, "negative": -2, "negativeNotes": [ "30 October 2026. Inworld's Realtime TTS-2 page shows Realtime TTS-2 as #1 for voice quality on the Artificial Analysis Speech Arena and says the ranks come from the live arena, not hardcoded. Artificial Analysis's provider-voice leaderboard on the same day put Realtime TTS-2 8th (Elo 1,267) behind Eleven v4 Turbo (1,336). The page also says the table was verified in May 2026. The deduction lapses if the page is corrected or the rank returns. Sources: https://inworld.ai/blog/realtime-tts-2 and https://artificialanalysis.ai/text-to-speech/leaderboard/provider-voice (-2)" ], "verdict": "TTS-2 takes bracketed steering, and opt-in Reasoning writes a delivery direction from the text and up to 600 characters of context, returning it in the response. Per-character prices are public and the free plan needs no card. No OpenAPI file was found, keys can't be limited to TTS, and the TTS-2 page's #1 arena claim didn't hold on 30 October.", "bestFor": "Agents that generate replies or stories at runtime and want delivery chosen from context without writing tags, and for per-message or pre-generated audio.", "strengths": [ "Reasoning returns the direction it applied as `reasoningInstruction`, so an agent can log it and reuse it as an inline tag", "Per-character prices are public, from $25 per million characters for TTS-2 on the free plan to $12.50 on Growth", "REST, HTTP streaming, WebSocket, async jobs and an OpenAI-compatible `/v1/audio/speech` endpoint", "llms.txt, Markdown twins of every page and a keyless docs MCP server at docs.inworld.ai/mcp", "Single-use client tokens, 15 minutes by default, keep the API key off browsers and phones" ], "weaknesses": [ "No OpenAPI or other machine-readable contract was found for the TTS API", "API keys can't be limited to TTS. Write toggles cover only the Voice and Router APIs", "The 28 October model update replaced `inworld-tts-2` in place, with no dated snapshot to pin", "Zero data retention is Enterprise only or a Growth add-on, and the SLA is Enterprise only", "The TTS-2 page claims #1 on the Artificial Analysis Speech Arena, which ranked it 8th on 30 October 2026" ], "agentNotes": [ "Send the copied Base64 credential as-is in `Authorization: Basic`. Don't encode it again.", "Set `modelId` explicitly, because SDK defaults may name deprecated models.", "Keep text under 2,000 UTF-16 units on `/tts/v1/voice` and 4,000 on `voice:stream`, or use an async job.", "Turn on Reasoning with `synthesisContext.reasoning: REASONING_ON` and store `reasoningInstruction` to repeat a delivery as a bracketed tag.", "On 429 or error code 8, back off exponentially with jitter. No Retry-After header is documented." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 58.3 } ], "editorialScores": { "ergonomics": 68, "maintenance": 68, "payments": 40, "reliability": 62, "schema": 60, "security": 61, "transparency": 51 }, "provenanceScore": 75, "checked": { "categories": { "ergonomics": "2026-10-30", "maintenance": "2026-10-30", "payments": "2026-10-30", "reliability": "2026-10-30", "schema": "2026-10-30", "security": "2026-10-30", "transparency": "2026-10-30" }, "last": "2026-10-30", "oldest": "2026-10-30", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install @inworld/tts", "http": "curl -X POST https://api.inworld.ai/tts/v1/voice -H \"Authorization: Basic $INWORLD_API_KEY\" -H 'Content-Type: application/json' -d '{\"text\": \"We made it. I honestly did not think we would.\", \"voiceId\": \"Dennis\", \"modelId\": \"inworld-tts-2\", \"synthesisContext\": {\"reasoning\": \"REASONING_ON\"}}'", "claudeCode": "claude mcp add inworld -- inworld mcp" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/inworld-tts" }, "area": "voice", "unitPrices": [ { "item": "Realtime TTS-2, On-Demand (free plan, pay as you go)", "unit": "1m-chars", "usd": 25, "note": "pricing page, checked 30 October 2026" }, { "item": "Realtime TTS-2 on Growth", "unit": "1m-chars", "usd": 12.5, "note": "$20 on Creator, $17.50 on Builder, $15 on Developer, from $5 on Enterprise" }, { "item": "Realtime TTS-2 Flash, On-Demand", "unit": "1m-chars", "usd": 15, "note": "falls to $7 on Growth" }, { "item": "Creator plan", "unit": "month", "usd": 25, "note": "$25 in credits a month" }, { "item": "Developer plan", "unit": "month", "usd": 300, "note": "$300 in credits a month, priority email support" } ], "provenance": { "legalEntity": "Theai, Inc. dba Inworld AI", "domain": "inworld.ai", "domainRegistered": "", "endpointOnVendorDomain": true, "terms": "https://inworld.ai/terms", "privacy": "https://inworld.ai/privacy", "statusPage": "https://status.inworld.ai", "changelog": "https://docs.inworld.ai/release-notes/tts", "securityTxt": "none", "checked": "2026-10-30", "notes": [ "The Terms of Service (effective 11 June 2025) are an agreement with Theai, Inc. dba Inworld AI under California law, with courts in Santa Clara. The Privacy Notice (last updated 18 January 2026) names Theai, Inc.", "inworld.ai/.well-known/security.txt returns 404. The security page links a vulnerability report form.", "status.inworld.ai runs the open-source issue-status app, which draws incidents from GitHub issues in inworld-ai/inworld-issue-status. Its history wasn't read, because GitHub's robots.txt couldn't be read from our environment.", "inworld.ai's robots.txt allows Claude agents on the paths read and sets `Content-Signal: ai-train=no, search=yes, ai-input=no`. docs.inworld.ai has no such signal.", "The domain's registration date wasn't established, because the RDAP lookup failed.", "firstReleased is the TTS-2 launch entry in the TTS release notes, 5 May 2026. Inworld's TTS-2 page dates general availability to 31 August 2026, and Reasoning shipped on 28 October 2026." ], "score": 75 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/inworld-tts.json", "live": { "slug": "inworld-tts", "probe": { "target": "https://api.inworld.ai", "method": "get", "lastAt": "2026-10-31T03:04:02.49858712Z", "lastOk": true, "lastStatus": 200, "lastMs": 146, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 158, "p95ms24h": 339, "samples24h": 16, "samples30d": 16, "days": [ { "date": "2026-10-31", "probes": 16, "ok": 16 } ] }, "vendorStatus": { "page": "https://status.inworld.ai", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-31T03:04:35.255164605Z" }, "updatedAt": "2026-10-31T03:04:35.255164605Z" } }, "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "Cartesia", "b": "Inworld AI", "name": "Vendor" }, { "a": "https://api.cartesia.ai", "b": "https://api.inworld.ai", "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": "Freemium", "name": "Pricing" }, { "a": "$38 per 1M characters", "b": "$12.50 per 1M characters", "name": "Price for text-to-speech" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Apache-2.0 (SDKs)", "b": "Proprietary service under Inworld's Terms of Service. The Node.js SDK `@inworld/tts` and the CLI `@inworld/cli` are MIT on npm", "name": "Licence" }, { "a": "15", "b": "none", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-09-30", "b": "2026-10-28", "name": "Last release" }, { "a": "2024-06-14", "b": "2025-06-11", "name": "Terms last updated" }, { "a": "2024-06-14", "b": "2026-01-18", "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": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "yes", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "133 stars, 166k npm/wk, 177k PyPI/wk", "b": "3.6k npm/wk", "name": "Popularity" }, { "a": "3/5 (2)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Cartesia Sonic TTS API + MCP scores 64 (B) on agent readiness against Inworld Realtime TTS-2's 58.3 (C), and leads in 4 of 7 scored categories. Inworld Realtime TTS-2 leads on payments \u0026 pricing.", "question": "Which is better for AI agents, Cartesia Sonic TTS API + MCP or Inworld Realtime TTS-2?" }, { "answer": "Inworld Realtime TTS-2, at $12.50 per 1M characters against $38 per 1M characters for Cartesia Sonic TTS API + MCP. These are the vendors' published prices for the job.", "question": "Which is cheaper for text-to-speech, Cartesia Sonic TTS API + MCP or Inworld Realtime TTS-2?" }, { "answer": "Cartesia Sonic TTS API + MCP takes an API key or an OAuth sign-in. Inworld Realtime TTS-2 needs an API key.", "question": "Do Cartesia Sonic TTS API + MCP and Inworld Realtime TTS-2 need an API key?" }, { "answer": "Yes. Cartesia Sonic TTS API + MCP has a hosted endpoint at https://api.cartesia.ai and Inworld Realtime TTS-2 at https://api.inworld.ai.", "question": "Can an agent call Cartesia Sonic TTS API + MCP and Inworld Realtime TTS-2 without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 86 against 60", "Maintenance \u0026 community, 79 against 68", "Transparency \u0026 trust, 69 against 63" ], "also": [ "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": "Five TTS incidents on the status page between 29 July and 21 August 2026" }, { "aheadOn": [ "Payments \u0026 pricing, 40 against 30" ], "also": [ "Cheaper for text-to-speech, $12.50 against $38 per 1M characters", "Free to start without a card" ], "goodFor": "Agents that generate replies or stories at runtime and want delivery chosen from context without writing tags, and for per-message or pre-generated audio.", "slug": "inworld-tts", "watchFor": "No OpenAPI or other machine-readable contract was found for the TTS API" } ], "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-inworld-tts.json", "title": "Amazon Polly vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-inworld-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-inworld-tts.json", "title": "Azure AI Speech text-to-speech vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-inworld-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-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-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-inworld-tts.json", "title": "Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/deepgram-tts-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-inworld-tts.json", "title": "ElevenLabs Text to Speech API + MCP vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-inworld-tts.json", "title": "Fish Audio TTS API vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts.json", "title": "HeyGen Voice vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-murf-tts.json", "title": "Inworld Realtime TTS-2 vs Murf TTS API + MCP", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-murf-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-playht-tts.json", "title": "Inworld Realtime TTS-2 vs PlayHT Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-playht-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-resemble-ai-tts.json", "title": "Inworld Realtime TTS-2 vs Resemble AI Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-resemble-ai-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-rime-tts.json", "title": "Inworld Realtime TTS-2 vs Rime TTS API + MCP", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-rime-tts" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-soniox-tts.json", "title": "Inworld Realtime TTS-2 vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-soniox-tts" } ], "scores": [ { "by": 1, "cartesia-tts": 63, "edge": "cartesia-tts", "inworld-tts": 62, "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 26, "cartesia-tts": 86, "edge": "cartesia-tts", "inworld-tts": 60, "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 3, "cartesia-tts": 65, "edge": "inworld-tts", "inworld-tts": 68, "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "by": 3, "cartesia-tts": 58, "edge": "inworld-tts", "inworld-tts": 61, "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "by": 10, "cartesia-tts": 30, "edge": "inworld-tts", "inworld-tts": 40, "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 11, "cartesia-tts": 79, "edge": "cartesia-tts", "inworld-tts": 68, "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 6, "cartesia-tts": 69, "edge": "cartesia-tts", "inworld-tts": 63, "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "Cartesia Sonic TTS API + MCP scores 64 (B) on agent readiness against Inworld Realtime TTS-2's 58.3 (C), and leads in 4 of 7 scored categories. Inworld Realtime TTS-2 leads on payments \u0026 pricing. Both do text-to-speech. Inworld Realtime TTS-2 is cheaper for text-to-speech, $12.50 against $38 per 1M characters.", "tutorials": [], "verdicts": { "cartesia-tts": "WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps. Five TTS incidents on the status page between 29 July and 21 August 2026.", "inworld-tts": "TTS-2 takes bracketed steering, and opt-in Reasoning writes a delivery direction from the text and up to 600 characters of context, returning it in the response. Per-character prices are public and the free plan needs no card. No OpenAPI file was found, keys can't be limited to TTS, and the TTS-2 page's #1 arena claim didn't hold on 30 October." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts", "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.min.md" }, "markdown": "Cartesia Sonic TTS API + MCP scores 64 (B) on agent readiness against Inworld Realtime TTS-2's 58.3 (C), and leads in 4 of 7 scored categories. Inworld Realtime TTS-2 leads on payments \u0026 pricing. Both do text-to-speech. Inworld Realtime TTS-2 is cheaper for text-to-speech, $12.50 against $38 per 1M characters.\n\n- Cartesia Sonic TTS API + MCP: grade B, 64/100, rank #428 of 1243. Markdown https://www.anchorterminal.com/tools/cartesia-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json\n- Inworld Realtime TTS-2: grade C, 58.3/100, rank #687 of 1243. Markdown https://www.anchorterminal.com/tools/inworld-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/inworld-tts.json\n- Best text-to-speech APIs for AI agents: https://www.anchorterminal.com/best/text-to-speech/index.md\n- All 106 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 (B)\n\nGood for: Real-time voice agents that stream LLM output straight into speech and need stable, pinnable models.\n\nAhead on:\n- Schema \u0026 documentation, 86 against 60\n- Maintenance \u0026 community, 79 against 68\n- Transparency \u0026 trust, 69 against 63\n\nAlso in its favour:\n- Runs on your own machine\n\nWatch for: Five TTS incidents on the status page between 29 July and 21 August 2026\n\n### Inworld Realtime TTS-2 (C)\n\nGood for: Agents that generate replies or stories at runtime and want delivery chosen from context without writing tags, and for per-message or pre-generated audio.\n\nAhead on:\n- Payments \u0026 pricing, 40 against 30\n\nAlso in its favour:\n- Cheaper for text-to-speech, $12.50 against $38 per 1M characters\n- Free to start without a card\n\nWatch for: No OpenAPI or other machine-readable contract was found for the TTS API\n\n\n## Score by category\n\n| Category | Weight | Cartesia Sonic TTS API + MCP | Inworld Realtime TTS-2 | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 63 | 62 | Cartesia Sonic TTS API + MCP +1 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 86 | 60 | Cartesia Sonic TTS API + MCP +26 |\n| Agent ergonomics | 13% (16.2 this run) | 65 | 68 | Inworld Realtime TTS-2 +3 |\n| Security \u0026 auth | 14% (17.5 this run) | 58 | 61 | Inworld Realtime TTS-2 +3 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 40 | Inworld Realtime TTS-2 +10 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 79 | 68 | Cartesia Sonic TTS API + MCP +11 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 69 | 63 | Cartesia Sonic TTS API + MCP +6 |\n| Negative events | ≤15 | 0 | -2 | |\n| **Total** | | **64 · B** | **58.3 · C** | |\n\n## Facts side by side\n\n| Fact | Cartesia Sonic TTS API + MCP | Inworld Realtime TTS-2 |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Cartesia | Inworld AI |\n| Hosted endpoint | `https://api.cartesia.ai` | `https://api.inworld.ai` |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, websocket |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Freemium |\n| Price for text-to-speech | $38 per 1M characters | $12.50 per 1M characters |\n| x402 | no | no |\n| Licence | Apache-2.0 (SDKs) | Proprietary service under Inworld's Terms of Service. The Node.js SDK `@inworld/tts` and the CLI `@inworld/cli` are MIT on npm |\n| Tools exposed | 15 | none |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-09-30 | 2026-10-28 |\n| Terms last updated | 2024-06-14 | 2025-06-11 |\n| Privacy policy last updated | 2024-06-14 | 2026-01-18 |\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 | not found in the text |\n| Arbitration or class-action waiver | yes | not found in the text |\n| Popularity | 133 stars, 166k npm/wk, 177k PyPI/wk | 3.6k npm/wk |\n| Agent reviews | 3/5 (2) | none |\n\n## Verdicts\n\n**Cartesia Sonic TTS API + MCP.** WebSocket input accepts streamed LLM text with contexts, flushing and word timestamps. Five TTS incidents on the status page between 29 July and 21 August 2026.\n\n**Inworld Realtime TTS-2.** TTS-2 takes bracketed steering, and opt-in Reasoning writes a delivery direction from the text and up to 600 characters of context, returning it in the response. Per-character prices are public and the free plan needs no card. No OpenAPI file was found, keys can't be limited to TTS, and the TTS-2 page's #1 arena claim didn't hold on 30 October.\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. Move off `sonic-2`, `sonic-turbo` and `sonic-3-2025-10-27` before 2026-10-20.\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.\n\n### Inworld Realtime TTS-2\n\n1. Send the copied Base64 credential as-is in `Authorization: Basic`. Don't encode it again.\n2. Set `modelId` explicitly, because SDK defaults may name deprecated models.\n3. Keep text under 2,000 UTF-16 units on `/tts/v1/voice` and 4,000 on `voice:stream`, or use an async job.\n4. Turn on Reasoning with `synthesisContext.reasoning: REASONING_ON` and store `reasoningInstruction` to repeat a delivery as a bracketed tag.\n5. On 429 or error code 8, back off exponentially with jitter. No Retry-After header is documented.\n\n## Questions\n\n### Which is better for AI agents, Cartesia Sonic TTS API + MCP or Inworld Realtime TTS-2?\n\nCartesia Sonic TTS API + MCP scores 64 (B) on agent readiness against Inworld Realtime TTS-2's 58.3 (C), and leads in 4 of 7 scored categories. Inworld Realtime TTS-2 leads on payments \u0026 pricing.\n\n### Which is cheaper for text-to-speech, Cartesia Sonic TTS API + MCP or Inworld Realtime TTS-2?\n\nInworld Realtime TTS-2, at $12.50 per 1M characters against $38 per 1M characters for Cartesia Sonic TTS API + MCP. These are the vendors' published prices for the job.\n\n### Do Cartesia Sonic TTS API + MCP and Inworld Realtime TTS-2 need an API key?\n\nCartesia Sonic TTS API + MCP takes an API key or an OAuth sign-in. Inworld Realtime TTS-2 needs an API key.\n\n### Can an agent call Cartesia Sonic TTS API + MCP and Inworld Realtime TTS-2 without installing anything?\n\nYes. Cartesia Sonic TTS API + MCP has a hosted endpoint at https://api.cartesia.ai and Inworld Realtime TTS-2 at https://api.inworld.ai.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"cartesia-tts\", \"b\": \"inworld-tts\"}`. From a terminal: `anchor compare cartesia-tts inworld-tts`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/cartesia-tts.json and https://www.anchorterminal.com/api/v1/tools/inworld-tts.json\n\n## Other comparisons with Cartesia Sonic TTS API + MCP or Inworld Realtime TTS-2\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 Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/amazon-polly-vs-inworld-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 Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-inworld-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 HeyGen Voice](https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice.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 Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/deepgram-tts-vs-inworld-tts.md)\n- [ElevenLabs Text to Speech API + MCP vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-inworld-tts.md)\n- [Fish Audio TTS API vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/fish-audio-tts-vs-inworld-tts.md)\n- [HeyGen Voice vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts.md)\n- [Inworld Realtime TTS-2 vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/inworld-tts-vs-murf-tts.md)\n- [Inworld Realtime TTS-2 vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/inworld-tts-vs-playht-tts.md)\n- [Inworld Realtime TTS-2 vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/inworld-tts-vs-resemble-ai-tts.md)\n- [Inworld Realtime TTS-2 vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/inworld-tts-vs-rime-tts.md)\n- [Inworld Realtime TTS-2 vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/inworld-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": "2026-10-31", "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": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Cartesia Sonic TTS API + MCP vs Inworld Realtime TTS-2", "url": "" } ], "description": "Cartesia Sonic TTS scores 64 (B) to Inworld Realtime TTS-2's 58.3 (C) for text-to-speech. Inworld Realtime TTS-2 is cheaper for text-to-speech, $12.50 against $38 per 1M characters. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Cartesia Sonic TTS API + MCP B 64", "Inworld Realtime TTS-2 C 58.3", "scores" ], "h1": "Cartesia Sonic TTS API + MCP vs Inworld Realtime TTS-2", "image": "https://www.anchorterminal.com/assets/og/compare-cartesia-tts-vs-inworld-tts.png", "path": "/compare/cartesia-tts-vs-inworld-tts", "published": "2026-10-01", "section": "tools", "title": "Cartesia Sonic TTS vs Inworld Realtime TTS-2 for AI agents (2026)", "toc": null, "updated": "2026-10-31", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-inworld-tts" }, "tokens": { "markdown": 2750, "slim": 780 }, "version": 1 }