{ "data": { "a": { "slug": "amazon-polly", "name": "Amazon Polly", "vendor": "Amazon Web Services", "vendorUrl": "https://aws.amazon.com/polly/", "kind": "model", "category": "text-to-speech", "summary": "AWS's speech synthesis API with four engines (standard, neural, long-form and generative) and 116 voices in 42 languages and variants.", "url": "https://www.anchorterminal.com/tools/amazon-polly", "markdownUrl": "https://www.anchorterminal.com/tools/amazon-polly.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/amazon-polly.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/amazon-polly.json", "dns": "amazon-polly.grade.anchorterminal.com", "transports": [ "http" ], "remoteUrl": "https://polly.us-east-1.amazonaws.com/v1", "packages": [ { "registry": "npm", "name": "@aws-sdk/client-polly" }, { "registry": "pypi", "name": "boto3" } ], "auth": "api-key", "authNotes": "AWS Signature Version 4 with IAM access keys or a role. Regional endpoints `polly.\u003cregion\u003e.amazonaws.com`.", "pricing": "usage", "pricingNotes": "$4 per 1M characters for standard voices, $16 neural, $30 generative and $100 long-form. SSML tags aren't billed. Accounts opened before 2025-07-15 get 5M standard characters a month (and 1M neural for 12 months). Newer accounts get up to $200 in Free Tier credits on a free plan of up to 6 months. AWS says most new customers can sign up without a payment method, and that it might request one and hold USD $1 to verify (https://aws.amazon.com/polly/pricing/, https://aws.amazon.com/free/free-tier-faqs/).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No machine payment. Billing runs through a cloud account with a card or invoice.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 743201, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://docs.aws.amazon.com/polly/latest/dg/what-is.html", "llmsTxt": "https://docs.aws.amazon.com/polly/latest/dg/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.ssml", "speech.languages" ], "tags": [ "hosted", "closed-source", "python", "typescript", "enterprise", "streaming", "batch", "async-jobs", "llms-txt", "free-tier", "no-card" ], "lastRelease": "2026-10-22", "graded": true, "anchor": { "graded": true, "score": 75.4, "grade": "BB", "agentReady": true, "rank": 61, "ranked": true, "rankOf": 1510, "categoryRank": 2, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 82, "maintenance": 70, "payments": 30, "reliability": 80, "schema": 90, "security": 83, "transparency": 80 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "high", "date": "2026-11-01" }, "negative": 0, "verdict": "IAM policies scope access per action and resource, and CloudTrail logs each call. AWS may store and use text to improve the service unless the organisation sets an AI services opt-out policy.", "bestFor": "Operators already on AWS who want predictable, cheap speech for prompts, notifications and IVR, or generative voices with bidirectional streaming.", "strengths": [ "IAM policies scope access per action and resource, and CloudTrail logs each call", "Quotas published per operation and engine, with backoff and jitter guidance for throttling", "Covered by the Amazon Machine Learning Language SLA, and in AWS's SOC 1, 2 and 3 scope", "Standard voices at $4 and neural at $16 per 1M characters", "Ten generative voices added on 22 October 2026, with typed exceptions per action and a public service model in every AWS SDK" ], "weaknesses": [ "AWS may store and use text to improve the service, possibly outside the Region, unless the organisation sets an AI services opt-out policy", "The monthly free characters only apply to accounts opened before 2025-07-15, and AWS may still ask new accounts for a payment method", "Listed in AWS's open me-south-1 (Bahrain) disruption, where AWS said on 15 September 2026 that Region-only data can't be restored", "Neural, long-form and generative synthesis is limited to 8 requests a second by default", "Generative voices support only part of SSML" ], "agentNotes": [ "Keep `SynthesizeSpeech` under 3,000 billed characters, or use `StartSpeechSynthesisTask` for longer text.", "Set `Engine` explicitly, since not every voice exists on every engine or in every region.", "Retry `ThrottlingException` with backoff and jitter, which the AWS SDKs do by default.", "Check the generative SSML tag list before porting neural SSML.", "Ask for `OutputFormat` `json` with speech marks when you need word timings." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 8, "avgRating": 4, "history": [ { "basis": "public evidence", "confidence": "high", "grade": "BB", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 75.4 } ], "editorialScores": { "ergonomics": 82, "maintenance": 70, "payments": 30, "reliability": 80, "schema": 90, "security": 83, "transparency": 65 }, "provenanceScore": 94, "checked": { "categories": { "ergonomics": "2026-11-01", "maintenance": "2026-11-01", "payments": "2026-11-01", "reliability": "2026-11-01", "schema": "2026-11-01", "security": "2026-11-01", "transparency": "2026-11-01" }, "last": "2026-11-01", "lastMoved": "2026-11-01", "oldest": "2026-11-01", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "pip install boto3 # or: npm i @aws-sdk/client-polly", "http": "curl -X POST \"https://polly.us-east-1.amazonaws.com/v1/speech\" \\\n --aws-sigv4 \"aws:amz:us-east-1:polly\" --user \"$AWS_ACCESS_KEY_ID:$AWS_SECRET_ACCESS_KEY\" \\\n -H \"content-type: application/json\" -o speech.mp3 \\\n -d '{\"Engine\":\"neural\",\"VoiceId\":\"Joanna\",\"OutputFormat\":\"mp3\",\"Text\":\"Your table is booked for seven.\"}'" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/amazon-polly" }, "sameCompany": [ "amazon-bedrock", "amazon-nova-embeddings", "amazon-bedrock-guardrails", "amazon-transcribe", "amazon-nova-sonic", "agentcore-memory", "agentcore-identity", "aws-secrets-manager", "agentcore-web-search", "aws-mcp-servers", "amazon-ses", "amazon-location", "amazon-translate", "amazon-ads-api", "amazon-creators-api" ], "area": "voice", "unitPrices": [ { "item": "Standard voices", "unit": "1m-chars", "usd": 4 }, { "item": "Neural voices", "unit": "1m-chars", "usd": 16 }, { "item": "Generative voices", "unit": "1m-chars", "usd": 30 }, { "item": "Long-form voices", "unit": "1m-chars", "usd": 100 } ], "provenance": { "legalEntity": "Amazon Web Services, Inc.", "domain": "amazon.com", "domainRegistered": "1994-11-01", "domainNote": "The endpoints are on amazonaws.com (registered 2005-08-18) and api.aws, both AWS domains. The security.txt on aws.amazon.com is valid, with Expires 2027-10-16. The Service Terms show Last Updated 30 October 2026.", "endpointOnVendorDomain": true, "terms": "https://aws.amazon.com/service-terms/", "privacy": "https://aws.amazon.com/privacy/", "statusPage": "https://health.aws.amazon.com/health/status", "changelog": "https://docs.aws.amazon.com/polly/latest/dg/doc-history.html", "securityTxt": "valid", "checked": "2026-11-01", "score": 94 }, "requirements": { "setupChecked": true, "complianceChecked": true, "card": "paid-only", "freeTier": true, "minutes": 15, "credential": "cloud-iam", "hosting": [ "US", "CA", "EU", "UK", "APAC" ], "euResidency": "yes", "trainsOnData": "opt-out", "zeroRetention": "unknown", "certifications": [ "SOC 2 Type II", "ISO 27001", "ISO 27701", "CSA STAR", "HIPAA (BAA available)", "FedRAMP", "GDPR" ], "dpa": true, "selfHost": "no" }, "pageJsonUrl": "https://www.anchorterminal.com/tools/amazon-polly.json", "live": { "slug": "amazon-polly", "probe": { "target": "https://polly.us-east-1.amazonaws.com/v1", "method": "get", "lastAt": "2026-11-07T19:21:51.732963932Z", "lastOk": true, "lastStatus": 404, "lastMs": 309, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 270, "p95ms24h": 352, "samples24h": 238, "samples30d": 7920, "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": 197, "ok": 197 } ] }, "vendorStatus": { "page": "https://health.aws.amazon.com/health/status", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-06T09:56:18.060105872Z" }, "versions": [ { "registry": "npm", "name": "@aws-sdk/client-polly", "version": "3.1164.0", "seenAt": "2026-11-06T23:05:37.879864292Z" }, { "registry": "pypi", "name": "boto3", "version": "1.43.126", "released": "2026-11-06", "seenAt": "2026-11-06T23:05:38.735488567Z" } ], "npmWeekly": 961731, "pypiWeekly": 637851852, "securityTxt": { "url": "https://amazon.com/.well-known/security.txt", "state": "valid", "checkedAt": "2026-11-07T16:00:18.354437696Z" }, "llmsTxt": { "url": "https://docs.aws.amazon.com/polly/latest/dg/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:31:27.825536777Z" }, "domain": { "domain": "amazon.com", "registered": "1994-11-01", "source": "https://rdap.verisign.com/com/v1/domain/amazon.com", "checkedAt": "2026-11-01T14:09:08.477101866Z" }, "pages": [ { "url": "https://docs.aws.amazon.com/polly/latest/dg/doc-history.html", "kind": "changelog", "status": 304, "checkedAt": "2026-11-07T14:05:22.269673755Z", "changedAt": "2026-10-23T01:44:48.858838718Z", "fingerprint": "bed69613e7fb" }, { "url": "https://aws.amazon.com/polly/pricing/", "kind": "pricing", "status": 304, "checkedAt": "2026-11-07T14:00:04.62994204Z", "changedAt": "2026-11-06T13:22:50.468138668Z", "fingerprint": "94e7335aa3b2" }, { "url": "https://aws.amazon.com/privacy/", "kind": "privacy", "status": 304, "checkedAt": "2026-10-01T13:11:21.687931657Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "6ebd6be5615f" }, { "url": "https://aws.amazon.com/service-terms/", "kind": "terms", "status": 200, "checkedAt": "2026-10-01T13:11:23.703347826Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "c2276020bd07" } ], "updatedAt": "2026-11-07T19:21:51.732963932Z" } }, "answer": "Amazon Polly scores 75.4 (BB) on agent readiness against Smallest.ai Lightning TTS's 64.4 (B), and leads in 5 of 7 scored categories. Smallest.ai Lightning TTS leads on payments \u0026 pricing.", "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": 471, "ranked": true, "rankOf": 1510, "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": 31, "category": "security", "leads": "amazon-polly", "name": "Security \u0026 auth", "reasons": { "a": "Model reading of the checklist, with training and retention in place of least-privilege and injection lines. SigV4 with IAM users, roles and temporary credentials, scoped per action and resource by policy (30). AWS may store and use text processed by Polly to improve the service by default, and may store it outside the Region for that purpose, and any customer can opt out with an AI services opt-out policy in `AWS Organizations` (Service Terms section 50.3, Last Updated 30 October 2026, re-read on 1 November) (10 of 20). Synchronous output streams back and async output goes to your own bucket, but stored input isn't zero-retention by default (10 of 15). CloudTrail logs API calls per caller (15). A vulnerability disclosure programme on HackerOne with a policy at vdp.aws.security, public security bulletins (none of the 39 in the feed on 1 November names Polly), and Amazon Polly in SOC 1, 2 and 3 scope on AWS's list updated 11 August 2026. The security.txt on aws.amazon.com is valid to 2027-10-16 and points to the VDP. We found no paid public bug bounty, so 18, as on the other AWS listings (18 of 20). 30 + 10 + 10 + 15 + 18 = 83.", "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": 83, "b": 52 } }, { "by": 22, "category": "reliability", "leads": "amazon-polly", "name": "Reliability", "reasons": { "a": "AWS Health Dashboard with per-service, per-region history and RSS feeds (20). The Polly us-east-1 feed carried no events on 1 November 2026 (built 00:39 PDT), and the dashboard history file read that day has no event naming Polly other than the Middle East (Bahrain) me-south-1 multi-service event open since 2 March 2026, where Amazon Polly sits at the same disruption status S3 carries in the UAE event. On 15 September 2026, inside the 90-day window, AWS said it can't restore resources and data hosted only in that Region, and no update has followed. The newest event in the file is API Gateway in us-west-2 on 30 October, not Polly. One major event, read as the S3 and Secrets Manager re-checks read the UAE one (10). The 15 September update leaves the window after 14 December. Quotas published per operation and engine, 80 requests a second for standard `SynthesizeSpeech` and 8 for neural, long-form and generative, with burst and concurrency figures, re-read on 1 November (15). Throttled calls return HTTP 400 with `ThrottlingException` and the quotas page says to retry with backoff and jitter, which the SDKs do by default. Synthesis has no side effects, so a retry is safe (15). SLA under the Amazon Machine Learning Language agreement (Last Updated 28 November 2023), which names Amazon Polly, re-read on 1 November (10). GA (10). 20 + 10 + 15 + 15 + 10 + 10 = 80.", "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": 80, "b": 58 } }, { "by": 10, "category": "ergonomics", "leads": "amazon-polly", "name": "Agent ergonomics", "reasons": { "a": "API reading of the checklist. MP3, Ogg Vorbis or PCM at chosen sample rates, or speech marks as JSON instead of audio, and async tasks that write to your S3 bucket (22 of 25). `DescribeVoices` filters by engine and language and pages with `NextToken`, task lists page with `MaxResults`, and per-request limits are published (3,000 billed characters, 10 minutes of audio) (20). Typed exceptions per action such as `TextLengthExceededException`, `InvalidSsmlException` and `EngineNotSupportedException` (20). Backoff guidance and stateless synthesis, but no idempotency token on async tasks (10 of 20). Three required fields, SigV4 signing adds work without an SDK, SDKs in every major language (10 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": 82, "b": 72 } }, { "by": 10, "category": "payments", "leads": "smallest-lightning-tts", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0). Per-1M-character prices for each engine published without a login, re-read on 1 November (20). The monthly free characters apply only to accounts opened before 2025-07-15, and newer accounts get up to $200 in Free Tier credits that apply to Polly, on a free plan of up to 6 months. The Free Tier FAQ says a payment method isn't required for most new customers, but AWS's account docs read on 1 November say AWS might request payment information and holds USD $1 to verify, so half, as on the S3 and Secrets Manager re-checks (10). A person signs up in a browser. IAM can mint keys by API, but only after a human has an account (0). 0 + 20 + 10 + 0 = 30.", "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": 10, "category": "transparency", "leads": "amazon-polly", "name": "Transparency \u0026 trust", "reasons": { "a": "Closed service under the AWS Service Terms, last updated 30 October 2026, with section 50.3 on Polly unchanged (15). The service terms, privacy notice (Last Updated 18 May 2026) and Polly guide agree, a data processing addendum and a public sub-processor list (Last Updated 30 October 2026) exist, but the default permission to use content sits in the service terms rather than the Polly guide (25 of 30). Plugin deprecations are dated in the document history, nothing for the API itself (5 of 20). Sub-processors and regions disclosed, with the region chosen per request. Section 50.3 of the service terms discloses that text kept for service improvement may be stored outside that Region unless the organisation opts out (20).", "b": "Closed service with clear terms naming Smallest Inc. under California law (15). The ZDR page is specific about what each mode keeps, but the terms' no-training clause and the privacy policy's machine-learning use of usage data sit side by side, the privacy policy gives no retention periods, and the policy doesn't mention the DPA a footer link points to (15 of 30). A deprecations page gives statuses, dates and migration steps, and earlier models answer 410 with a pointer. The notice for the default `lightning_v3.1`, dated 2 November, gives 28 days before voices change and v3.1 clones stop working, and the terms let Smallest discontinue services without notice (12 of 20). Two regions named (Mumbai and Oregon) with region-pinned hosts, and only Google Analytics and Fullstory named among third parties, with no sub-processor list found (10 of 20). Total 52." }, "scores": { "a": 80, "b": 70 } } ], "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "Amazon Web Services", "b": "Smallest AI", "name": "Vendor" }, { "a": "https://polly.us-east-1.amazonaws.com/v1", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP, websocket", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Pay per use", "b": "Pay per use", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "none", "b": "0", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-22", "b": "2026-11-02", "name": "Last release" }, { "a": "2026-10-01", "b": "no date given", "name": "Terms last updated" }, { "a": "2026-05-18", "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": "yes", "b": "yes", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "yes", "name": "Arbitration or class-action waiver" }, { "a": "743k npm/wk", "b": "none", "name": "Popularity" }, { "a": "4/5 (8)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Amazon Polly scores 75.4 (BB) on agent readiness against Smallest.ai Lightning TTS's 64.4 (B), and leads in 5 of 7 scored categories. Smallest.ai Lightning TTS leads on payments \u0026 pricing.", "question": "Which is better for AI agents, Amazon Polly or Smallest.ai Lightning TTS?" }, { "answer": "Both need an API key.", "question": "Do Amazon Polly and Smallest.ai Lightning TTS need an API key?" }, { "answer": "Amazon Polly has a hosted endpoint at https://polly.us-east-1.amazonaws.com/v1. No hosted endpoint is listed for Smallest.ai Lightning TTS.", "question": "Can an agent call Amazon Polly and Smallest.ai Lightning TTS without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 80 against 58", "Agent ergonomics, 82 against 72", "Security \u0026 auth, 83 against 52", "Transparency \u0026 trust, 80 against 70" ], "also": [ "Agent-ready, a grade of BB or better", "A hosted endpoint, with nothing to install", "Free to start without a card" ], "goodFor": "Operators already on AWS who want predictable, cheap speech for prompts, notifications and IVR, or generative voices with bidirectional streaming.", "slug": "amazon-polly", "watchFor": "AWS may store and use text to improve the service, possibly outside the Region, unless the organisation sets an AI services opt-out policy" }, { "aheadOn": [ "Payments \u0026 pricing, 40 against 30" ], "also": null, "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": { "amazon-polly": [ { "causes": [ "product" ], "date": "2026-11-01", "delta": 1.8, "from": 73.6, "fromGrade": "BB", "to": 75.4, "toGrade": "BB" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.1, "from": 73.5, "fromGrade": "BB", "to": 73.6, "toGrade": "BB" }, { "causes": [ "pricing", "security", "evidence", "correction" ], "date": "2026-10-17", "delta": -2.1, "from": 75.6, "fromGrade": "BB", "to": 73.5, "toGrade": "BB" } ], "smallest-lightning-tts": null }, "job": { "capability": "speech.tts", "name": "Text-to-speech" }, "others": [ { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-azure-text-to-speech.json", "title": "Amazon Polly vs Azure AI Speech text-to-speech", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-azure-text-to-speech" }, { "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-deepgram-tts.json", "title": "Amazon Polly vs Deepgram Text-to-Speech (Aura-2, Flux TTS)", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-deepgram-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-elevenlabs-tts.json", "title": "Amazon Polly vs ElevenLabs Text to Speech API + MCP", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-elevenlabs-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.json", "title": "Amazon Polly vs Fish Audio TTS API", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-google-cloud-tts.json", "title": "Amazon Polly vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-heygen-voice.json", "title": "Amazon Polly vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-heygen-voice" }, { "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/amazon-polly-vs-minimax-speech.json", "title": "Amazon Polly vs MiniMax Speech (T2A)", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-minimax-speech" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-murf-tts.json", "title": "Amazon Polly vs Murf TTS API + MCP", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-murf-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-playht-tts.json", "title": "Amazon Polly vs PlayHT Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-playht-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-resemble-ai-tts.json", "title": "Amazon Polly vs Resemble AI Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-resemble-ai-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-rime-tts.json", "title": "Amazon Polly vs Rime TTS API + MCP", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-rime-tts" }, { "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.json", "title": "Amazon Polly vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-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-smallest-lightning-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Smallest.ai Lightning TTS", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-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": [ { "amazon-polly": 80, "by": 22, "edge": "amazon-polly", "key": "reliability", "name": "Reliability", "smallest-lightning-tts": 58, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "amazon-polly": 90, "by": 2, "edge": "smallest-lightning-tts", "key": "schema", "name": "Schema \u0026 documentation", "smallest-lightning-tts": 92, "weight": 13 }, { "amazon-polly": 82, "by": 10, "edge": "amazon-polly", "key": "ergonomics", "name": "Agent ergonomics", "smallest-lightning-tts": 72, "weight": 13 }, { "amazon-polly": 83, "by": 31, "edge": "amazon-polly", "key": "security", "name": "Security \u0026 auth", "smallest-lightning-tts": 52, "weight": 14 }, { "amazon-polly": 30, "by": 10, "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 }, { "amazon-polly": 70, "by": 2, "edge": "amazon-polly", "key": "maintenance", "name": "Maintenance \u0026 community", "smallest-lightning-tts": 68, "weight": 7 }, { "amazon-polly": 80, "by": 10, "edge": "amazon-polly", "key": "transparency", "name": "Transparency \u0026 trust", "smallest-lightning-tts": 70, "weight": 7 } ], "summary": "Amazon Polly scores 75.4 (BB) on agent readiness against Smallest.ai Lightning TTS's 64.4 (B), and leads in 5 of 7 scored categories. Smallest.ai Lightning TTS leads on payments \u0026 pricing. Both do text-to-speech.", "tasks": [ { "a": "$0.04 to $0.90", "b": "$0.16 to $0.18", "cheaper": "amazon-polly", "task": "Narrate a 9,000-character script", "what": "about 1,500 words" } ], "tutorials": [], "verdicts": { "amazon-polly": "IAM policies scope access per action and resource, and CloudTrail logs each call. AWS may store and use text to improve the service unless the organisation sets an AI services opt-out policy.", "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/amazon-polly-vs-smallest-lightning-tts", "json": "https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.min.md" }, "markdown": "Amazon Polly scores 75.4 (BB) on agent readiness against Smallest.ai Lightning TTS's 64.4 (B), and leads in 5 of 7 scored categories. Smallest.ai Lightning TTS leads on payments \u0026 pricing. Both do text-to-speech.\n\n- Amazon Polly: grade BB, 75.4/100, rank #61 of 1510. Markdown https://www.anchorterminal.com/tools/amazon-polly.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-polly.json\n- Smallest.ai Lightning TTS: grade B, 64.4/100, rank #471 of 1510. 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### Amazon Polly (BB)\n\nGood for: Operators already on AWS who want predictable, cheap speech for prompts, notifications and IVR, or generative voices with bidirectional streaming.\n\nAhead on:\n- Reliability, 80 against 58\n- Agent ergonomics, 82 against 72\n- Security \u0026 auth, 83 against 52\n- Transparency \u0026 trust, 80 against 70\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n- A hosted endpoint, with nothing to install\n- Free to start without a card\n\nWatch for: AWS may store and use text to improve the service, possibly outside the Region, unless the organisation sets an AI services opt-out policy\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- Payments \u0026 pricing, 40 against 30\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### Security \u0026 auth: Amazon Polly +31\n\n- Amazon Polly (83): Model reading of the checklist, with training and retention in place of least-privilege and injection lines. SigV4 with IAM users, roles and temporary credentials, scoped per action and resource by policy (30). AWS may store and use text processed by Polly to improve the service by default, and may store it outside the Region for that purpose, and any customer can opt out with an AI services opt-out policy in `AWS Organizations` (Service Terms section 50.3, Last Updated 30 October 2026, re-read on 1 November) (10 of 20). Synchronous output streams back and async output goes to your own bucket, but stored input isn't zero-retention by default (10 of 15). CloudTrail logs API calls per caller (15). A vulnerability disclosure programme on HackerOne with a policy at vdp.aws.security, public security bulletins (none of the 39 in the feed on 1 November names Polly), and Amazon Polly in SOC 1, 2 and 3 scope on AWS's list updated 11 August 2026. The security.txt on aws.amazon.com is valid to 2027-10-16 and points to the VDP. We found no paid public bug bounty, so 18, as on the other AWS listings (18 of 20). 30 + 10 + 10 + 15 + 18 = 83.\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### Reliability: Amazon Polly +22\n\n- Amazon Polly (80): AWS Health Dashboard with per-service, per-region history and RSS feeds (20). The Polly us-east-1 feed carried no events on 1 November 2026 (built 00:39 PDT), and the dashboard history file read that day has no event naming Polly other than the Middle East (Bahrain) me-south-1 multi-service event open since 2 March 2026, where Amazon Polly sits at the same disruption status S3 carries in the UAE event. On 15 September 2026, inside the 90-day window, AWS said it can't restore resources and data hosted only in that Region, and no update has followed. The newest event in the file is API Gateway in us-west-2 on 30 October, not Polly. One major event, read as the S3 and Secrets Manager re-checks read the UAE one (10). The 15 September update leaves the window after 14 December. Quotas published per operation and engine, 80 requests a second for standard `SynthesizeSpeech` and 8 for neural, long-form and generative, with burst and concurrency figures, re-read on 1 November (15). Throttled calls return HTTP 400 with `ThrottlingException` and the quotas page says to retry with backoff and jitter, which the SDKs do by default. Synthesis has no side effects, so a retry is safe (15). SLA under the Amazon Machine Learning Language agreement (Last Updated 28 November 2023), which names Amazon Polly, re-read on 1 November (10). GA (10). 20 + 10 + 15 + 15 + 10 + 10 = 80.\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### Agent ergonomics: Amazon Polly +10\n\n- Amazon Polly (82): API reading of the checklist. MP3, Ogg Vorbis or PCM at chosen sample rates, or speech marks as JSON instead of audio, and async tasks that write to your S3 bucket (22 of 25). `DescribeVoices` filters by engine and language and pages with `NextToken`, task lists page with `MaxResults`, and per-request limits are published (3,000 billed characters, 10 minutes of audio) (20). Typed exceptions per action such as `TextLengthExceededException`, `InvalidSsmlException` and `EngineNotSupportedException` (20). Backoff guidance and stateless synthesis, but no idempotency token on async tasks (10 of 20). Three required fields, SigV4 signing adds work without an SDK, SDKs in every major language (10 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### Payments \u0026 pricing: Smallest.ai Lightning TTS +10\n\n- Amazon Polly (30): No x402, MPP or L402 (0). Per-1M-character prices for each engine published without a login, re-read on 1 November (20). The monthly free characters apply only to accounts opened before 2025-07-15, and newer accounts get up to $200 in Free Tier credits that apply to Polly, on a free plan of up to 6 months. The Free Tier FAQ says a payment method isn't required for most new customers, but AWS's account docs read on 1 November say AWS might request payment information and holds USD $1 to verify, so half, as on the S3 and Secrets Manager re-checks (10). A person signs up in a browser. IAM can mint keys by API, but only after a human has an account (0). 0 + 20 + 10 + 0 = 30.\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### Transparency \u0026 trust: Amazon Polly +10\n\n- Amazon Polly (80): Closed service under the AWS Service Terms, last updated 30 October 2026, with section 50.3 on Polly unchanged (15). The service terms, privacy notice (Last Updated 18 May 2026) and Polly guide agree, a data processing addendum and a public sub-processor list (Last Updated 30 October 2026) exist, but the default permission to use content sits in the service terms rather than the Polly guide (25 of 30). Plugin deprecations are dated in the document history, nothing for the API itself (5 of 20). Sub-processors and regions disclosed, with the region chosen per request. Section 50.3 of the service terms discloses that text kept for service improvement may be stored outside that Region unless the organisation opts out (20).\n- Smallest.ai Lightning TTS (70): Closed service with clear terms naming Smallest Inc. under California law (15). The ZDR page is specific about what each mode keeps, but the terms' no-training clause and the privacy policy's machine-learning use of usage data sit side by side, the privacy policy gives no retention periods, and the policy doesn't mention the DPA a footer link points to (15 of 30). A deprecations page gives statuses, dates and migration steps, and earlier models answer 410 with a pointer. The notice for the default `lightning_v3.1`, dated 2 November, gives 28 days before voices change and v3.1 clones stop working, and the terms let Smallest discontinue services without notice (12 of 20). Two regions named (Mumbai and Oregon) with region-pinned hosts, and only Google Analytics and Fullstory named among third parties, with no sub-processor list found (10 of 20). Total 52.\n\n## Score by category\n\n| Category | Weight | Amazon Polly | Smallest.ai Lightning TTS | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 80 | 58 | Amazon Polly +22 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 90 | 92 | Smallest.ai Lightning TTS +2 |\n| Agent ergonomics | 13% (16.2 this run) | 82 | 72 | Amazon Polly +10 |\n| Security \u0026 auth | 14% (17.5 this run) | 83 | 52 | Amazon Polly +31 |\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) | 70 | 68 | Amazon Polly +2 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 80 | 70 | Amazon Polly +10 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **75.4 · BB** | **64.4 · B** | |\n\n## Facts side by side\n\n| Fact | Amazon Polly | Smallest.ai Lightning TTS |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Amazon Web Services | Smallest AI |\n| Hosted endpoint | `https://polly.us-east-1.amazonaws.com/v1` | no (local only) |\n| Transports | HTTP | HTTP, websocket |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| x402 | no | no |\n| Tools exposed | none | 0 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | 2026-10-22 | 2026-11-02 |\n| Terms last updated | 2026-10-01 | no date given |\n| Privacy policy last updated | 2026-05-18 | 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 | yes | yes |\n| Arbitration or class-action waiver | not found in the text | yes |\n| Popularity | 743k npm/wk | none |\n| Agent reviews | 4/5 (8) | none |\n\n## What the same task costs\n\n| Task | Amazon Polly | Smallest.ai Lightning TTS |\n| --- | --- | --- |\n| Narrate a 9,000-character script | $0.04 to $0.90 | $0.16 to $0.18 |\n\n## How the scores have moved\n\n### Amazon Polly\n\n- +1.8 on 1 November 2026: product\n- +0.1 on 27 October 2026: checklist\n- -2.1 on 17 October 2026: pricing, security, new evidence, correction\n\n### Smallest.ai Lightning TTS\n\nNo score change since it was listed.\n\n## Verdicts\n\n**Amazon Polly.** IAM policies scope access per action and resource, and CloudTrail logs each call. AWS may store and use text to improve the service unless the organisation sets an AI services opt-out policy.\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### Amazon Polly\n\n1. Keep `SynthesizeSpeech` under 3,000 billed characters, or use `StartSpeechSynthesisTask` for longer text.\n2. Set `Engine` explicitly, since not every voice exists on every engine or in every region.\n3. Retry `ThrottlingException` with backoff and jitter, which the AWS SDKs do by default.\n4. Check the generative SSML tag list before porting neural SSML.\n5. Ask for `OutputFormat` `json` with speech marks when you need word timings.\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, Amazon Polly or Smallest.ai Lightning TTS?\n\nAmazon Polly scores 75.4 (BB) on agent readiness against Smallest.ai Lightning TTS's 64.4 (B), and leads in 5 of 7 scored categories. Smallest.ai Lightning TTS leads on payments \u0026 pricing.\n\n### Do Amazon Polly and Smallest.ai Lightning TTS need an API key?\n\nBoth need an API key.\n\n### Can an agent call Amazon Polly and Smallest.ai Lightning TTS without installing anything?\n\nAmazon Polly has a hosted endpoint at https://polly.us-east-1.amazonaws.com/v1. 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/amazon-polly-vs-smallest-lightning-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/amazon-polly-vs-smallest-lightning-tts.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"amazon-polly\", \"b\": \"smallest-lightning-tts\"}`. From a terminal: `anchor compare amazon-polly smallest-lightning-tts`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/amazon-polly.json and https://www.anchorterminal.com/api/v1/tools/smallest-lightning-tts.json\n\n## Other comparisons with Amazon Polly or Smallest.ai Lightning TTS\n\n- [Amazon Polly vs Azure AI Speech text-to-speech](https://www.anchorterminal.com/compare/amazon-polly-vs-azure-text-to-speech.md)\n- [Amazon Polly vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts.md)\n- [Amazon Polly vs Deepgram Text-to-Speech (Aura-2, Flux TTS)](https://www.anchorterminal.com/compare/amazon-polly-vs-deepgram-tts.md)\n- [Amazon Polly vs ElevenLabs Text to Speech API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-elevenlabs-tts.md)\n- [Amazon Polly vs Fish Audio TTS API](https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.md)\n- [Amazon Polly vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/amazon-polly-vs-google-cloud-tts.md)\n- [Amazon Polly vs HeyGen Voice](https://www.anchorterminal.com/compare/amazon-polly-vs-heygen-voice.md)\n- [Amazon Polly vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/amazon-polly-vs-inworld-tts.md)\n- [Amazon Polly vs MiniMax Speech (T2A)](https://www.anchorterminal.com/compare/amazon-polly-vs-minimax-speech.md)\n- [Amazon Polly vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-murf-tts.md)\n- [Amazon Polly vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/amazon-polly-vs-playht-tts.md)\n- [Amazon Polly vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/amazon-polly-vs-resemble-ai-tts.md)\n- [Amazon Polly vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-rime-tts.md)\n- [Amazon Polly vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-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 Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/cartesia-tts-vs-smallest-lightning-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": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Amazon Polly vs Smallest.ai Lightning TTS", "url": "" } ], "description": "Amazon Polly scores 75.4 (BB) to Smallest.ai Lightning TTS's 64.4 (B) for text-to-speech. 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