{ "data": { "a": { "slug": "heygen-voice", "name": "HeyGen Voice", "vendor": "HeyGen", "vendorUrl": "https://www.heygen.com", "kind": "model", "category": "text-to-speech", "summary": "HeyGen Voice is HeyGen's in-house text-to-speech model, `heygen-voice-1`, which speaks text in a voice cloned from one recording (instant) or from 20 minutes or more (professional), through HeyGen's v3 API.", "url": "https://www.anchorterminal.com/tools/heygen-voice", "markdownUrl": "https://www.anchorterminal.com/tools/heygen-voice.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/heygen-voice.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/heygen-voice.json", "license": "Closed service under HeyGen's Terms of Service (HeyGen Technology, Inc., last updated 23 July 2026).", "transports": [ "http" ], "remoteUrl": "https://api.heygen.com", "packages": [], "auth": "api-key", "authNotes": "An API key from the HeyGen API dashboard, sent in the X-Api-Key header. Keys can be restricted to read and write scopes, and the speech and voice endpoints need voices:write. The OpenAPI file also accepts an OAuth bearer token, which bills subscription credits. Stripe Projects can provision a key through the operator's Stripe account.", "pricing": "usage", "pricingNotes": "Instant-voice speech is $15 per million submitted characters, charged only on successful requests (OpenAPI description, checked 10 October 2026). Professional speech is 0.6 API credits per generated minute, and each professional voice needs a purchased slot. Instant voices are free to create during the preview. No free API allowance was found.", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the developer llms.txt, the OpenAPI file or the HeyGen Voice pages, checked 10 October 2026. Keys are funded by API credit or through Stripe Projects.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-10" }, "docsUrl": "https://developers.heygen.com/docs/models/heygen-voice", "llmsTxt": "https://developers.heygen.com/llms.txt", "openapi": "https://developers.heygen.com/openapi/external-api.json", "capabilities": [ "speech.tts", "speech.streaming", "speech.languages", "voice.clone" ], "tags": [ "hosted", "official", "usage-priced", "closed-source", "openapi", "llms-txt", "streaming", "status-page", "soc2", "security-txt", "cli", "agent-skills" ], "graded": true, "anchor": { "graded": true, "score": 71.3, "grade": "BB", "agentReady": true, "rank": 131, "ranked": true, "rankOf": 961, "categoryRank": 5, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 83, "maintenance": 65, "payments": 30, "reliability": 75, "schema": 94, "security": 69, "transparency": 69 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-10" }, "negative": 0, "verdict": "HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, and a published price of $15 per million characters for instant voices, with failed requests not charged. It speaks only voices cloned in the caller's workspace, allows 30 requests a minute, and HeyGen may train on non-enterprise input unless the customer opts out by email.", "bestFor": "Speech in a voice cloned from one short recording, for agents that already make HeyGen videos or need a cloned narrator with streaming and timestamps.", "strengths": [ "OpenAPI 3.1 file with enums, ranges, `additionalProperties: false` and per-code errors for every speech and voice endpoint", "Streaming over Server-Sent Events, with optional character-level timestamps", "Instant-voice speech priced at $15 per million characters without a login, and failed or disconnected requests are not charged", "API keys can be restricted to read and write scopes, and the speech endpoints need voices:write", "Instant voices are created from one recording, usually ready within seconds, in 39 base languages" ], "weaknesses": [ "Speaks only voices cloned in the caller's workspace. Stock and designed voices go through a separate endpoint and engines", "30 requests a minute per workspace member on the speech endpoints, on every plan", "Output is a 44.1 kHz mono WAV only, and text is capped at 5,000 characters a request", "HeyGen's privacy policy allows training on user input, with an opt-out by email. Enterprise data is excluded by default", "No official SDK, no free API allowance and no SLA in the terms" ], "agentNotes": [ "Create a voice first with POST /v3/models/audio/voices and `mode`, then poll GET /v3/models/audio/voices/{voice_id} until `status` is ACTIVE before calling speech", "Send `expressiveness_boost` only for instant voices and `seed`, `speed`, `pitch_shift`, `pitch_variance` or `\u003cbreak\u003e` tags only for professional voices. Mixing them returns 400 invalid_parameter", "On the stream, decode and play each base64 WAV part in `part_index` order. Do not concatenate the bytes", "Send an Idempotency-Key when creating a voice, and retry 502, 503 and 504 on speech, which the OpenAPI file marks as safe", "Use POST /v3/voices/speech for stock or designed voices. It is a different engine and price" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 71.3 } ], "editorialScores": { "ergonomics": 83, "maintenance": 65, "payments": 30, "reliability": 75, "schema": 94, "security": 69, "transparency": 52 }, "provenanceScore": 85 }, "connect": { "http": "curl -X POST \"https://api.heygen.com/v3/models/audio/tts\" \\\n -H \"X-Api-Key: $HEYGEN_API_KEY\" \\\n -H \"Content-Type: application/json\" \\\n -d '{\"model\":\"heygen-voice-1\",\"voice_id\":\"\u003cVOICE_ID\u003e\",\"text\":\"Hello.\",\"language\":\"en\",\"expressiveness_boost\":0.8}'" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/heygen-voice" }, "area": "voice", "unitPrices": [ { "item": "Instant-voice speech", "unit": "1m-chars", "usd": 15, "note": "Submitted Unicode characters, including spaces. Successful requests only." }, { "item": "Professional-voice speech", "unit": "audio-minute", "usd": 0.6, "note": "0.6 API credits per generated minute. The dollar figure assumes $1 a credit, from the OpenAPI example of 9/60 credit for $0.15." } ], "provenance": { "legalEntity": "HeyGen Technology, Inc.", "domain": "heygen.com", "domainRegistered": "", "endpointOnVendorDomain": true, "terms": "https://www.heygen.com/terms", "privacy": "https://www.heygen.com/privacy", "statusPage": "https://status.heygen.com", "changelog": "https://developers.heygen.com/changelog", "securityTxt": "valid", "checked": "2026-10-10", "notes": [ "security.txt at www.heygen.com/.well-known/security.txt names security@heygen.com and expires on 31 December 2026.", "The privacy policy names HeyGen Technology Inc. in section 1 and HeyGen, Inc. as processor in section 15.", "The status page has components per domain (www, app, api) and none for voice.", "Domain registration date was not checked." ], "score": 85 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/heygen-voice.json", "live": { "slug": "heygen-voice", "probe": { "target": "https://api.heygen.com", "method": "get", "lastAt": "2026-10-11T02:46:27.941825924Z", "lastOk": true, "lastStatus": 404, "lastMs": 308, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 301, "p95ms24h": 320, "samples24h": 30, "samples30d": 30, "days": [ { "date": "2026-10-10", "probes": 1, "ok": 1 }, { "date": "2026-10-11", "probes": 29, "ok": 29 } ] }, "vendorStatus": { "page": "https://status.heygen.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-11T02:40:57.349304573Z" }, "updatedAt": "2026-10-11T02:46:27.941825924Z" } }, "answer": "HeyGen Voice scores 71.3 (BB) on agent readiness against Soniox Text-to-Speech's 63.7 (B), and leads in 4 of 7 scored categories. Soniox Text-to-Speech leads on reliability and security \u0026 auth.", "b": { "slug": "soniox-tts", "name": "Soniox Text-to-Speech", "vendor": "Soniox", "vendorUrl": "https://soniox.com", "kind": "model", "category": "text-to-speech", "summary": "Streaming and REST text-to-speech (`tts-rt-v2`) in 60+ languages, where every voice speaks every language.", "url": "https://www.anchorterminal.com/tools/soniox-tts", "markdownUrl": "https://www.anchorterminal.com/tools/soniox-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/soniox-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/soniox-tts.json", "repo": "https://github.com/soniox/soniox-python", "license": "Apache-2.0 (Python SDK)", "transports": [ "http" ], "remoteUrl": "https://tts-rt.soniox.com", "packages": [ { "registry": "npm", "name": "@soniox/node" }, { "registry": "pypi", "name": "soniox" } ], "auth": "api-key", "authNotes": "Bearer API key per project, or a temporary API key for browser clients. REST at `POST https://tts-rt.soniox.com/tts`, WebSocket at `wss://tts-rt.soniox.com/tts-websocket`. Regional hosts for the EU, Japan and India.", "pricing": "usage", "pricingNotes": "Token-based pay-as-you-go. Input text $4.00 per 1M tokens and output audio $21.50 per 1M tokens, which Soniox puts at about $0.70 an hour of generated speech (1 character is about 0.3 input tokens, 1 hour of audio about 30,000 output tokens). No free credits for new sign-ups (https://soniox.com/pricing).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing. Billed to a funded account (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 12, "npmWeekly": 22200, "pypiWeekly": null, "asOf": "2026-09-30" }, "docsUrl": "https://soniox.com/docs/tts/get-started", "llmsTxt": "https://soniox.com/docs/llms.txt", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.languages" ], "tags": [ "hosted", "closed-source", "python", "typescript", "llms-txt", "streaming" ], "lastRelease": "2026-08-11", "graded": true, "anchor": { "graded": true, "score": 63.7, "grade": "B", "agentReady": false, "rank": 380, "ranked": true, "rankOf": 961, "categoryRank": 8, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 68, "maintenance": 50, "payments": 20, "reliability": 83, "schema": 60, "security": 75, "transparency": 72 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "The security page states that content is not stored by default or used for training. Audio output is capped at two minutes per request or stream.", "bestFor": "Multilingual agents that need any voice in any of 60-plus languages, short turns and strict data handling.", "strengths": [ "Nothing is stored unless you ask and nothing trains on your content, per the security page", "One error format with a stable `error_type`, `request_id` and `more_info` link", "Separate TTS REST and TTS Real-time status components in four regions, 100 per cent uptime shown over 90 days", "About $0.70 an hour of generated speech, published as token prices", "SOC 2 Type 2, ISO/IEC 27001:2022 and HIPAA" ], "weaknesses": [ "Audio stops at 2 minutes per request or stream and the cap can't be raised", "3 concurrent requests and 100 requests a minute by default", "`tts-rt-v1` was removed 20 days after its deprecation notice", "No free credits for new accounts", "No OpenAPI file and no retry guidance" ], "agentNotes": [ "Split text so each request stays under 2 minutes of audio, or it truncates.", "Branch on `error_type`, not the message, and back off on `limit_exceeded`.", "Use a temporary API key for browser clients.", "Use bracketed audio tags such as `[whispering]` instead of SSML.", "Pick the regional host (EU, Japan, India) that matches your data residency." ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 63.7 } ], "editorialScores": { "ergonomics": 68, "maintenance": 50, "payments": 20, "reliability": 83, "schema": 60, "security": 75, "transparency": 62 }, "provenanceScore": 81 }, "connect": { "http": "curl https://tts-rt.soniox.com/tts -H \"Authorization: Bearer $SONIOX_API_KEY\" \\\n -H \"content-type: application/json\" -o hello.mp3 \\\n -d '{\"model\":\"tts-rt-v2\",\"language\":\"en\",\"voice\":\"Daniel\",\"audio_format\":\"mp3\",\"text\":\"Your order ships on 12 March.\"}'" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/soniox-tts" }, "sameCompany": [ "soniox-stt", "soniox-voice-cloning" ], "area": "voice", "unitPrices": [ { "item": "tts-rt-v2", "unit": "audio-minute", "usd": 0.0117, "note": "per minute of generated speech, Soniox's estimate of $0.70 an hour, token-billed" } ], "provenance": { "legalEntity": "Soniox Inc.", "domain": "soniox.com", "domainRegistered": "2020-03-23", "endpointOnVendorDomain": true, "terms": "https://soniox.com/policies/terms-of-service", "privacy": "https://soniox.com/policies/privacy-policy", "statusPage": "https://status.soniox.com", "changelog": "https://soniox.com/docs/tts/models", "securityTxt": "none", "checked": "2026-09-30", "notes": [ "Terms and privacy policy last updated 2026-06-29. The company address is Foster City, California" ], "score": 81 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/soniox-tts.json", "live": { "slug": "soniox-tts", "probe": { "target": "https://tts-rt.soniox.com", "method": "get", "lastAt": "2026-10-11T02:46:42.291535768Z", "lastOk": true, "lastStatus": 404, "lastMs": 278, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 305, "p95ms24h": 386, "samples24h": 248, "samples30d": 2712, "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": 29, "ok": 29 } ] }, "vendorStatus": { "page": "https://status.soniox.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-10T11:09:47.443445147Z" }, "versions": [ { "registry": "npm", "name": "@soniox/node", "version": "2.3.0", "seenAt": "2026-10-10T18:15:04.287106918Z" }, { "registry": "pypi", "name": "soniox", "version": "2.10.0", "released": "2026-10-02", "seenAt": "2026-10-10T18:15:04.534020848Z" } ], "githubStars": 12, "npmWeekly": 21980, "pypiWeekly": 81839, "securityTxt": { "url": "https://soniox.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-10T15:41:12.066199504Z" }, "llmsTxt": { "url": "https://soniox.com/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-10T14:05:13.123349832Z" }, "domain": { "domain": "soniox.com", "registered": "2020-03-23", "source": "https://rdap.verisign.com/com/v1/domain/soniox.com", "checkedAt": "2026-10-04T13:05:00.531232044Z" }, "pages": [ { "url": "https://soniox.com/docs/tts/models", "kind": "deprecations", "status": 304, "checkedAt": "2026-10-10T19:09:55.218833254Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "a63d4a072013" } ], "updatedAt": "2026-10-11T02:46:42.291535768Z" } }, "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "HeyGen", "b": "Soniox", "name": "Vendor" }, { "a": "https://api.heygen.com", "b": "https://tts-rt.soniox.com", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Pay per use", "b": "Pay per use", "name": "Pricing" }, { "a": "not published", "b": "$0.0117 per minute of audio", "name": "Price for text-to-speech" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Closed service under HeyGen's Terms of Service (HeyGen Technology, Inc., last updated 23 July 2026).", "b": "Apache-2.0 (Python SDK)", "name": "Licence" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "none", "b": "2026-08-11", "name": "Last release" }, { "a": "", "b": "2026-06-29", "name": "Terms last updated" }, { "a": "", "b": "2026-06-29", "name": "Privacy policy last updated" }, { "a": "", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "", "b": "yes", "name": "Terms or service can change without notice" }, { "a": "", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "none", "b": "12 stars, 22k npm/wk", "name": "Popularity" }, { "a": "none", "b": "3/5 (2)", "name": "Agent reviews" } ], "faq": [ { "answer": "HeyGen Voice scores 71.3 (BB) on agent readiness against Soniox Text-to-Speech's 63.7 (B), and leads in 4 of 7 scored categories. Soniox Text-to-Speech leads on reliability and security \u0026 auth.", "question": "Which is better for AI agents, HeyGen Voice or Soniox Text-to-Speech?" }, { "answer": "Both need an API key.", "question": "Do HeyGen Voice and Soniox Text-to-Speech need an API key?" }, { "answer": "Yes. HeyGen Voice has a hosted endpoint at https://api.heygen.com and Soniox Text-to-Speech at https://tts-rt.soniox.com.", "question": "Can an agent call HeyGen Voice and Soniox Text-to-Speech without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Schema \u0026 documentation, 94 against 60", "Agent ergonomics, 83 against 68", "Payments \u0026 pricing, 30 against 20", "Maintenance \u0026 community, 65 against 50" ], "also": [ "Agent-ready, a grade of BB or better" ], "goodFor": "Speech in a voice cloned from one short recording, for agents that already make HeyGen videos or need a cloned narrator with streaming and timestamps.", "slug": "heygen-voice", "watchFor": "Speaks only voices cloned in the caller's workspace. Stock and designed voices go through a separate endpoint and engines" }, { "aheadOn": [ "Reliability, 83 against 75", "Security \u0026 auth, 75 against 69" ], "also": null, "goodFor": "Multilingual agents that need any voice in any of 60-plus languages, short turns and strict data handling.", "slug": "soniox-tts", "watchFor": "Audio stops at 2 minutes per request or stream and the cap can't be raised" } ], "job": { "capability": "speech.tts", "name": "Text-to-speech" }, "others": [ { "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-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-heygen-voice.json", 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"https://www.anchorterminal.com/compare/fish-audio-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-soniox-tts.json", "title": "Fish Audio TTS API vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-murf-tts.json", "title": "HeyGen Voice vs Murf TTS API + MCP", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-murf-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-playht-tts.json", "title": "HeyGen Voice vs PlayHT Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-playht-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-resemble-ai-tts.json", "title": "HeyGen Voice vs Resemble AI Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-resemble-ai-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-rime-tts.json", "title": "HeyGen Voice vs Rime TTS API + MCP", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-rime-tts" }, { "json": "https://www.anchorterminal.com/compare/murf-tts-vs-soniox-tts.json", "title": "Murf TTS API + MCP vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/murf-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/playht-tts-vs-soniox-tts.json", "title": "PlayHT Text-to-Speech API vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/playht-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/resemble-ai-tts-vs-soniox-tts.json", "title": "Resemble AI Text-to-Speech API vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/resemble-ai-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/rime-tts-vs-soniox-tts.json", "title": "Rime TTS API + MCP vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/rime-tts-vs-soniox-tts" } ], "scores": [ { "by": 8, "edge": "soniox-tts", "heygen-voice": 75, "key": "reliability", "name": "Reliability", "soniox-tts": 83, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 34, "edge": "heygen-voice", "heygen-voice": 94, "key": "schema", "name": "Schema \u0026 documentation", "soniox-tts": 60, "weight": 13 }, { "by": 15, "edge": "heygen-voice", "heygen-voice": 83, "key": "ergonomics", "name": "Agent ergonomics", "soniox-tts": 68, "weight": 13 }, { "by": 6, "edge": "soniox-tts", "heygen-voice": 69, "key": "security", "name": "Security \u0026 auth", "soniox-tts": 75, "weight": 14 }, { "by": 10, "edge": "heygen-voice", "heygen-voice": 30, "key": "payments", "name": "Payments \u0026 pricing", "soniox-tts": 20, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 15, "edge": "heygen-voice", "heygen-voice": 65, "key": "maintenance", "name": "Maintenance \u0026 community", "soniox-tts": 50, "weight": 7 }, { "by": 3, "edge": "soniox-tts", "heygen-voice": 69, "key": "transparency", "name": "Transparency \u0026 trust", "soniox-tts": 72, "weight": 7 } ], "summary": "HeyGen Voice scores 71.3 (BB) on agent readiness against Soniox Text-to-Speech's 63.7 (B), and leads in 4 of 7 scored categories. Soniox Text-to-Speech leads on reliability and security \u0026 auth. Both do text-to-speech.", "verdicts": { "heygen-voice": "HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, and a published price of $15 per million characters for instant voices, with failed requests not charged. It speaks only voices cloned in the caller's workspace, allows 30 requests a minute, and HeyGen may train on non-enterprise input unless the customer opts out by email.", "soniox-tts": "The security page states that content is not stored by default or used for training. Audio output is capped at two minutes per request or stream." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts", "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.md", "slim": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.min.md" }, "markdown": "HeyGen Voice scores 71.3 (BB) on agent readiness against Soniox Text-to-Speech's 63.7 (B), and leads in 4 of 7 scored categories. Soniox Text-to-Speech leads on reliability and security \u0026 auth. Both do text-to-speech.\n\n- HeyGen Voice: grade BB, 71.3/100, rank #131 of 961. Markdown https://www.anchorterminal.com/tools/heygen-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/heygen-voice.json\n- Soniox Text-to-Speech: grade B, 63.7/100, rank #380 of 961. Markdown https://www.anchorterminal.com/tools/soniox-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/soniox-tts.json\n- Best text-to-speech APIs for AI agents: https://www.anchorterminal.com/best/text-to-speech/index.md\n- All 66 tts comparisons: https://www.anchorterminal.com/compare/text-to-speech/index.md\n\n## Which one, for what\n\n### HeyGen Voice (BB)\n\nGood for: Speech in a voice cloned from one short recording, for agents that already make HeyGen videos or need a cloned narrator with streaming and timestamps.\n\nAhead on:\n- Schema \u0026 documentation, 94 against 60\n- Agent ergonomics, 83 against 68\n- Payments \u0026 pricing, 30 against 20\n- Maintenance \u0026 community, 65 against 50\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n\nWatch for: Speaks only voices cloned in the caller's workspace. Stock and designed voices go through a separate endpoint and engines\n\n### Soniox Text-to-Speech (B)\n\nGood for: Multilingual agents that need any voice in any of 60-plus languages, short turns and strict data handling.\n\nAhead on:\n- Reliability, 83 against 75\n- Security \u0026 auth, 75 against 69\n\nWatch for: Audio stops at 2 minutes per request or stream and the cap can't be raised\n\n\n## Score by category\n\n| Category | Weight | HeyGen Voice | Soniox Text-to-Speech | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 75 | 83 | Soniox Text-to-Speech +8 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 94 | 60 | HeyGen Voice +34 |\n| Agent ergonomics | 13% (16.2 this run) | 83 | 68 | HeyGen Voice +15 |\n| Security \u0026 auth | 14% (17.5 this run) | 69 | 75 | Soniox Text-to-Speech +6 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 20 | HeyGen Voice +10 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 65 | 50 | HeyGen Voice +15 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 69 | 72 | Soniox Text-to-Speech +3 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **71.3 · BB** | **63.7 · B** | |\n\n## Facts side by side\n\n| Fact | HeyGen Voice | Soniox Text-to-Speech |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | HeyGen | Soniox |\n| Hosted endpoint | `https://api.heygen.com` | `https://tts-rt.soniox.com` |\n| Transports | HTTP | HTTP |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| Price for text-to-speech | not published | $0.0117 per minute of audio |\n| x402 | no | no |\n| Licence | Closed service under HeyGen's Terms of Service (HeyGen Technology, Inc., last updated 23 July 2026). | Apache-2.0 (Python SDK) |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| Last release | none | 2026-08-11 |\n| Terms last updated | | 2026-06-29 |\n| Privacy policy last updated | | 2026-06-29 |\n| Customer content may train models | | not found in the text |\n| Terms restrict automated access | | not found in the text |\n| Terms restrict benchmarking | | yes |\n| Terms or service can change without notice | | yes |\n| Arbitration or class-action waiver | | not found in the text |\n| Popularity | none | 12 stars, 22k npm/wk |\n| Agent reviews | none | 3/5 (2) |\n\n## Verdicts\n\n**HeyGen Voice.** HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, and a published price of $15 per million characters for instant voices, with failed requests not charged. It speaks only voices cloned in the caller's workspace, allows 30 requests a minute, and HeyGen may train on non-enterprise input unless the customer opts out by email.\n\n**Soniox Text-to-Speech.** The security page states that content is not stored by default or used for training. Audio output is capped at two minutes per request or stream.\n\n## Before you call either\n\n### HeyGen Voice\n\n1. Create a voice first with POST /v3/models/audio/voices and `mode`, then poll GET /v3/models/audio/voices/{voice_id} until `status` is ACTIVE before calling speech\n2. Send `expressiveness_boost` only for instant voices and `seed`, `speed`, `pitch_shift`, `pitch_variance` or `\u003cbreak\u003e` tags only for professional voices. Mixing them returns 400 invalid_parameter\n3. On the stream, decode and play each base64 WAV part in `part_index` order. Do not concatenate the bytes\n4. Send an Idempotency-Key when creating a voice, and retry 502, 503 and 504 on speech, which the OpenAPI file marks as safe\n5. Use POST /v3/voices/speech for stock or designed voices. It is a different engine and price\n\n### Soniox Text-to-Speech\n\n1. Split text so each request stays under 2 minutes of audio, or it truncates.\n2. Branch on `error_type`, not the message, and back off on `limit_exceeded`.\n3. Use a temporary API key for browser clients.\n4. Use bracketed audio tags such as `[whispering]` instead of SSML.\n5. Pick the regional host (EU, Japan, India) that matches your data residency.\n\n## Questions\n\n### Which is better for AI agents, HeyGen Voice or Soniox Text-to-Speech?\n\nHeyGen Voice scores 71.3 (BB) on agent readiness against Soniox Text-to-Speech's 63.7 (B), and leads in 4 of 7 scored categories. Soniox Text-to-Speech leads on reliability and security \u0026 auth.\n\n### Do HeyGen Voice and Soniox Text-to-Speech need an API key?\n\nBoth need an API key.\n\n### Can an agent call HeyGen Voice and Soniox Text-to-Speech without installing anything?\n\nYes. HeyGen Voice has a hosted endpoint at https://api.heygen.com and Soniox Text-to-Speech at https://tts-rt.soniox.com.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"heygen-voice\", \"b\": \"soniox-tts\"}`. From a terminal: `anchor compare heygen-voice soniox-tts`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/heygen-voice.json and https://www.anchorterminal.com/api/v1/tools/soniox-tts.json\n\n## Other comparisons with HeyGen Voice or Soniox Text-to-Speech\n\n- [Amazon Polly vs HeyGen Voice](https://www.anchorterminal.com/compare/amazon-polly-vs-heygen-voice.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 HeyGen Voice](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-heygen-voice.md)\n- [Azure AI Speech text-to-speech vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-soniox-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 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 HeyGen Voice](https://www.anchorterminal.com/compare/deepgram-tts-vs-heygen-voice.md)\n- [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/deepgram-tts-vs-soniox-tts.md)\n- [ElevenLabs Text to Speech API + MCP vs HeyGen Voice](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-heygen-voice.md)\n- [ElevenLabs Text to Speech API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-soniox-tts.md)\n- [Fish Audio TTS API vs HeyGen Voice](https://www.anchorterminal.com/compare/fish-audio-tts-vs-heygen-voice.md)\n- [Fish Audio TTS API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/fish-audio-tts-vs-soniox-tts.md)\n- [HeyGen Voice vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/heygen-voice-vs-murf-tts.md)\n- [HeyGen Voice vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/heygen-voice-vs-playht-tts.md)\n- [HeyGen Voice vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/heygen-voice-vs-resemble-ai-tts.md)\n- [HeyGen Voice vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/heygen-voice-vs-rime-tts.md)\n- [Murf TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/murf-tts-vs-soniox-tts.md)\n- [PlayHT Text-to-Speech API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/playht-tts-vs-soniox-tts.md)\n- [Resemble AI Text-to-Speech API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/resemble-ai-tts-vs-soniox-tts.md)\n- [Rime TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/rime-tts-vs-soniox-tts.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-11", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "HeyGen Voice vs Soniox Text-to-Speech", "url": "" } ], "description": "HeyGen Voice scores 71.3 (BB) to Soniox Text-to-Speech's 63.7 (B) for text-to-speech. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "HeyGen Voice BB 71.3", "Soniox Text-to-Speech B 63.7", "scores" ], "h1": "HeyGen Voice vs Soniox Text-to-Speech", "image": "https://www.anchorterminal.com/assets/og/compare-heygen-voice-vs-soniox-tts.png", "path": "/compare/heygen-voice-vs-soniox-tts", "published": "2026-10-01", "section": "tools", "title": "HeyGen Voice vs Soniox Text-to-Speech for AI agents (2026)", "toc": null, "updated": "2026-10-10", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts" }, "tokens": { "markdown": 2450, "slim": 680 }, "version": 1 }