{ "data": { "a": { "slug": "google-cloud-tts", "name": "Google Cloud Text-to-Speech", "vendor": "Google Cloud", "vendorUrl": "https://cloud.google.com/text-to-speech", "kind": "model", "category": "text-to-speech", "summary": "Google Cloud's Text-to-Speech API synthesises speech from text or SSML over REST and gRPC, with streaming, long-audio jobs, Chirp 3 HD voices, Gemini-TTS models steered by natural-language prompts, and older WaveNet, Neural2 and Standard voices.", "url": "https://www.anchorterminal.com/tools/google-cloud-tts", "markdownUrl": "https://www.anchorterminal.com/tools/google-cloud-tts.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/google-cloud-tts.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/google-cloud-tts.json", "dns": "google-cloud-tts.grade.anchorterminal.com", "repo": "https://github.com/googleapis/google-cloud-python/tree/main/packages/google-cloud-texttospeech", "transports": [ "http" ], "packages": [ { "registry": "pypi", "name": "google-cloud-texttospeech" }, { "registry": "npm", "name": "@google-cloud/text-to-speech" } ], "auth": "oauth", "authNotes": "OAuth 2.0 bearer token from a service account or `gcloud` (Application Default Credentials) on a project with billing and the API turned on, scoped through IAM. The discovery document also accepts `access_token` and `key` as URL query parameters.", "pricing": "usage", "pricingNotes": "Chirp 3 HD $30 per million characters after 1 million free a month, Neural2 $16, Studio $160 and Standard and WaveNet $4 after 4 million free. Gemini-TTS is billed per token, from $0.50 per million text tokens and $10 per million audio tokens on Gemini 2.5 Flash TTS. Billing must be enabled.", "priceSummary": "Pay per use", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the docs or pricing page (checked 2026-11-06). Billing runs through a Cloud Billing account.", "endpoints": [] }, "toolCount": 0, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-11-06" }, "docsUrl": "https://docs.cloud.google.com/text-to-speech/docs", "openapi": "https://texttospeech.googleapis.com/$discovery/rest?version=v1", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.ssml", "speech.languages" ], "tags": [ "hosted", "freemium", "closed-source", "python", "typescript", "enterprise", "streaming", "batch", "async-jobs", "card-required" ], "lastRelease": "2025-12-30", "graded": true, "anchor": { "graded": true, "score": 66.9, "grade": "B", "agentReady": false, "rank": 351, "ranked": true, "rankOf": 1510, "categoryRank": 8, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 65, "maintenance": 25, "payments": 20, "reliability": 85, "schema": 80, "security": 80, "transparency": 87 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "Cloud TTS has a typed discovery document, a 99.9 per cent SLA, no logging of text or audio, and voices from $4 to $160 per million characters. Its release notes stop at 30 December 2025, the newest Gemini TTS models ship only on the Agent Platform API, and tokens can travel in the URL.", "bestFor": "Teams already on Google Cloud wanting many languages, SSML and an SLA.", "strengths": [ "Google says it doesn't log any customer Cloud TTS text or audio, and the service is stateless", "99.9 per cent monthly uptime SLA with financial credits", "Text-to-Speech appears in none of the Google Cloud incidents since 8 August 2026", "Discovery document and gRPC protos type every method", "Monthly free allowances of 1 million Chirp 3 HD and 4 million Standard or WaveNet characters" ], "weaknesses": [ "No release note since 30 December 2025, though a Gemini 3.1 TTS preview model is listed", "Gemini 3.8 Flash TTS is GA only on the Agent Platform API, not the Cloud TTS API", "The discovery document accepts tokens and keys as URL query parameters", "Billing with a card is needed even for the free allowance", "No llms.txt, and no guidance on quota errors or backoff" ], "agentNotes": [ "Send OAuth tokens in the Authorization header, never as `access_token` or `key` in the URL", "Use `synthesizeLongAudio` with a Cloud Storage bucket for long text, and `text:synthesize` for short replies", "Pick Chirp 3 HD for natural voices with SSML, and Gemini-TTS when the delivery needs prompt steering", "Check whether the Gemini TTS model you want is on the Cloud TTS API or only on the Agent Platform API", "Stay within 200 requests a minute on Chirp 3 voices, which have their own quota" ], "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": 66.9 } ], "editorialScores": { "ergonomics": 65, "maintenance": 25, "payments": 20, "reliability": 85, "schema": 80, "security": 80, "transparency": 75 }, "provenanceScore": 98, "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 google-cloud-texttospeech" }, "letme": { "capability": "https://letme.dev/speech.tts", "tool": "https://letme.dev/google-cloud-tts" }, "sameCompany": [ "gemini-api", "vertex-ai", "gemini-embedding", "vertex-ai-tuning", "cloud-run-gpus", "google-model-armor", "google-imagen", "google-veo", "google-lyria", "google-speech-to-text", "gemini-live", "google-adk", "google-memory-bank", "google-secret-manager", "google-cloud-document-ai", "google-weather-api", "chrome-devtools-mcp", "google-maps-platform", "google-cloud-translation", "google-calendar-api", "firebase-cloud-messaging", "google-cloud-storage", "google-drive-api", "gemini-enterprise", "gemini-cli", "google-search-console", "google-ads-api", "google-forms", "google-sheets-api", "gmail-api", "google-people-api" ], "area": "voice", "unitPrices": [ { "item": "Chirp 3 HD voices", "unit": "1m-chars", "usd": 30, "note": "after 1 million free characters a month" }, { "item": "Neural2 voices", "unit": "1m-chars", "usd": 16, "note": "after 1 million free characters a month" }, { "item": "Standard and WaveNet voices", "unit": "1m-chars", "usd": 4, "note": "after 4 million free characters a month" }, { "item": "Studio voices", "unit": "1m-chars", "usd": 160 }, { "item": "Gemini 2.5 Flash TTS audio output", "unit": "1m-tokens", "usd": 10, "note": "25 audio tokens a second; text input $0.50 per million tokens" } ], "provenance": { "legalEntity": "Google LLC", "domain": "google.com", "domainRegistered": "1997-09-15", "domainNote": "The endpoint is on googleapis.com, Google's API domain. google.com was registered in 1997.", "endpointOnVendorDomain": true, "terms": "https://cloud.google.com/terms", "privacy": "https://policies.google.com/privacy", "statusPage": "https://status.cloud.google.com", "changelog": "https://docs.cloud.google.com/text-to-speech/docs/release-notes", "securityTxt": "valid", "checked": "2026-11-06", "notes": [ "Cloud TTS is offered under the Google Cloud terms, with Google LLC as the contracting party, as on google-speech-to-text.", "docs.cloud.google.com and cloud.google.com robots.txt allow the documentation, pricing and SLA pages read. status.cloud.google.com/robots.txt allows all paths.", "No llms.txt was found at docs.cloud.google.com/llms.txt or under /text-to-speech/." ], "score": 98 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/google-cloud-tts.json", "live": { "slug": "google-cloud-tts", "versions": [ { "registry": "github", "name": "googleapis/google-cloud-python", "version": "google-maps-solar-v0.6.3", "released": "2026-11-05", "seenAt": "2026-11-06T23:29:18.173118344Z" }, { "registry": "npm", "name": "@google-cloud/text-to-speech", "version": "7.2.0", "seenAt": "2026-11-06T23:29:16.557801912Z" }, { "registry": "pypi", "name": "google-cloud-texttospeech", "version": "2.38.0", "released": "2026-10-01", "seenAt": "2026-11-06T23:29:16.41496035Z" } ], "githubStars": 5415, "npmWeekly": 443672, "pypiWeekly": 2259800, "securityTxt": { "url": "https://google.com/.well-known/security.txt", "state": "valid", "expires": "2030-04-01T00:00:00z", "checkedAt": "2026-11-07T16:01:22.068349931Z" }, "pages": [ { "url": "https://docs.cloud.google.com/text-to-speech/docs/release-notes", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:05:56.03164941Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "cc773af4f925" } ], "updatedAt": "2026-11-07T16:01:22.068349931Z" } }, "answer": "HeyGen Voice scores 73.6 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 4 of 7 scored categories. Google Cloud Text-to-Speech leads on reliability, security \u0026 auth and transparency \u0026 trust.", "b": { "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` with a Turbo variant, which speaks HeyGen's public voices or voices cloned from one recording (instant) or 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", "dns": "heygen-voice.grade.anchorterminal.com", "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": "API speech is $30 per million characters on heygen-voice-1 and $15 on heygen-voice-1-turbo, per the HeyGen Voice page (checked 1 November 2026). `heygen-voice-1-turbo-free` is free until 30 November 2026 for public and instant voices, with no credit balance needed and shared capacity. Speech to speech is $0.12 per output minute. Each professional voice needs a purchased slot, from $29 a month. Instant voices are free to create during the preview.", "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 1 November 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.voices", "speech.languages", "voice.clone" ], "tags": [ "hosted", "official", "usage-priced", "closed-source", "openapi", "llms-txt", "streaming", "status-page", "soc2", "security-txt", "cli", "agent-skills" ], "lastRelease": "2026-10-20", "graded": true, "anchor": { "graded": true, "score": 73.6, "grade": "BB", "agentReady": true, "rank": 103, "ranked": true, "rankOf": 1510, "categoryRank": 4, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 88, "maintenance": 65, "payments": 40, "reliability": 75, "schema": 97, "security": 69, "transparency": 66 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-01" }, "negative": 0, "verdict": "HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, a choice of audio formats and published prices of $30 per million characters, $15 on Turbo. Turbo Free costs nothing until 30 November 2026. Requests are limited to 30 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 or raw bytes, with optional character-level timestamps and PCM16, MP3, mu-law or A-law output", "Turbo Free speaks public and instant voices at no charge and with no credit balance until 30 November 2026", "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": [ "30 requests a minute per workspace member on the speech endpoints by default, and Turbo Free's shared capacity can return 429 below that", "Turbo Free ends on 30 November 2026 and carries no latency or availability guarantee", "Text is capped at 5,000 characters a request, and professional voices need a purchased slot each", "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 SLA in the terms, and instant voice creation is still a preview" ], "agentNotes": [ "Start tests with `model: heygen-voice-1-turbo-free` and a public voice from GET /v3/models/audio/voices?type=public. It never falls back to a paid model", "Create a clone 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. Professional voices reject it, and instant voices ignore `seed`, `speed`, `pitch_shift` and `pitch_variance`", "On a 429 without Retry-After, back off exponentially. Capacity 429s carry no header", "Use POST /v3/voices/speech for catalogue or designed voices. It is a different endpoint and price" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 4, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 73.6 } ], "editorialScores": { "ergonomics": 88, "maintenance": 65, "payments": 40, "reliability": 75, "schema": 97, "security": 69, "transparency": 52 }, "provenanceScore": 79, "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": { "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": "Speech, heygen-voice-1", "unit": "1m-chars", "usd": 30, "note": "Public, instant and professional voices, per the HeyGen Voice page." }, { "item": "Speech, heygen-voice-1-turbo", "unit": "1m-chars", "usd": 15, "note": "Public and instant voices only, lower latency." }, { "item": "Speech, heygen-voice-1-turbo-free", "unit": "1m-chars", "usd": 0, "note": "Free until 30 November 2026. Public and instant voices, shared capacity, no availability guarantee." }, { "item": "Speech to speech", "unit": "audio-minute", "usd": 0.12, "note": "Per minute of output audio, billed per second. Instant voices only." } ], "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": "2026-11-01", "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": 79 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/heygen-voice.json", "live": { "slug": "heygen-voice", "probe": { "target": "https://api.heygen.com", "method": "get", "lastAt": "2026-11-07T19:22:11.547994058Z", "lastOk": true, "lastStatus": 404, "lastMs": 355, "authRequired": false, "uptime24h": 100, "uptime30d": 99.99, "p50ms24h": 312, "p95ms24h": 415, "samples24h": 238, "samples30d": 6884, "days": [ { "date": "2026-10-10", "probes": 1, "ok": 1 }, { "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": 248, "ok": 248 }, { "date": "2026-10-30", "probes": 249, "ok": 249 }, { "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": 240 }, { "date": "2026-11-07", "probes": 197, "ok": 197 } ] }, "vendorStatus": { "page": "https://status.heygen.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-11-07T19:22:15.267706389Z" }, "securityTxt": { "url": "https://heygen.com/.well-known/security.txt", "state": "valid", "expires": "2026-12-31T08:00:00Z", "checkedAt": "2026-11-07T16:00:15.774625059Z" }, "llmsTxt": { "url": "https://developers.heygen.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:42.083130335Z" }, "domain": { "domain": "heygen.com", "registered": "2015-10-19", "source": "https://rdap.verisign.com/com/v1/domain/heygen.com", "checkedAt": "2026-11-01T14:11:45.602901172Z" }, "pages": [ { "url": "https://developers.heygen.com/changelog", "kind": "deprecations", "status": 200, "checkedAt": "2026-11-07T14:04:02.83561623Z", "changedAt": "2026-11-07T14:04:02.83561623Z", "fingerprint": "1b58e3df0897" }, { "url": "https://www.heygen.com/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:29:45.494246628Z", "changedAt": "2026-11-04T08:40:59.471841774Z", "fingerprint": "376d487f17dd" }, { "url": "https://www.heygen.com/terms", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:29:47.885215955Z", "changedAt": "2026-11-04T08:41:02.102076318Z", "fingerprint": "299d87563af3" } ], "updatedAt": "2026-11-07T19:22:11.547994058Z" } }, "edges": [ { "by": 40, "category": "maintenance", "leads": "heygen-voice", "name": "Maintenance \u0026 community", "reasons": { "a": "Read as a model. The newest release note is still 30 December 2025 (Chirp 3 HD in yue-HK), 311 days ago, and `gemini-3.1-flash-tts-preview` appears on the Gemini-TTS page with no dated note (0). In the 90 days from 8 August the Python client shipped 2.38.0 on 1 October, whose only change declares Python 3.15 support, which counts half and can't set the recency line (0). Release notes, a public issue tracker and paid support (10 of 15). Official client libraries, Python at 2.38.0 and Node at 7.2.0 (10 of 15). Package CI not checked (5 of 10). Total 25.", "b": "Read as a model. The changelog's newest voice entry, speech to speech, is in the RSS feed on 20 October 2026 (30). Seven voice entries between 9 and 20 October alone, instant voices, Turbo, public voices with timestamps, previews, voices from an image, professional voices without a language and speech to speech, and dated sunsets elsewhere in the API, v1 and v2 on 31 October 2026, announced in April (20). Public changelog with RSS and a developer Discord. Answers were not sampled (10 of 15). No official SDK. HeyGen ships a CLI and agent skills (5 of 15). No package health record was read (0). Total 65." }, "scores": { "a": 25, "b": 65 } }, { "by": 23, "category": "ergonomics", "leads": "heygen-voice", "name": "Agent ergonomics", "reasons": { "a": "API reading of the checklist. Audio returns Base64 in JSON or streams over gRPC, with encoding, sample rate and timepoints selectable (15 of 25). `voices.list` filters by language code with no paging, and operations list with page tokens (15 of 20). Standard gRPC status codes with messages, generic rather than TTS-specific (15 of 20). Synthesis is stateless and long audio runs as an operation, with no idempotency key (10 of 20). A first call needs a project, billing, OAuth credentials and a voice, and Cloud Storage for long audio. Official client libraries in many languages, of which Python and Node were checked (10 of 15). Total 65.", "b": "API reading of the checklist. The completed response is a URL and a duration, streaming returns WAV parts as they are made, and timestamps come only when asked. Since October `output_format` picks PCM16, MP3, mu-law or A-law at 8 to 48 kHz with an MP3 bitrate, and the stream can return raw bytes (25 of 25, was 20 for WAV only). Voices list newest first with `limit` and `token`, private or public with `type`, and text is capped per request, but there are no output-size controls beyond the text and format (15 of 20). Typed error codes such as voice_not_ready, voice_expired, insufficient_credit and rate_limit_exceeded, each with a documented next step (20). Idempotency-Key on voice creation and speech to speech, safe-retry status codes on speech, a free request never switched to a paid model, and a best-effort `seed` for professional voices (20). Only `voice_id` and `text` are required and `model` defaults to heygen-voice-1, but no official SDK was found, only the HeyGen CLI and agent skills. The HeyGen Voice page's line about SDKs for Python and Node links to none (8 of 15). Total 88." }, "scores": { "a": 65, "b": 88 } }, { "by": 21, "category": "transparency", "leads": "google-cloud-tts", "name": "Transparency \u0026 trust", "reasons": { "a": "Closed service under the Google Cloud terms, with Apache-2.0 clients (15). The data logging page, the terms and the privacy notice agree that TTS text and audio aren't logged, and a DPA and sub-processor list exist, as read for google-speech-to-text (25 of 30). Release notes mark preview and GA, and the Cloud terms carry notice before a GA capability is discontinued, but Gemini-TTS is moving to the Agent Platform API with no dated notice for the Cloud TTS models (15 of 20). Regional endpoints (global, us, eu and others) and a public sub-processor list (20). Total 75.", "b": "Closed service with terms dated 23 July 2026, per the 10 October check. Paid plans own their output, and free-plan output is limited to non-commercial use (15). Privacy policy, terms and security page agree that non-enterprise input can train models with an opt-out by email, and differ on the entity name (HeyGen Technology Inc. and HeyGen, Inc.). No retention period for voice or speech data (12 of 30). Dated deprecation notices in the changelog, such as the v1 and v2 sunset on 31 October 2026, and an end date for Turbo Free with a promise of notice before it changes, but no notice yet for this model (15 of 20). Subprocessors are listed on the security portal, which was not read, and the privacy policy says data may be processed in the United States (10 of 20). Total 52." }, "scores": { "a": 87, "b": 66 } }, { "by": 20, "category": "payments", "leads": "heygen-voice", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0). Per-character and per-token prices for every voice family published without a login (20). Monthly free characters (1 million for Chirp 3 HD, 4 million for Standard and WaveNet) need billing enabled, which needs a card (0). A person creates a project and billing account in a browser (0). Total 20.", "b": "No x402, MPP or L402 in the llms.txt, the OpenAPI file or the voice pages (0). The HeyGen Voice page publishes API speech at $30 per million characters on heygen-voice-1, $15 on Turbo and speech to speech at $0.12 a minute, without a login (20). `heygen-voice-1-turbo-free` is free until 30 November 2026 with a free API key and no credit balance, for public and instant voices, under shared capacity. Neither the docs nor the HeyGen Voice page say whether the free key needs a card at sign-up, and \"no credit balance\" isn't the same statement. HeyGen's pricing FAQ says the web Free plan needs no card, but doesn't say that covers API keys, and the API dashboard's host couldn't be read. So half, the reading listings with unstated card terms get (anthropic-api, zep, and fish-audio-voice-cloning for its free model to the same date), until it ends (10). Stripe Projects lists heygen/api, which lets an agent create the account and receive a key through the operator's Stripe login and saved payment method. A person still has to log in to Stripe once (10). 0+20+10+10 = 40." }, "scores": { "a": 20, "b": 40 } }, { "by": 17, "category": "schema", "leads": "heygen-voice", "name": "Schema \u0026 documentation", "reasons": { "a": "Discovery document revision 20260827 with typed methods and 26 schemas, and protocol buffers for gRPC (25). No llms.txt found (0). The Chirp 3 HD and Gemini-TTS pages say which voices suit which use and list formats and limits, but the reference doesn't say when to choose streaming or long audio (15 of 20). Typed messages with enums for encoding and gender and required fields (15). Samples in several languages, standard status codes with little method-specific error detail (10 of 15). Versioned v1 and v1beta1 with dated release notes (15). Total 80.", "b": "OpenAPI 3.1 file at developers.heygen.com/openapi/external-api.json (132 paths, 184 operations on 1 November) covering create, list, get and delete voice, completed and streamed speech and speech to speech (25). llms.txt with a Markdown twin of every page (10). Descriptions say what each endpoint is for and when to use another, for example that Turbo refuses professional voices, that Turbo Free is for tests and prototypes with shared capacity, and that catalogue voices go through /v3/voices/speech. Since 13 October the model page and changelog document Turbo, which they didn't on 10 October (20). Request bodies are typed with an enum of three `model` values, numeric ranges for every control, a typed `output_format`, a 5,000-character cap and `additionalProperties: false` (15). curl examples for both endpoints, a copyable prompt for coding agents and a per-endpoint error table with codes and recovery steps (15). Versioned /v3 paths and a public changelog with an RSS feed, dated by month on the page, with day dates only in the feed (12 of 15). Total 97." }, "scores": { "a": 80, "b": 97 } }, { "by": 11, "category": "security", "leads": "google-cloud-tts", "name": "Security \u0026 auth", "reasons": { "a": "Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. OAuth 2.0 with service accounts and IAM roles per project (30). The discovery document lists `access_token`, `oauth_token` and `key` as query parameters, so 10 off, as every Google API listing in this run (20 of 30). The data logging page says Google doesn't log any customer Cloud TTS text or audio (20). The service is stateless and keeps no content (15). Because it is stateless, Data Access audit logs don't apply, leaving admin activity only (5 of 15). Valid security.txt, Google's vulnerability reward programme, SOC 2 and ISO 27001 and public Cloud security bulletins, as on google-speech-to-text (20). Total 80.", "b": "Model reading of the checklist, with training and retention in place of least-privilege and injection lines. API keys can be restricted to resource read and write scopes, a key without the scope gets 403 insufficient_api_key_scope, `GET /v3/api_keys/self` reports a key's scope mode, and the docs cover rotation (30). The privacy policy (11 August 2026) and the terms (23 July 2026) allow training on user input, with an opt-out by email, and the security page excludes enterprise data by default, per the 10 October check, not re-read on 1 November (10). No retention period for voices or speech was found, deleted data stays in backups for 60 days, and voices can be deleted through the API (5). Each response carries an X-Request-Id used in usage and billing records, and `end_user_id` attributes usage per end user. Audit logs of user and admin actions are for enterprise customers (10 of 15). A valid security.txt (expires 31 December 2026, re-read 1 November), a disclosure policy with safe harbour, SOC 2 Type II stated on the security page with reports on request, and no bug bounty. The report was not read, so the certification counts as a vendor claim (14 of 20). Total 69." }, "scores": { "a": 80, "b": 69 } } ], "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "Google Cloud", "b": "HeyGen", "name": "Vendor" }, { "a": "no (local only)", "b": "https://api.heygen.com", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "OAuth", "b": "API key", "name": "Auth" }, { "a": "Pay per use", "b": "Pay per use", "name": "Pricing" }, { "a": "$10 per 1M tokens", "b": "not published", "name": "Price for text-to-speech" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "none", "b": "Closed service under HeyGen's Terms of Service (HeyGen Technology, Inc., last updated 23 July 2026).", "name": "Licence" }, { "a": "0", "b": "none", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2025-12-30", "b": "2026-10-20", "name": "Last release" }, { "a": "2026-09-02", "b": "2026-07-23", "name": "Terms last updated" }, { "a": "2026-10-01", "b": "2026-08-11", "name": "Privacy policy last updated" }, { "a": "yes", "b": "yes", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict automated access" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "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": "none", "b": "3.5/5 (4)", "name": "Agent reviews" } ], "faq": [ { "answer": "HeyGen Voice scores 73.6 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 4 of 7 scored categories. Google Cloud Text-to-Speech leads on reliability, security \u0026 auth and transparency \u0026 trust.", "question": "Which is better for AI agents, Google Cloud Text-to-Speech or HeyGen Voice?" }, { "answer": "Google Cloud Text-to-Speech uses an OAuth sign-in. HeyGen Voice needs an API key.", "question": "Do Google Cloud Text-to-Speech and HeyGen Voice need an API key?" }, { "answer": "No hosted endpoint is listed for Google Cloud Text-to-Speech. HeyGen Voice has a hosted endpoint at https://api.heygen.com.", "question": "Can an agent call Google Cloud Text-to-Speech and HeyGen Voice without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 85 against 75", "Security \u0026 auth, 80 against 69", "Transparency \u0026 trust, 87 against 66" ], "also": null, "goodFor": "Teams already on Google Cloud wanting many languages, SSML and an SLA.", "slug": "google-cloud-tts", "watchFor": "No release note since 30 December 2025, though a Gemini 3.1 TTS preview model is listed" }, { "aheadOn": [ "Schema \u0026 documentation, 97 against 80", "Agent ergonomics, 88 against 65", "Payments \u0026 pricing, 40 against 20", "Maintenance \u0026 community, 65 against 25" ], "also": [ "Agent-ready, a grade of BB or better", "A hosted endpoint, with nothing to install" ], "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": "30 requests a minute per workspace member on the speech endpoints by default, and Turbo Free's shared capacity can return 429 below that" } ], "history": { "google-cloud-tts": null, "heygen-voice": [ { "causes": [ "pricing", "product" ], "date": "2026-11-01", "delta": 2.5, "from": 71.1, "fromGrade": "BB", "to": 73.6, "toGrade": "BB" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.2, "from": 70.9, "fromGrade": "BB", "to": 71.1, "toGrade": "BB" }, { "causes": [ "evidence" ], "date": "2026-10-12", "delta": -0.4, "from": 71.3, "fromGrade": "BB", "to": 70.9, "toGrade": "BB" } ] }, "job": { "capability": "speech.tts", "name": "Text-to-speech" }, "others": [ { "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/azure-text-to-speech-vs-google-cloud-tts.json", "title": "Azure AI Speech text-to-speech vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-heygen-voice.json", "title": "Azure AI Speech text-to-speech vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/azure-text-to-speech-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts.json", "title": "Cartesia Sonic TTS API + MCP vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice.json", "title": "Cartesia Sonic TTS API + MCP vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/deepgram-tts-vs-google-cloud-tts.json", "title": "Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/deepgram-tts-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/deepgram-tts-vs-heygen-voice.json", "title": "Deepgram Text-to-Speech (Aura-2, Flux TTS) vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/deepgram-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-google-cloud-tts.json", "title": "ElevenLabs Text to Speech API + MCP vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-heygen-voice.json", "title": "ElevenLabs Text to Speech API + MCP vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/elevenlabs-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-google-cloud-tts.json", "title": "Fish Audio TTS API vs Google Cloud Text-to-Speech", "url": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-google-cloud-tts" }, { "json": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-heygen-voice.json", "title": "Fish Audio TTS API vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/fish-audio-tts-vs-heygen-voice" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-inworld-tts.json", "title": "Google Cloud Text-to-Speech vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-minimax-speech.json", "title": "Google Cloud Text-to-Speech vs MiniMax Speech (T2A)", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-minimax-speech" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-murf-tts.json", "title": "Google Cloud Text-to-Speech vs Murf TTS API + MCP", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-murf-tts" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-playht-tts.json", "title": "Google Cloud Text-to-Speech vs PlayHT Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-playht-tts" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-resemble-ai-tts.json", "title": "Google Cloud Text-to-Speech vs Resemble AI Text-to-Speech API", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-resemble-ai-tts" }, { "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-rime-tts.json", "title": "Google Cloud Text-to-Speech vs Rime TTS API + MCP", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-rime-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/google-cloud-tts-vs-soniox-tts.json", "title": "Google Cloud Text-to-Speech vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts.json", "title": "HeyGen Voice vs Inworld Realtime TTS-2", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts" }, { "json": "https://www.anchorterminal.com/compare/heygen-voice-vs-minimax-speech.json", "title": "HeyGen Voice vs MiniMax Speech (T2A)", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-minimax-speech" }, { "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/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/heygen-voice-vs-soniox-tts.json", "title": "HeyGen Voice vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts" } ], "panel": null, "scores": [ { "by": 10, "edge": "google-cloud-tts", "google-cloud-tts": 85, "heygen-voice": 75, "key": "reliability", "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 17, "edge": "heygen-voice", "google-cloud-tts": 80, "heygen-voice": 97, "key": "schema", "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 23, "edge": "heygen-voice", "google-cloud-tts": 65, "heygen-voice": 88, "key": "ergonomics", "name": "Agent ergonomics", "weight": 13 }, { "by": 11, "edge": "google-cloud-tts", "google-cloud-tts": 80, "heygen-voice": 69, "key": "security", "name": "Security \u0026 auth", "weight": 14 }, { "by": 20, "edge": "heygen-voice", "google-cloud-tts": 20, "heygen-voice": 40, "key": "payments", "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 40, "edge": "heygen-voice", "google-cloud-tts": 25, "heygen-voice": 65, "key": "maintenance", "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 21, "edge": "google-cloud-tts", "google-cloud-tts": 87, "heygen-voice": 66, "key": "transparency", "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "HeyGen Voice scores 73.6 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 4 of 7 scored categories. Google Cloud Text-to-Speech leads on reliability, security \u0026 auth and transparency \u0026 trust. Both do text-to-speech.", "tasks": [ { "a": "$0.04 to $1.44", "b": "$0.13 to $0.27", "cheaper": "google-cloud-tts", "task": "Narrate a 9,000-character script", "what": "about 1,500 words" } ], "tutorials": [], "verdicts": { "google-cloud-tts": "Cloud TTS has a typed discovery document, a 99.9 per cent SLA, no logging of text or audio, and voices from $4 to $160 per million characters. Its release notes stop at 30 December 2025, the newest Gemini TTS models ship only on the Agent Platform API, and tokens can travel in the URL.", "heygen-voice": "HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, a choice of audio formats and published prices of $30 per million characters, $15 on Turbo. Turbo Free costs nothing until 30 November 2026. Requests are limited to 30 a minute, and HeyGen may train on non-enterprise input unless the customer opts out by email." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice", "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice.min.md" }, "markdown": "HeyGen Voice scores 73.6 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 4 of 7 scored categories. Google Cloud Text-to-Speech leads on reliability, security \u0026 auth and transparency \u0026 trust. Both do text-to-speech.\n\n- Google Cloud Text-to-Speech: grade B, 66.9/100, rank #351 of 1510. Markdown https://www.anchorterminal.com/tools/google-cloud-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/google-cloud-tts.json\n- HeyGen Voice: grade BB, 73.6/100, rank #103 of 1510. Markdown https://www.anchorterminal.com/tools/heygen-voice.md · JSON https://www.anchorterminal.com/api/v1/tools/heygen-voice.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### Google Cloud Text-to-Speech (B)\n\nGood for: Teams already on Google Cloud wanting many languages, SSML and an SLA.\n\nAhead on:\n- Reliability, 85 against 75\n- Security \u0026 auth, 80 against 69\n- Transparency \u0026 trust, 87 against 66\n\nWatch for: No release note since 30 December 2025, though a Gemini 3.1 TTS preview model is listed\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, 97 against 80\n- Agent ergonomics, 88 against 65\n- Payments \u0026 pricing, 40 against 20\n- Maintenance \u0026 community, 65 against 25\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n- A hosted endpoint, with nothing to install\n\nWatch for: 30 requests a minute per workspace member on the speech endpoints by default, and Turbo Free's shared capacity can return 429 below that\n\n\n## Why the edge\n\n### Maintenance \u0026 community: HeyGen Voice +40\n\n- Google Cloud Text-to-Speech (25): Read as a model. The newest release note is still 30 December 2025 (Chirp 3 HD in yue-HK), 311 days ago, and `gemini-3.1-flash-tts-preview` appears on the Gemini-TTS page with no dated note (0). In the 90 days from 8 August the Python client shipped 2.38.0 on 1 October, whose only change declares Python 3.15 support, which counts half and can't set the recency line (0). Release notes, a public issue tracker and paid support (10 of 15). Official client libraries, Python at 2.38.0 and Node at 7.2.0 (10 of 15). Package CI not checked (5 of 10). Total 25.\n- HeyGen Voice (65): Read as a model. The changelog's newest voice entry, speech to speech, is in the RSS feed on 20 October 2026 (30). Seven voice entries between 9 and 20 October alone, instant voices, Turbo, public voices with timestamps, previews, voices from an image, professional voices without a language and speech to speech, and dated sunsets elsewhere in the API, v1 and v2 on 31 October 2026, announced in April (20). Public changelog with RSS and a developer Discord. Answers were not sampled (10 of 15). No official SDK. HeyGen ships a CLI and agent skills (5 of 15). No package health record was read (0). Total 65.\n\n### Agent ergonomics: HeyGen Voice +23\n\n- Google Cloud Text-to-Speech (65): API reading of the checklist. Audio returns Base64 in JSON or streams over gRPC, with encoding, sample rate and timepoints selectable (15 of 25). `voices.list` filters by language code with no paging, and operations list with page tokens (15 of 20). Standard gRPC status codes with messages, generic rather than TTS-specific (15 of 20). Synthesis is stateless and long audio runs as an operation, with no idempotency key (10 of 20). A first call needs a project, billing, OAuth credentials and a voice, and Cloud Storage for long audio. Official client libraries in many languages, of which Python and Node were checked (10 of 15). Total 65.\n- HeyGen Voice (88): API reading of the checklist. The completed response is a URL and a duration, streaming returns WAV parts as they are made, and timestamps come only when asked. Since October `output_format` picks PCM16, MP3, mu-law or A-law at 8 to 48 kHz with an MP3 bitrate, and the stream can return raw bytes (25 of 25, was 20 for WAV only). Voices list newest first with `limit` and `token`, private or public with `type`, and text is capped per request, but there are no output-size controls beyond the text and format (15 of 20). Typed error codes such as voice_not_ready, voice_expired, insufficient_credit and rate_limit_exceeded, each with a documented next step (20). Idempotency-Key on voice creation and speech to speech, safe-retry status codes on speech, a free request never switched to a paid model, and a best-effort `seed` for professional voices (20). Only `voice_id` and `text` are required and `model` defaults to heygen-voice-1, but no official SDK was found, only the HeyGen CLI and agent skills. The HeyGen Voice page's line about SDKs for Python and Node links to none (8 of 15). Total 88.\n\n### Transparency \u0026 trust: Google Cloud Text-to-Speech +21\n\n- Google Cloud Text-to-Speech (87): Closed service under the Google Cloud terms, with Apache-2.0 clients (15). The data logging page, the terms and the privacy notice agree that TTS text and audio aren't logged, and a DPA and sub-processor list exist, as read for google-speech-to-text (25 of 30). Release notes mark preview and GA, and the Cloud terms carry notice before a GA capability is discontinued, but Gemini-TTS is moving to the Agent Platform API with no dated notice for the Cloud TTS models (15 of 20). Regional endpoints (global, us, eu and others) and a public sub-processor list (20). Total 75.\n- HeyGen Voice (66): Closed service with terms dated 23 July 2026, per the 10 October check. Paid plans own their output, and free-plan output is limited to non-commercial use (15). Privacy policy, terms and security page agree that non-enterprise input can train models with an opt-out by email, and differ on the entity name (HeyGen Technology Inc. and HeyGen, Inc.). No retention period for voice or speech data (12 of 30). Dated deprecation notices in the changelog, such as the v1 and v2 sunset on 31 October 2026, and an end date for Turbo Free with a promise of notice before it changes, but no notice yet for this model (15 of 20). Subprocessors are listed on the security portal, which was not read, and the privacy policy says data may be processed in the United States (10 of 20). Total 52.\n\n### Payments \u0026 pricing: HeyGen Voice +20\n\n- Google Cloud Text-to-Speech (20): No x402, MPP or L402 (0). Per-character and per-token prices for every voice family published without a login (20). Monthly free characters (1 million for Chirp 3 HD, 4 million for Standard and WaveNet) need billing enabled, which needs a card (0). A person creates a project and billing account in a browser (0). Total 20.\n- HeyGen Voice (40): No x402, MPP or L402 in the llms.txt, the OpenAPI file or the voice pages (0). The HeyGen Voice page publishes API speech at $30 per million characters on heygen-voice-1, $15 on Turbo and speech to speech at $0.12 a minute, without a login (20). `heygen-voice-1-turbo-free` is free until 30 November 2026 with a free API key and no credit balance, for public and instant voices, under shared capacity. Neither the docs nor the HeyGen Voice page say whether the free key needs a card at sign-up, and \"no credit balance\" isn't the same statement. HeyGen's pricing FAQ says the web Free plan needs no card, but doesn't say that covers API keys, and the API dashboard's host couldn't be read. So half, the reading listings with unstated card terms get (anthropic-api, zep, and fish-audio-voice-cloning for its free model to the same date), until it ends (10). Stripe Projects lists heygen/api, which lets an agent create the account and receive a key through the operator's Stripe login and saved payment method. A person still has to log in to Stripe once (10). 0+20+10+10 = 40.\n\n### Schema \u0026 documentation: HeyGen Voice +17\n\n- Google Cloud Text-to-Speech (80): Discovery document revision 20260827 with typed methods and 26 schemas, and protocol buffers for gRPC (25). No llms.txt found (0). The Chirp 3 HD and Gemini-TTS pages say which voices suit which use and list formats and limits, but the reference doesn't say when to choose streaming or long audio (15 of 20). Typed messages with enums for encoding and gender and required fields (15). Samples in several languages, standard status codes with little method-specific error detail (10 of 15). Versioned v1 and v1beta1 with dated release notes (15). Total 80.\n- HeyGen Voice (97): OpenAPI 3.1 file at developers.heygen.com/openapi/external-api.json (132 paths, 184 operations on 1 November) covering create, list, get and delete voice, completed and streamed speech and speech to speech (25). llms.txt with a Markdown twin of every page (10). Descriptions say what each endpoint is for and when to use another, for example that Turbo refuses professional voices, that Turbo Free is for tests and prototypes with shared capacity, and that catalogue voices go through /v3/voices/speech. Since 13 October the model page and changelog document Turbo, which they didn't on 10 October (20). Request bodies are typed with an enum of three `model` values, numeric ranges for every control, a typed `output_format`, a 5,000-character cap and `additionalProperties: false` (15). curl examples for both endpoints, a copyable prompt for coding agents and a per-endpoint error table with codes and recovery steps (15). Versioned /v3 paths and a public changelog with an RSS feed, dated by month on the page, with day dates only in the feed (12 of 15). Total 97.\n\n### Security \u0026 auth: Google Cloud Text-to-Speech +11\n\n- Google Cloud Text-to-Speech (80): Model reading of the checklist, with training and retention in place of the least-privilege and injection lines. OAuth 2.0 with service accounts and IAM roles per project (30). The discovery document lists `access_token`, `oauth_token` and `key` as query parameters, so 10 off, as every Google API listing in this run (20 of 30). The data logging page says Google doesn't log any customer Cloud TTS text or audio (20). The service is stateless and keeps no content (15). Because it is stateless, Data Access audit logs don't apply, leaving admin activity only (5 of 15). Valid security.txt, Google's vulnerability reward programme, SOC 2 and ISO 27001 and public Cloud security bulletins, as on google-speech-to-text (20). Total 80.\n- HeyGen Voice (69): Model reading of the checklist, with training and retention in place of least-privilege and injection lines. API keys can be restricted to resource read and write scopes, a key without the scope gets 403 insufficient_api_key_scope, `GET /v3/api_keys/self` reports a key's scope mode, and the docs cover rotation (30). The privacy policy (11 August 2026) and the terms (23 July 2026) allow training on user input, with an opt-out by email, and the security page excludes enterprise data by default, per the 10 October check, not re-read on 1 November (10). No retention period for voices or speech was found, deleted data stays in backups for 60 days, and voices can be deleted through the API (5). Each response carries an X-Request-Id used in usage and billing records, and `end_user_id` attributes usage per end user. Audit logs of user and admin actions are for enterprise customers (10 of 15). A valid security.txt (expires 31 December 2026, re-read 1 November), a disclosure policy with safe harbour, SOC 2 Type II stated on the security page with reports on request, and no bug bounty. The report was not read, so the certification counts as a vendor claim (14 of 20). Total 69.\n\n## Score by category\n\n| Category | Weight | Google Cloud Text-to-Speech | HeyGen Voice | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 85 | 75 | Google Cloud Text-to-Speech +10 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 80 | 97 | HeyGen Voice +17 |\n| Agent ergonomics | 13% (16.2 this run) | 65 | 88 | HeyGen Voice +23 |\n| Security \u0026 auth | 14% (17.5 this run) | 80 | 69 | Google Cloud Text-to-Speech +11 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 20 | 40 | HeyGen Voice +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 25 | 65 | HeyGen Voice +40 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 87 | 66 | Google Cloud Text-to-Speech +21 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **66.9 · B** | **73.6 · BB** | |\n\n## Facts side by side\n\n| Fact | Google Cloud Text-to-Speech | HeyGen Voice |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Google Cloud | HeyGen |\n| Hosted endpoint | no (local only) | `https://api.heygen.com` |\n| Transports | HTTP | HTTP |\n| Auth | OAuth | API key |\n| Pricing | Pay per use | Pay per use |\n| Price for text-to-speech | $10 per 1M tokens | not published |\n| x402 | no | no |\n| Licence | none | Closed service under HeyGen's Terms of Service (HeyGen Technology, Inc., last updated 23 July 2026). |\n| Tools exposed | 0 | none |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2025-12-30 | 2026-10-20 |\n| Terms last updated | 2026-09-02 | 2026-07-23 |\n| Privacy policy last updated | 2026-10-01 | 2026-08-11 |\n| Customer content may train models | yes | yes |\n| Terms restrict automated access | not found in the text | yes |\n| Terms restrict benchmarking | not found in the text | yes |\n| Terms or service can change without notice | not found in the text | yes |\n| Arbitration or class-action waiver | not found in the text | yes |\n| Agent reviews | none | 3.5/5 (4) |\n\n## What the same task costs\n\n| Task | Google Cloud Text-to-Speech | HeyGen Voice |\n| --- | --- | --- |\n| Narrate a 9,000-character script | $0.04 to $1.44 | $0.13 to $0.27 |\n\n## How the scores have moved\n\n### Google Cloud Text-to-Speech\n\nNo score change since it was listed.\n\n### HeyGen Voice\n\n- +2.5 on 1 November 2026: pricing, product\n- +0.2 on 27 October 2026: checklist\n- -0.4 on 12 October 2026: new evidence\n\n## Verdicts\n\n**Google Cloud Text-to-Speech.** Cloud TTS has a typed discovery document, a 99.9 per cent SLA, no logging of text or audio, and voices from $4 to $160 per million characters. Its release notes stop at 30 December 2025, the newest Gemini TTS models ship only on the Agent Platform API, and tokens can travel in the URL.\n\n**HeyGen Voice.** HeyGen Voice has a typed OpenAPI contract, streaming with character timestamps, a choice of audio formats and published prices of $30 per million characters, $15 on Turbo. Turbo Free costs nothing until 30 November 2026. Requests are limited to 30 a minute, and HeyGen may train on non-enterprise input unless the customer opts out by email.\n\n## Before you call either\n\n### Google Cloud Text-to-Speech\n\n1. Send OAuth tokens in the Authorization header, never as `access_token` or `key` in the URL\n2. Use `synthesizeLongAudio` with a Cloud Storage bucket for long text, and `text:synthesize` for short replies\n3. Pick Chirp 3 HD for natural voices with SSML, and Gemini-TTS when the delivery needs prompt steering\n4. Check whether the Gemini TTS model you want is on the Cloud TTS API or only on the Agent Platform API\n5. Stay within 200 requests a minute on Chirp 3 voices, which have their own quota\n\n### HeyGen Voice\n\n1. Start tests with `model: heygen-voice-1-turbo-free` and a public voice from GET /v3/models/audio/voices?type=public. It never falls back to a paid model\n2. Create a clone with POST /v3/models/audio/voices and `mode`, then poll GET /v3/models/audio/voices/{voice_id} until `status` is ACTIVE before calling speech\n3. Send `expressiveness_boost` only for instant voices. Professional voices reject it, and instant voices ignore `seed`, `speed`, `pitch_shift` and `pitch_variance`\n4. On a 429 without Retry-After, back off exponentially. Capacity 429s carry no header\n5. Use POST /v3/voices/speech for catalogue or designed voices. It is a different endpoint and price\n\n## Questions\n\n### Which is better for AI agents, Google Cloud Text-to-Speech or HeyGen Voice?\n\nHeyGen Voice scores 73.6 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 4 of 7 scored categories. Google Cloud Text-to-Speech leads on reliability, security \u0026 auth and transparency \u0026 trust.\n\n### Do Google Cloud Text-to-Speech and HeyGen Voice need an API key?\n\nGoogle Cloud Text-to-Speech uses an OAuth sign-in. HeyGen Voice needs an API key.\n\n### Can an agent call Google Cloud Text-to-Speech and HeyGen Voice without installing anything?\n\nNo hosted endpoint is listed for Google Cloud Text-to-Speech. HeyGen Voice has a hosted endpoint at https://api.heygen.com.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice.json, and with the fewest tokens: https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"google-cloud-tts\", \"b\": \"heygen-voice\"}`. From a terminal: `anchor compare google-cloud-tts heygen-voice`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/google-cloud-tts.json and https://www.anchorterminal.com/api/v1/tools/heygen-voice.json\n\n## Other comparisons with Google Cloud Text-to-Speech or HeyGen Voice\n\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- [Azure AI Speech text-to-speech vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-google-cloud-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- [Cartesia Sonic TTS API + MCP vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts.md)\n- [Cartesia Sonic TTS API + MCP vs HeyGen Voice](https://www.anchorterminal.com/compare/cartesia-tts-vs-heygen-voice.md)\n- [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/deepgram-tts-vs-google-cloud-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- [ElevenLabs Text to Speech API + MCP vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-google-cloud-tts.md)\n- [ElevenLabs Text to Speech API + MCP vs HeyGen Voice](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-heygen-voice.md)\n- [Fish Audio TTS API vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/fish-audio-tts-vs-google-cloud-tts.md)\n- [Fish Audio TTS API vs HeyGen Voice](https://www.anchorterminal.com/compare/fish-audio-tts-vs-heygen-voice.md)\n- [Google Cloud Text-to-Speech vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/google-cloud-tts-vs-inworld-tts.md)\n- [Google Cloud Text-to-Speech vs MiniMax Speech (T2A)](https://www.anchorterminal.com/compare/google-cloud-tts-vs-minimax-speech.md)\n- [Google Cloud Text-to-Speech vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/google-cloud-tts-vs-murf-tts.md)\n- [Google Cloud Text-to-Speech vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/google-cloud-tts-vs-playht-tts.md)\n- [Google Cloud Text-to-Speech vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/google-cloud-tts-vs-resemble-ai-tts.md)\n- [Google Cloud Text-to-Speech vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/google-cloud-tts-vs-rime-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- [Google Cloud Text-to-Speech vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.md)\n- [HeyGen Voice vs Inworld Realtime TTS-2](https://www.anchorterminal.com/compare/heygen-voice-vs-inworld-tts.md)\n- [HeyGen Voice vs MiniMax Speech (T2A)](https://www.anchorterminal.com/compare/heygen-voice-vs-minimax-speech.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- [HeyGen Voice vs Smallest.ai Lightning TTS](https://www.anchorterminal.com/compare/heygen-voice-vs-smallest-lightning-tts.md)\n- [HeyGen Voice vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/heygen-voice-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": "Google Cloud Text-to-Speech vs HeyGen Voice", "url": "" } ], "description": "HeyGen Voice scores 73.6 (BB) to Google Cloud Text-to-Speech's 66.9 (B) for text-to-speech. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Google Cloud Text-to-Speech B 66.9", "HeyGen Voice BB 73.6", "scores" ], "h1": "Google Cloud Text-to-Speech vs HeyGen Voice", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/google-cloud-tts-vs-heygen-voice", "published": "2026-10-01", "section": "tools", "title": "Google Cloud Text-to-Speech vs HeyGen Voice for AI agents (2026)", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-heygen-voice" }, "tokens": { "markdown": 5450, "slim": 3230 }, "version": 1 }