{ "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": 350, "ranked": true, "rankOf": 1486, "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": "Soniox Text-to-Speech scores 70.5 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 5 of 7 scored categories. Google Cloud Text-to-Speech leads on transparency \u0026 trust.", "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", "dns": "soniox-tts.grade.anchorterminal.com", "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, with permissions per resource (TTS real-time, cloned voices, usage, models, temporary keys), 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`, where the key goes in the Authorization header or the protocols list; `api_key` in the config message works until 15 January 2027. Regional hosts for the EU, Japan and India. An organisation API key can create and delete project keys.", "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://docs.soniox.com/tts/get-started", "llmsTxt": "https://docs.soniox.com/llms.txt", "openapi": "https://docs.soniox.com/openapi.yaml", "capabilities": [ "speech.tts", "speech.streaming", "speech.voices", "speech.languages" ], "tags": [ "hosted", "closed-source", "python", "typescript", "llms-txt", "streaming", "openapi" ], "lastRelease": "2026-10-02", "graded": true, "anchor": { "graded": true, "score": 70.5, "grade": "BB", "agentReady": true, "rank": 198, "ranked": true, "rankOf": 1486, "categoryRank": 6, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 78, "maintenance": 63, "payments": 20, "reliability": 87, "schema": 85, "security": 87, "transparency": 73 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-02" }, "negative": -3, "negativeNotes": [ "2026-10-02. Python SDK `soniox` 2.10.0, a minor release, lists under Removed `build_payload()` and `api_key` on `RealtimeSTTConfig` and `RealtimeTTSConfig` (reading `config.api_key` now raises `AttributeError`), and makes the API key a required argument of the realtime session classes. No earlier deprecation was found in the changelog. A breaking change in a minor release without notice takes 3 (https://github.com/soniox/soniox-python/blob/main/CHANGELOG.md)." ], "verdict": "Content is not stored by default or used for training, keys carry per-resource permissions, an OpenAPI file covers the REST endpoint, and no TTS incident was posted in the 90 days to 2 November. Audio stops at two minutes per request, and Python SDK 2.10.0 removed public interfaces in a minor release without notice.", "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", "API keys carry per-resource permissions, and an organisation API creates and deletes them", "OpenAPI 3.1.0 file with per-status error messages, plus one `error_type` format across surfaces", "Separate TTS REST and TTS Real-time status components in four regions, no TTS incident since 4 August", "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", "Python SDK 2.10.0 removed public interfaces in a minor release with no earlier deprecation", "No free credits for new accounts, and no Retry-After on 429" ], "agentNotes": [ "Split text so each request stays under 2 minutes of audio, or it truncates.", "Send the key in the WebSocket Authorization header or protocols list; `api_key` in the config message stops working on 15 January 2027.", "Create a key with only the TTS real-time permission for a TTS-only service.", "Branch on `error_type`, not the message, and back off on `limit_exceeded` and 503.", "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": "BB", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 70.5 } ], "editorialScores": { "ergonomics": 78, "maintenance": 63, "payments": 20, "reliability": 87, "schema": 85, "security": 87, "transparency": 64 }, "provenanceScore": 81, "checked": { "categories": { "ergonomics": "2026-11-02", "maintenance": "2026-11-02", "payments": "2026-11-02", "reliability": "2026-11-02", "schema": "2026-11-02", "security": "2026-11-02", "transparency": "2026-11-02" }, "last": "2026-11-02", "lastMoved": "2026-11-02", "oldest": "2026-11-02", "stale": false, "staleAfterDays": 90 } }, "connect": { "http": "curl 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://docs.soniox.com/tts/models", "securityTxt": "none", "checked": "2026-11-02", "notes": [ "Terms and privacy policy last updated 2026-06-29. The company address is Foster City, California", "The docs moved to docs.soniox.com (soniox.com/docs answers 308 to it). soniox.com/.well-known/security.txt answers 404, re-read on 2 November 2026." ], "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": "2026-11-07T18:20:55.897086637Z", "lastOk": true, "lastStatus": 404, "lastMs": 190, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 278, "p95ms24h": 410, "samples24h": 239, "samples30d": 7910, "days": [ { "date": "2026-10-07", "probes": 272, "ok": 272 }, { "date": "2026-10-08", "probes": 268, "ok": 268 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 247 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 249 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 255 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 253 }, { "date": "2026-10-22", "probes": 253, "ok": 253 }, { "date": "2026-10-23", "probes": 248, "ok": 248 }, { "date": "2026-10-24", "probes": 251, "ok": 251 }, { "date": "2026-10-25", "probes": 250, "ok": 250 }, { "date": "2026-10-26", "probes": 252, "ok": 252 }, { "date": "2026-10-27", "probes": 249, "ok": 249 }, { "date": "2026-10-28", "probes": 250, "ok": 250 }, { "date": "2026-10-29", "probes": 249, "ok": 249 }, { "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": 241 }, { "date": "2026-11-07", "probes": 187, "ok": 187 } ] }, "vendorStatus": { "page": "https://status.soniox.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-06T23:08:59.743605756Z" }, "versions": [ { "registry": "npm", "name": "@soniox/node", "version": "2.5.0", "seenAt": "2026-11-07T00:07:15.417491279Z" }, { "registry": "pypi", "name": "soniox", "version": "2.11.0", "released": "2026-11-03", "seenAt": "2026-11-07T00:07:15.892497401Z" } ], "githubStars": 13, "npmWeekly": 39562, "pypiWeekly": 214784, "securityTxt": { "url": "https://soniox.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:56.119851929Z" }, "llmsTxt": { "url": "https://docs.soniox.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:34:00.570653144Z" }, "domain": { "domain": "soniox.com", "registered": "2020-03-23", "source": "https://rdap.verisign.com/com/v1/domain/soniox.com", "checkedAt": "2026-11-01T14:17:24.699916178Z" }, "pages": [ { "url": "https://docs.soniox.com/tts/models", "kind": "changelog", "status": 304, "checkedAt": "2026-11-07T14:08:11.186731463Z", "changedAt": "2026-11-04T08:22:35.509459829Z", "fingerprint": "46e0b251436a" }, { "url": "https://docs.soniox.com/guides/migrate-websocket-authentication", "kind": "deprecations", "status": 304, "checkedAt": "2026-11-07T14:08:07.180271884Z", "changedAt": "2026-11-04T08:22:33.010622101Z", "fingerprint": "c9942af1673f" }, { "url": "https://soniox.com/docs/tts/models", "kind": "deprecations", "status": 304, "checkedAt": "2026-11-07T14:20:19.913199501Z", "changedAt": "2026-11-04T08:33:13.362017698Z", "fingerprint": "46e0b251436a" } ], "github": { "repo": "soniox/soniox-python", "checkedAt": "2026-11-02T09:26:52.131649771Z", "stars": 13, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-02T13:42:01Z", "openIssues": 0, "openPRs": 1, "issuesOpened90d": 0, "issuesClosed90d": 0, "prsMerged90d": 0, "replies": { "sampled": 1, "unanswered": 0, "medianDays": 10 } }, "updatedAt": "2026-11-07T18:20:55.897086637Z" } }, "edges": [ { "by": 38, "category": "maintenance", "leads": "soniox-tts", "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, on the lines deepgram-tts and cartesia-tts use for hosted speech models (recency 30, dated releases 10, deprecation notice 10, support 15, issues 10, SDKs 15, health 10). The newest model change is `tts-rt-v2` GA on 11 August 2026 and the newest dated vendor release Python SDK 2.10.0 on 2 October, 31 days before 2 November (20). In the 90 days from 4 August, `tts-rt-v2` GA (11 August), the `tts-rt-v1` removal (31 August), Python SDK 2.9.0 (11 August) and 2.10.0 (2 October), and the JavaScript SDK tag v2026.08.11 (10 August, counted half) (10; was 0). `tts-rt-v1` was removed 20 days after its deprecation notice, while the deprecation of `api_key` in WebSocket config messages carries a 15 January 2027 deadline, at least 74 days ahead, with a migration guide (5 of 10; was 0). The models page and a support channel, untested (5 of 15). SDK issues couldn't be read because GitHub's pages answered 403 (3 of 10). SDKs for Python, Node, the web and React (15). The Python SDK has a test suite and lock file, but its CI file sits in `.github/` rather than `.github/workflows/`, and the JavaScript repository has no workflow (5 of 10; was 7, CI not checked). 20 + 10 + 5 + 5 + 3 + 15 + 5 = 63." }, "scores": { "a": 25, "b": 63 } }, { "by": 14, "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 under terms updated 2026-06-29, Python SDK under Apache-2.0 (15). The security page, the terms and the TTS docs agree on no storage and no training, with async data deleted after 30 days (25 of 30). Model removals are dated on the models page with 20 days' notice for v1, and the WebSocket authentication change is dated to 15 January 2027 with a migration guide, but there is no written policy (12 of 20; was 10). Regional hosts in the US, EU, Japan and India and a data residency page, no sub-processor list found (12 of 20). 15 + 25 + 12 + 12 = 64." }, "scores": { "a": 87, "b": 73 } }, { "by": 13, "category": "ergonomics", "leads": "soniox-tts", "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. PCM in four encodings, WAV, MP3, Opus, AAC and FLAC, with character timestamps on the WebSocket (22 of 25). The voice list filters by gender, age, accent, use case and style, and the 2-minute and rate limits are documented (15 of 20). Machine-readable `error_type` values an agent can branch on (20). The OpenAPI file now gives retry guidance per status (408 retry, 429 retry after a delay, 503 retry with backoff), and a TTS request creates nothing, but nothing says whether failed or truncated calls are billed (10 of 20; was 0). Model, language, voice, format and text are all set per request. SDKs for Python, Node, the web and React (11 of 15). 22 + 15 + 20 + 10 + 11 = 78." }, "scores": { "a": 65, "b": 78 } }, { "by": 7, "category": "security", "leads": "soniox-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. Project API keys now carry permissions per resource (TTS real-time, cloned voices, usage, model listing, temporary keys, with read and write levels), a missing permission returns 403 `permission_denied`, and an organisation API key can list, create and delete project keys. Temporary keys for browsers expire and are scoped to a `usage_type` (30; was 25). Soniox says audio and text are never used to improve its models (20). Nothing is stored unless you ask, and logs carry no content (15). Per-request usage logs record model, duration, tokens and the client reference id, readable through `GET /v1/usage-logs`, as soniox-stt reads them (10 of 15; was 5). SOC 2 Type 2, ISO/IEC 27001:2022 and HIPAA listed on the security page. The Python SDK's SECURITY.md (since May 2026) gives a disclosure route by email, GitHub, a maintainer or Discord. soniox.com/.well-known/security.txt answers 404 and no bug bounty was found (12 of 20; was 10). 30 + 20 + 15 + 10 + 12 = 87." }, "scores": { "a": 80, "b": 87 } }, { "by": 5, "category": "schema", "leads": "soniox-tts", "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": "Soniox now publishes an OpenAPI 3.1.0 file at docs.soniox.com/openapi.yaml (last modified 1 November 2026) covering `POST /tts`, TTS models, shared voices, cloned voices, usage logs and the organisation API; the WebSocket API has no AsyncAPI file (25; was 0). llms.txt and `.mdx` pages, now on docs.soniox.com (10). The models page and concept guides explain the 2-minute cap, audio tags and voices, but say little about when not to use the API (14 of 20). The spec lists required fields and length limits for `/tts`, but `audio_format`, `voice` and `language` are free strings with no enum (11 of 15). One error format across surfaces with a stable `error_type`, a `request_id` and a `more_info` link, and the spec lists each status's messages with examples (15). Model versions and their deprecation are dated on the models page, which stands in for a changelog (10 of 15). 25 + 10 + 14 + 11 + 15 + 10 = 85." }, "scores": { "a": 80, "b": 85 } } ], "facts": [ { "a": "Model API", "b": "Model API", "name": "Kind" }, { "a": "Google Cloud", "b": "Soniox", "name": "Vendor" }, { "a": "no (local only)", "b": "https://tts-rt.soniox.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": "$0.0117 per minute of audio", "name": "Price for text-to-speech" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "none", "b": "Apache-2.0 (Python SDK)", "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": "2026-10-02", "name": "Last release" }, { "a": "2026-09-02", "b": "2026-06-29", "name": "Terms last updated" }, { "a": "2026-10-01", "b": "2026-06-29", "name": "Privacy policy last updated" }, { "a": "yes", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "not found in the text", "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": "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": "Soniox Text-to-Speech scores 70.5 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 5 of 7 scored categories. Google Cloud Text-to-Speech leads on transparency \u0026 trust.", "question": "Which is better for AI agents, Google Cloud Text-to-Speech or Soniox Text-to-Speech?" }, { "answer": "Google Cloud Text-to-Speech uses an OAuth sign-in. Soniox Text-to-Speech needs an API key.", "question": "Do Google Cloud Text-to-Speech and Soniox Text-to-Speech need an API key?" }, { "answer": "No hosted endpoint is listed for Google Cloud Text-to-Speech. Soniox Text-to-Speech has a hosted endpoint at https://tts-rt.soniox.com.", "question": "Can an agent call Google Cloud Text-to-Speech and Soniox Text-to-Speech without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Transparency \u0026 trust, 87 against 73" ], "also": [ "No incidents deducted, where Soniox Text-to-Speech loses 3 points for them" ], "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, 85 against 80", "Agent ergonomics, 78 against 65", "Security \u0026 auth, 87 against 80", "Maintenance \u0026 community, 63 against 25" ], "also": [ "Agent-ready, a grade of BB or better", "A hosted endpoint, with nothing to install" ], "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" } ], "history": { "google-cloud-tts": null, "soniox-tts": [ { "causes": [ "product", "evidence", "event" ], "date": "2026-11-02", "delta": 6.8, "from": 63.7, "fromGrade": "B", "to": 70.5, "toGrade": "BB" }, { "causes": [ "method" ], "date": "2026-10-08", "delta": -0.2, "from": 63.9, "fromGrade": "B", "to": 63.7, "toGrade": "B" } ] }, "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-soniox-tts.json", "title": "Amazon Polly vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts" }, { "json": 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"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-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/google-cloud-tts-vs-heygen-voice.json", "title": "Google Cloud Text-to-Speech vs HeyGen Voice", "url": "https://www.anchorterminal.com/compare/google-cloud-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/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" }, { "json": "https://www.anchorterminal.com/compare/inworld-tts-vs-soniox-tts.json", "title": "Inworld Realtime TTS-2 vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/inworld-tts-vs-soniox-tts" }, { "json": "https://www.anchorterminal.com/compare/minimax-speech-vs-soniox-tts.json", "title": "MiniMax Speech (T2A) vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/minimax-speech-vs-soniox-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" }, { "json": "https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts.json", "title": "Smallest.ai Lightning TTS vs Soniox Text-to-Speech", "url": "https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts" } ], "panel": null, "scores": [ { "by": 2, "edge": "soniox-tts", "google-cloud-tts": 85, "key": "reliability", "name": "Reliability", "soniox-tts": 87, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 5, "edge": "soniox-tts", "google-cloud-tts": 80, "key": "schema", "name": "Schema \u0026 documentation", "soniox-tts": 85, "weight": 13 }, { "by": 13, "edge": "soniox-tts", "google-cloud-tts": 65, "key": "ergonomics", "name": "Agent ergonomics", "soniox-tts": 78, "weight": 13 }, { "by": 7, "edge": "soniox-tts", "google-cloud-tts": 80, "key": "security", "name": "Security \u0026 auth", "soniox-tts": 87, "weight": 14 }, { "by": 0, "edge": "", "google-cloud-tts": 20, "key": "payments", "name": "Payments \u0026 pricing", "soniox-tts": 20, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 38, "edge": "soniox-tts", "google-cloud-tts": 25, "key": "maintenance", "name": "Maintenance \u0026 community", "soniox-tts": 63, "weight": 7 }, { "by": 14, "edge": "google-cloud-tts", "google-cloud-tts": 87, "key": "transparency", "name": "Transparency \u0026 trust", "soniox-tts": 73, "weight": 7 } ], "summary": "Soniox Text-to-Speech scores 70.5 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 5 of 7 scored categories. Google Cloud Text-to-Speech leads on transparency \u0026 trust. Both do text-to-speech.", "tasks": null, "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.", "soniox-tts": "Content is not stored by default or used for training, keys carry per-resource permissions, an OpenAPI file covers the REST endpoint, and no TTS incident was posted in the 90 days to 2 November. Audio stops at two minutes per request, and Python SDK 2.10.0 removed public interfaces in a minor release without notice." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts", "json": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.min.md" }, "markdown": "Soniox Text-to-Speech scores 70.5 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 5 of 7 scored categories. Google Cloud Text-to-Speech leads on transparency \u0026 trust. Both do text-to-speech.\n\n- Google Cloud Text-to-Speech: grade B, 66.9/100, rank #350 of 1486. Markdown https://www.anchorterminal.com/tools/google-cloud-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/google-cloud-tts.json\n- Soniox Text-to-Speech: grade BB, 70.5/100, rank #198 of 1486. 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 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- Transparency \u0026 trust, 87 against 73\n\nAlso in its favour:\n- No incidents deducted, where Soniox Text-to-Speech loses 3 points for them\n\nWatch for: No release note since 30 December 2025, though a Gemini 3.1 TTS preview model is listed\n\n### Soniox Text-to-Speech (BB)\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- Schema \u0026 documentation, 85 against 80\n- Agent ergonomics, 78 against 65\n- Security \u0026 auth, 87 against 80\n- Maintenance \u0026 community, 63 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: Audio stops at 2 minutes per request or stream and the cap can't be raised\n\n\n## Why the edge\n\n### Maintenance \u0026 community: Soniox Text-to-Speech +38\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- Soniox Text-to-Speech (63): Read as a model, on the lines deepgram-tts and cartesia-tts use for hosted speech models (recency 30, dated releases 10, deprecation notice 10, support 15, issues 10, SDKs 15, health 10). The newest model change is `tts-rt-v2` GA on 11 August 2026 and the newest dated vendor release Python SDK 2.10.0 on 2 October, 31 days before 2 November (20). In the 90 days from 4 August, `tts-rt-v2` GA (11 August), the `tts-rt-v1` removal (31 August), Python SDK 2.9.0 (11 August) and 2.10.0 (2 October), and the JavaScript SDK tag v2026.08.11 (10 August, counted half) (10; was 0). `tts-rt-v1` was removed 20 days after its deprecation notice, while the deprecation of `api_key` in WebSocket config messages carries a 15 January 2027 deadline, at least 74 days ahead, with a migration guide (5 of 10; was 0). The models page and a support channel, untested (5 of 15). SDK issues couldn't be read because GitHub's pages answered 403 (3 of 10). SDKs for Python, Node, the web and React (15). The Python SDK has a test suite and lock file, but its CI file sits in `.github/` rather than `.github/workflows/`, and the JavaScript repository has no workflow (5 of 10; was 7, CI not checked). 20 + 10 + 5 + 5 + 3 + 15 + 5 = 63.\n\n### Transparency \u0026 trust: Google Cloud Text-to-Speech +14\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- Soniox Text-to-Speech (73): Closed service under terms updated 2026-06-29, Python SDK under Apache-2.0 (15). The security page, the terms and the TTS docs agree on no storage and no training, with async data deleted after 30 days (25 of 30). Model removals are dated on the models page with 20 days' notice for v1, and the WebSocket authentication change is dated to 15 January 2027 with a migration guide, but there is no written policy (12 of 20; was 10). Regional hosts in the US, EU, Japan and India and a data residency page, no sub-processor list found (12 of 20). 15 + 25 + 12 + 12 = 64.\n\n### Agent ergonomics: Soniox Text-to-Speech +13\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- Soniox Text-to-Speech (78): API reading of the checklist. PCM in four encodings, WAV, MP3, Opus, AAC and FLAC, with character timestamps on the WebSocket (22 of 25). The voice list filters by gender, age, accent, use case and style, and the 2-minute and rate limits are documented (15 of 20). Machine-readable `error_type` values an agent can branch on (20). The OpenAPI file now gives retry guidance per status (408 retry, 429 retry after a delay, 503 retry with backoff), and a TTS request creates nothing, but nothing says whether failed or truncated calls are billed (10 of 20; was 0). Model, language, voice, format and text are all set per request. SDKs for Python, Node, the web and React (11 of 15). 22 + 15 + 20 + 10 + 11 = 78.\n\n### Security \u0026 auth: Soniox Text-to-Speech +7\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- Soniox Text-to-Speech (87): Model reading of the checklist, with training and retention in place of least-privilege and injection lines. Project API keys now carry permissions per resource (TTS real-time, cloned voices, usage, model listing, temporary keys, with read and write levels), a missing permission returns 403 `permission_denied`, and an organisation API key can list, create and delete project keys. Temporary keys for browsers expire and are scoped to a `usage_type` (30; was 25). Soniox says audio and text are never used to improve its models (20). Nothing is stored unless you ask, and logs carry no content (15). Per-request usage logs record model, duration, tokens and the client reference id, readable through `GET /v1/usage-logs`, as soniox-stt reads them (10 of 15; was 5). SOC 2 Type 2, ISO/IEC 27001:2022 and HIPAA listed on the security page. The Python SDK's SECURITY.md (since May 2026) gives a disclosure route by email, GitHub, a maintainer or Discord. soniox.com/.well-known/security.txt answers 404 and no bug bounty was found (12 of 20; was 10). 30 + 20 + 15 + 10 + 12 = 87.\n\n### Schema \u0026 documentation: Soniox Text-to-Speech +5\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- Soniox Text-to-Speech (85): Soniox now publishes an OpenAPI 3.1.0 file at docs.soniox.com/openapi.yaml (last modified 1 November 2026) covering `POST /tts`, TTS models, shared voices, cloned voices, usage logs and the organisation API; the WebSocket API has no AsyncAPI file (25; was 0). llms.txt and `.mdx` pages, now on docs.soniox.com (10). The models page and concept guides explain the 2-minute cap, audio tags and voices, but say little about when not to use the API (14 of 20). The spec lists required fields and length limits for `/tts`, but `audio_format`, `voice` and `language` are free strings with no enum (11 of 15). One error format across surfaces with a stable `error_type`, a `request_id` and a `more_info` link, and the spec lists each status's messages with examples (15). Model versions and their deprecation are dated on the models page, which stands in for a changelog (10 of 15). 25 + 10 + 14 + 11 + 15 + 10 = 85.\n\n## Score by category\n\n| Category | Weight | Google Cloud Text-to-Speech | Soniox Text-to-Speech | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 85 | 87 | Soniox Text-to-Speech +2 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 80 | 85 | Soniox Text-to-Speech +5 |\n| Agent ergonomics | 13% (16.2 this run) | 65 | 78 | Soniox Text-to-Speech +13 |\n| Security \u0026 auth | 14% (17.5 this run) | 80 | 87 | Soniox Text-to-Speech +7 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 20 | 20 | even |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 25 | 63 | Soniox Text-to-Speech +38 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 87 | 73 | Google Cloud Text-to-Speech +14 |\n| Negative events | ≤15 | 0 | -3 | |\n| **Total** | | **66.9 · B** | **70.5 · BB** | |\n\n## Facts side by side\n\n| Fact | Google Cloud Text-to-Speech | Soniox Text-to-Speech |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | Google Cloud | Soniox |\n| Hosted endpoint | no (local only) | `https://tts-rt.soniox.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 | $0.0117 per minute of audio |\n| x402 | no | no |\n| Licence | none | Apache-2.0 (Python SDK) |\n| Tools exposed | 0 | none |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2025-12-30 | 2026-10-02 |\n| Terms last updated | 2026-09-02 | 2026-06-29 |\n| Privacy policy last updated | 2026-10-01 | 2026-06-29 |\n| Customer content may train models | yes | not found in the text |\n| Terms restrict automated access | not found in the text | not found in the text |\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 | not found in the text |\n| Popularity | none | 12 stars, 22k npm/wk |\n| Agent reviews | none | 3/5 (2) |\n\n## How the scores have moved\n\n### Google Cloud Text-to-Speech\n\nNo score change since it was listed.\n\n### Soniox Text-to-Speech\n\n- +6.8 on 2 November 2026 (B to BB): product, new evidence, negative event\n- -0.2 on 8 October 2026: checklist\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**Soniox Text-to-Speech.** Content is not stored by default or used for training, keys carry per-resource permissions, an OpenAPI file covers the REST endpoint, and no TTS incident was posted in the 90 days to 2 November. Audio stops at two minutes per request, and Python SDK 2.10.0 removed public interfaces in a minor release without notice.\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### Soniox Text-to-Speech\n\n1. Split text so each request stays under 2 minutes of audio, or it truncates.\n2. Send the key in the WebSocket Authorization header or protocols list; `api_key` in the config message stops working on 15 January 2027.\n3. Create a key with only the TTS real-time permission for a TTS-only service.\n4. Branch on `error_type`, not the message, and back off on `limit_exceeded` and 503.\n5. Pick the regional host (EU, Japan, India) that matches your data residency.\n\n## Questions\n\n### Which is better for AI agents, Google Cloud Text-to-Speech or Soniox Text-to-Speech?\n\nSoniox Text-to-Speech scores 70.5 (BB) on agent readiness against Google Cloud Text-to-Speech's 66.9 (B), and leads in 5 of 7 scored categories. Google Cloud Text-to-Speech leads on transparency \u0026 trust.\n\n### Do Google Cloud Text-to-Speech and Soniox Text-to-Speech need an API key?\n\nGoogle Cloud Text-to-Speech uses an OAuth sign-in. Soniox Text-to-Speech needs an API key.\n\n### Can an agent call Google Cloud Text-to-Speech and Soniox Text-to-Speech without installing anything?\n\nNo hosted endpoint is listed for Google Cloud Text-to-Speech. Soniox Text-to-Speech has a hosted endpoint at https://tts-rt.soniox.com.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/google-cloud-tts-vs-soniox-tts.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"google-cloud-tts\", \"b\": \"soniox-tts\"}`. From a terminal: `anchor compare google-cloud-tts soniox-tts`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/google-cloud-tts.json and https://www.anchorterminal.com/api/v1/tools/soniox-tts.json\n\n## Other comparisons with Google Cloud Text-to-Speech or Soniox Text-to-Speech\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 Soniox Text-to-Speech](https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.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 Soniox Text-to-Speech](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-soniox-tts.md)\n- [Cartesia Sonic TTS API + MCP vs Google Cloud Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-google-cloud-tts.md)\n- [Cartesia Sonic TTS API + MCP vs 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 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 Soniox Text-to-Speech](https://www.anchorterminal.com/compare/deepgram-tts-vs-soniox-tts.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 Soniox Text-to-Speech](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-soniox-tts.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 Soniox Text-to-Speech](https://www.anchorterminal.com/compare/fish-audio-tts-vs-soniox-tts.md)\n- [Google Cloud Text-to-Speech vs HeyGen Voice](https://www.anchorterminal.com/compare/google-cloud-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- [HeyGen Voice vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/heygen-voice-vs-soniox-tts.md)\n- [Inworld Realtime TTS-2 vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/inworld-tts-vs-soniox-tts.md)\n- [MiniMax Speech (T2A) vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/minimax-speech-vs-soniox-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- [Smallest.ai Lightning TTS vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/smallest-lightning-tts-vs-soniox-tts.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "Google Cloud Text-to-Speech vs Soniox Text-to-Speech", "url": "" } ], "description": "Soniox Text-to-Speech scores 70.5 (BB) to Google Cloud Text-to-Speech's 66.9 (B) for text-to-speech. 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