{ "data": { "a": { "slug": "assemblyai-stt", "name": "AssemblyAI Speech-to-Text (Universal)", "vendor": "AssemblyAI", "vendorUrl": "https://www.assemblyai.com", "kind": "model", "category": "speech-to-text", "summary": "Speech-to-text APIs for recorded audio and live streams, with speaker identification, translation and redaction options.", "url": "https://www.anchorterminal.com/tools/assemblyai-stt", "markdownUrl": "https://www.anchorterminal.com/tools/assemblyai-stt.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/assemblyai-stt.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/assemblyai-stt.json", "repo": "https://github.com/AssemblyAI/assemblyai-python-sdk", "license": "MIT (SDKs)", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.assemblyai.com/v2", "packages": [ { "registry": "npm", "name": "assemblyai" }, { "registry": "pypi", "name": "assemblyai" } ], "auth": "api-key", "authNotes": "API key in the `authorization` header. Temporary tokens for browser streaming. The docs MCP needs no key.", "pricing": "usage", "pricingNotes": "Free tier with no card covers up to 185 hours of pre-recorded or 333 hours of streaming. Then pay as you go per hour of audio. Universal-3.5 Pro $0.21, Universal-2 $0.15, Universal-3.6 Pro Realtime $0.45, Universal-Streaming $0.15, Sync $0.45. Diarisation $0.02 an hour on files and $0.12 on streams, keyterms $0.05 on Universal-3.5 Pro, translation $0.06. Streaming bills session time, not audio sent (https://www.assemblyai.com/pricing).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing. Card or prepaid credits only (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 213, "npmWeekly": 599958, "pypiWeekly": 738086, "asOf": "2026-09-30" }, "docsUrl": "https://www.assemblyai.com/docs", "llmsTxt": "https://www.assemblyai.com/docs/llms.txt", "openapi": "https://www.assemblyai.com/docs/openapi.yaml", "capabilities": [ "speech.stt", "speech.streaming", "speech.batch", "speech.diarisation", "speech.languages", "speech.translation" ], "tags": [ "hosted", "no-card", "free-tier", "closed-source", "python", "typescript", "openapi", "llms-txt", "mcp", "streaming", "batch", "webhooks", "async-jobs", "enterprise" ], "lastRelease": "2026-09-24", "graded": true, "anchor": { "graded": true, "score": 67, "grade": "B", "agentReady": false, "rank": 148, "ranked": true, "rankOf": 452, "categoryRank": 8, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 80, "maintenance": 80, "payments": 40, "reliability": 70, "schema": 95, "security": 50, "transparency": 78 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": -3, "negativeNotes": [ "2026-07-10, the async `speech_model` parameter began returning 400 for current model names and silently routing legacy names to the default model, and `universal-3-pro` was blocked for new accounts and accounts inactive for 7 days, all announced in the changelog the same day. We found no earlier notice (https://www.assemblyai.com/changelog). Documented, so the minimum deduction." ], "verdict": "OpenAPI 3.1 file with typed inputs and error responses on every operation. Two outages of an hour or more in the last 90 days, on 31 July and 16 September 2026.", "strengths": [ "OpenAPI 3.1 file with typed inputs and error responses on every operation", "Universal-2 covers 99 languages at $0.15 an hour, Universal-3.5 Pro is $0.21", "Transcript lists paginate with `limit`, `before_id` and `after_id`, and transcripts come back as sentences, paragraphs, SRT or VTT", "Free tier with no card, up to 185 hours pre-recorded", "TTL deletion from 1 hour and a delete endpoint for transcripts" ], "weaknesses": [ "Two outages of an hour or more in the last 90 days, on 31 July and 16 September 2026", "Free accounts can't opt out of model training", "The HTTP rate limit returns 403 with no Retry-After", "Streaming bills the time the socket is open, up to a 3-hour auto-close", "No security.txt or published disclosure policy" ], "agentNotes": [ "Send `{\"type\":\"Terminate\"}` to close every stream, or billing runs to the 3-hour auto-close", "Use `speech_models` (plural). The singular `speech_model` now returns 400 for current model names", "Treat a 403 on polling as the rate limit and back off with jitter, or use webhooks", "Fetch `/sentences` or `/paragraphs` instead of the full transcript when you only need text", "Opt out in Data Controls on a paid account before sending customer audio" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 67 } ], "editorialScores": { "ergonomics": 80, "maintenance": 80, "payments": 40, "reliability": 70, "schema": 95, "security": 50, "transparency": 70 }, "provenanceScore": 86 }, "connect": { "http": "curl -X POST https://api.assemblyai.com/v2/transcript -H \"authorization: $ASSEMBLYAI_API_KEY\" \\\n -H \"content-type: application/json\" \\\n -d '{\"audio_url\":\"https://assembly.ai/wildfires.mp3\",\"language_detection\":true,\"speaker_labels\":true}'", "claudeCode": "claude mcp add assemblyai-docs --transport http https://assemblyai.com/docs/mcp" }, "letme": { "capability": "https://letme.dev/speech.stt", "tool": "https://letme.dev/assemblyai-stt" }, "area": "voice", "unitPrices": [ { "item": "Universal-3.5 Pro pre-recorded", "unit": "audio-minute", "usd": 0.0035, "note": "published as $0.21 an hour" }, { "item": "Universal-2 pre-recorded", "unit": "audio-minute", "usd": 0.0025, "note": "published as $0.15 an hour" }, { "item": "Universal-3.6 Pro Realtime", "unit": "audio-minute", "usd": 0.0075, "note": "published as $0.45 an hour, billed on session time" }, { "item": "Universal-Streaming", "unit": "audio-minute", "usd": 0.0025, "note": "published as $0.15 an hour, billed on session time" }, { "item": "Sync API", "unit": "audio-minute", "usd": 0.0075, "note": "published as $0.45 an hour, clips up to 2 minutes" }, { "item": "Streaming diarisation add-on", "unit": "audio-minute", "usd": 0.002, "note": "published as $0.12 an hour" } ], "provenance": { "legalEntity": "AssemblyAI, Inc.", "domain": "assemblyai.com", "domainRegistered": "2016-12-24", "endpointOnVendorDomain": true, "terms": "https://www.assemblyai.com/legal/terms-of-service", "privacy": "https://www.assemblyai.com/legal/privacy-policy", "statusPage": "https://status.assemblyai.com", "changelog": "https://www.assemblyai.com/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 86 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/assemblyai-stt.json", "live": { "slug": "assemblyai-stt", "probe": { "target": "https://api.assemblyai.com/v2", "method": "get", "lastAt": "2026-10-04T23:32:43.1361406Z", "lastOk": true, "lastStatus": 404, "lastMs": 444, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 443, "p95ms24h": 487, "samples24h": 272, "samples30d": 1097, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 267, "ok": 267 } ] }, "vendorStatus": { "page": "https://status.assemblyai.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-04T23:27:39.943165483Z" }, "versions": [ { "registry": "github", "name": "AssemblyAI/assemblyai-python-sdk", "version": "1.6.1", "released": "2026-09-24", "seenAt": "2026-10-04T16:20:56.490457181Z" }, { "registry": "npm", "name": "assemblyai", "version": "4.41.5", "seenAt": "2026-10-04T16:20:55.58059221Z" }, { "registry": "pypi", "name": "assemblyai", "version": "1.6.1", "released": "2026-09-24", "seenAt": "2026-10-04T16:20:56.382722009Z" } ], "githubStars": 213, "npmWeekly": 645780, "pypiWeekly": 817313, "securityTxt": { "url": "https://assemblyai.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:16:02.784112938Z" }, "llmsTxt": { "url": "https://www.assemblyai.com/docs/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:15.941338129Z" }, "domain": { "domain": "assemblyai.com", "registered": "2016-12-24", "source": "https://rdap.verisign.com/com/v1/domain/assemblyai.com", "checkedAt": "2026-10-04T13:07:48.940216522Z" }, "pages": [ { "url": "https://www.assemblyai.com/changelog", "kind": "changelog", "status": 304, "checkedAt": "2026-10-04T15:49:11.730936349Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "f7dbbe98a56a" }, { "url": "https://www.assemblyai.com/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:49:17.853952095Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "07bb01ccd4d1" }, { "url": "https://www.assemblyai.com/legal/privacy-policy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:49:13.761556773Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "6671be50624e" }, { "url": "https://www.assemblyai.com/legal/terms-of-service", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:49:15.761345368Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "766c6ee47ebc" } ], "updatedAt": "2026-10-04T23:32:43.1361406Z" } }, "b": { "slug": "deepgram-stt", "name": "Deepgram Speech-to-Text (Nova-3, Flux)", "vendor": "Deepgram", "vendorUrl": "https://deepgram.com", "kind": "model", "category": "speech-to-text", "summary": "Deepgram's speech-to-text API for recorded audio and live streams, including turn detection for voice agents.", "url": "https://www.anchorterminal.com/tools/deepgram-stt", "markdownUrl": "https://www.anchorterminal.com/tools/deepgram-stt.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/deepgram-stt.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/deepgram-stt.json", "repo": "https://github.com/deepgram/deepgram-python-sdk", "license": "MIT (SDKs)", "transports": [ "http", "streamable-http", "stdio", "sse" ], "remoteUrl": "https://api.deepgram.com/v1", "packages": [ { "registry": "npm", "name": "@deepgram/sdk" }, { "registry": "pypi", "name": "deepgram-sdk" }, { "registry": "pypi", "name": "deepctl" } ], "auth": "api-key", "authNotes": "`Authorization: Token \u003ckey\u003e` header on REST and WebSocket calls. Short-lived JWTs (30-second TTL) from the token endpoint for browsers. The `dg` CLI MCP server uses `dg login` credentials or `DEEPGRAM_API_KEY`. The docs MCP needs no key.", "pricing": "usage", "pricingNotes": "$200 free credit with no card, then pay as you go, or Growth from $4,000 a year prepaid for up to 20 per cent off. Nova-3 pre-recorded $0.0043 a minute (multilingual $0.0052). Streaming Nova-3 is on a promotional $0.0048 a minute (regular $0.0077), multilingual $0.0058 (regular $0.0092). Flux English $0.0065 promotional (regular $0.0077), Flux Multilingual $0.0078. Streaming diarisation adds $0.0020 a minute, redaction $0.0020 and keyterm prompting $0.0013 (https://deepgram.com/pricing).", "priceSummary": "Pay per use", "where": "both", "x402": { "level": "no", "evidence": "No x402 or machine payment in the docs or pricing. Card or prepaid credits only (checked 2026-09-30).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 468, "npmWeekly": 1123798, "pypiWeekly": 805026, "asOf": "2026-09-30" }, "docsUrl": "https://developers.deepgram.com/docs/models-languages-overview", "llmsTxt": "https://developers.deepgram.com/llms.txt", "openapi": "https://developers.deepgram.com/openapi.json", "capabilities": [ "speech.stt", "speech.streaming", "speech.batch", "speech.diarisation", "speech.languages" ], "tags": [ "hosted", "no-card", "closed-source", "python", "typescript", "openapi", "llms-txt", "mcp", "streaming", "batch", "webhooks", "enterprise", "self-hosted" ], "lastRelease": "2026-09-29", "graded": true, "anchor": { "graded": true, "score": 70.6, "grade": "BB", "agentReady": true, "rank": 94, "ranked": true, "rankOf": 452, "categoryRank": 3, "methodology": "0.3", "run": "2026-10-01", "scores": { "ergonomics": 75, "maintenance": 80, "payments": 40, "reliability": 65, "schema": 95, "security": 65, "transparency": 75 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-01" }, "negative": 0, "verdict": "Flux streams with model-level end-of-turn detection, so a voice agent needs no separate VAD. Training on audio is the default and the opt-out is a per-request flag.", "strengths": [ "Flux streams with model-level end-of-turn detection, so a voice agent needs no separate VAD", "Nova-3 pre-recorded at $0.0043 a minute with diarisation included", "OpenAPI and AsyncAPI files, an llms.txt and SDKs in six languages", "Keys can carry a role and an expiry date", "$200 free credit with no card" ], "weaknesses": [ "Training on audio is the default and the opt-out is a per-request flag", "Two incidents over 2 hours in July 2026, on Flux streaming and batch", "No SLA published for self-serve plans", "The privacy policy dates from October 2021 and doesn't mention the Model Improvement Program", "Streaming prices are promotional and may rise to the regular rate" ], "agentNotes": [ "Add `mip_opt_out=true` to every request that carries customer audio", "Use Flux (`flux-general-en`) on `/v2/listen` for live agents and Nova-3 for files", "Back off exponentially on 429. The concurrency limit is per project", "Pass `callback` for long files so the request doesn't hit the 10-minute processing timeout", "Mint keys with an expiry for short-lived jobs" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 2, "avgRating": 3.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.3", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 70.6 } ], "editorialScores": { "ergonomics": 75, "maintenance": 80, "payments": 40, "reliability": 65, "schema": 95, "security": 65, "transparency": 60 }, "provenanceScore": 90 }, "connect": { "http": "curl -X POST \"https://api.deepgram.com/v1/listen?model=nova-3\u0026smart_format=true\u0026diarize=true\" \\\n -H \"Authorization: Token $DEEPGRAM_API_KEY\" -H \"content-type: application/json\" \\\n -d '{\"url\":\"https://dpgr.am/spacewalk.wav\"}'", "claudeCode": "claude mcp add deepgram-docs --transport http https://api.dx.deepgram.com/kapa/mcp", "config": { "mcpServers": { "deepgram": { "args": [ "mcp" ], "command": "dg", "env": { "DEEPGRAM_API_KEY": "${DEEPGRAM_API_KEY}" } } } } }, "letme": { "capability": "https://letme.dev/speech.stt", "tool": "https://letme.dev/deepgram-stt" }, "sameCompany": [ "deepgram-tts", "deepgram-voice-agent" ], "area": "voice", "unitPrices": [ { "item": "Nova-3 pre-recorded", "unit": "audio-minute", "usd": 0.0043, "note": "pay as you go, diarisation included" }, { "item": "Nova-3 Multilingual pre-recorded", "unit": "audio-minute", "usd": 0.0052 }, { "item": "Nova-3 streaming", "unit": "audio-minute", "usd": 0.0048, "note": "promotional, regular $0.0077" }, { "item": "Nova-3 Multilingual streaming", "unit": "audio-minute", "usd": 0.0058, "note": "promotional, regular $0.0092" }, { "item": "Flux English streaming", "unit": "audio-minute", "usd": 0.0065, "note": "promotional, regular $0.0077" }, { "item": "Flux Multilingual streaming", "unit": "audio-minute", "usd": 0.0078 }, { "item": "Streaming diarisation add-on", "unit": "audio-minute", "usd": 0.002 } ], "provenance": { "legalEntity": "Deepgram, Inc.", "domain": "deepgram.com", "domainRegistered": "2016-01-28", "endpointOnVendorDomain": true, "terms": "https://deepgram.com/terms", "privacy": "https://deepgram.com/privacy", "statusPage": "https://status.deepgram.com", "changelog": "https://developers.deepgram.com/changelog", "securityTxt": "none", "checked": "2026-09-30", "score": 90 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/deepgram-stt.json", "live": { "slug": "deepgram-stt", "probe": { "target": "https://api.deepgram.com/v1", "method": "get", "lastAt": "2026-10-04T23:32:46.256106233Z", "lastOk": true, "lastStatus": 404, "lastMs": 325, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 409, "p95ms24h": 574, "samples24h": 272, "samples30d": 1097, "days": [ { "date": "2026-09-30", "probes": 35, "ok": 35 }, { "date": "2026-10-01", "probes": 276, "ok": 276 }, { "date": "2026-10-02", "probes": 248, "ok": 248 }, { "date": "2026-10-03", "probes": 271, "ok": 271 }, { "date": "2026-10-04", "probes": 267, "ok": 267 } ] }, "vendorStatus": { "page": "https://status.deepgram.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-10-04T23:27:44.328583959Z" }, "versions": [ { "registry": "github", "name": "deepgram/deepgram-python-sdk", "version": "v7.12.0", "released": "2026-10-02", "seenAt": "2026-10-04T16:25:14.377162819Z" }, { "registry": "npm", "name": "@deepgram/sdk", "version": "5.14.0", "seenAt": "2026-10-04T16:25:11.388177933Z" }, { "registry": "pypi", "name": "deepctl", "version": "0.3.1", "released": "2026-09-29", "seenAt": "2026-10-04T16:25:12.495057478Z" }, { "registry": "pypi", "name": "deepgram-sdk", "version": "7.12.0", "released": "2026-10-02", "seenAt": "2026-10-04T16:25:12.291142743Z" } ], "githubStars": 468, "npmWeekly": 1147181, "pypiWeekly": 806541, "securityTxt": { "url": "https://deepgram.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-04T15:16:00.338324598Z" }, "llmsTxt": { "url": "https://developers.deepgram.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-10-04T15:17:29.891823062Z" }, "domain": { "domain": "deepgram.com", "registered": "2016-01-28", "source": "https://rdap.verisign.com/com/v1/domain/deepgram.com", "checkedAt": "2026-10-04T13:03:28.939824686Z" }, "pages": [ { "url": "https://developers.deepgram.com/changelog", "kind": "changelog", "status": 304, "checkedAt": "2026-10-04T15:42:47.246047138Z", "changedAt": "2026-10-03T15:30:58.169955011Z", "fingerprint": "906a55c83273" }, { "url": "https://deepgram.com/pricing", "kind": "pricing", "status": 304, "checkedAt": "2026-10-04T15:42:22.716687514Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "9dc1aeac38eb" }, { "url": "https://deepgram.com/privacy", "kind": "privacy", "status": 304, "checkedAt": "2026-10-04T15:42:24.872646912Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "89846510fbe6" }, { "url": "https://deepgram.com/terms", "kind": "terms", "status": 304, "checkedAt": "2026-10-04T15:42:26.768797703Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "7042d107fca1" } ], "updatedAt": "2026-10-04T23:32:46.256106233Z" } }, "summary": "Deepgram Speech-to-Text (Nova-3, Flux) has a score of 70.6 (BB) against AssemblyAI Speech-to-Text (Universal)'s 67 (B). Both do speech stt. The largest gap is security \u0026 auth, 15 points." }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/assemblyai-stt-vs-deepgram-stt", "json": "https://www.anchorterminal.com/compare/assemblyai-stt-vs-deepgram-stt.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/assemblyai-stt-vs-deepgram-stt.md", "slim": "https://www.anchorterminal.com/compare/assemblyai-stt-vs-deepgram-stt.min.md" }, "markdown": "Deepgram Speech-to-Text (Nova-3, Flux) has a score of 70.6 (BB) against AssemblyAI Speech-to-Text (Universal)'s 67 (B). Both do speech stt. The largest gap is security \u0026 auth, 15 points.\n\n- AssemblyAI Speech-to-Text (Universal): grade B, 67/100, rank #148 of 452. Markdown https://www.anchorterminal.com/tools/assemblyai-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/assemblyai-stt.json\n- Deepgram Speech-to-Text (Nova-3, Flux): grade BB, 70.6/100, rank #94 of 452. Markdown https://www.anchorterminal.com/tools/deepgram-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/deepgram-stt.json\n\n## Which one, for what\n\nPick AssemblyAI Speech-to-Text (Universal) for reliability (+5), agent ergonomics (+5).\n\nPick Deepgram Speech-to-Text (Nova-3, Flux) for security \u0026 auth (+15).\n\n## Score by category\n\n| Category | Weight | AssemblyAI Speech-to-Text (Universal) | Deepgram Speech-to-Text (Nova-3, Flux) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 70 | 65 | AssemblyAI Speech-to-Text (Universal) +5 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 95 | 95 | even |\n| Agent ergonomics | 13% (16.2 this run) | 80 | 75 | AssemblyAI Speech-to-Text (Universal) +5 |\n| Security \u0026 auth | 14% (17.5 this run) | 50 | 65 | Deepgram Speech-to-Text (Nova-3, Flux) +15 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 40 | even |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 80 | 80 | even |\n| Transparency \u0026 trust | 7% (8.8 this run) | 78 | 75 | AssemblyAI Speech-to-Text (Universal) +3 |\n| Negative events | ≤15 | -3 | 0 | |\n| **Total** | | **67 · B** | **70.6 · BB** | |\n\n## Facts side by side\n\n| Fact | AssemblyAI Speech-to-Text (Universal) | Deepgram Speech-to-Text (Nova-3, Flux) |\n| --- | --- | --- |\n| Kind | Model API | Model API |\n| Vendor | AssemblyAI | Deepgram |\n| Hosted endpoint | `https://api.assemblyai.com/v2` | `https://api.deepgram.com/v1` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP, stdio, SSE (legacy) |\n| Auth | API key | API key |\n| Pricing | Pay per use | Pay per use |\n| x402 | no | no |\n| Licence | MIT (SDKs) | MIT (SDKs) |\n| Tools exposed | none | none |\n| Context cost (tools/list) | n/a | n/a |\n| p95 latency | not measured yet | not measured yet |\n| Availability (30d) | not measured yet | not measured yet |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| MCP registry | not listed | not listed |\n| Last release | 2026-09-24 | 2026-09-29 |\n| Popularity | 213 stars, 600k npm/wk, 738k PyPI/wk | 468 stars, 1.1M npm/wk, 805k PyPI/wk |\n| Agent reviews | 3.5/5 (2) | 3.5/5 (2) |\n\n## Verdicts\n\n**AssemblyAI Speech-to-Text (Universal).** OpenAPI 3.1 file with typed inputs and error responses on every operation. Two outages of an hour or more in the last 90 days, on 31 July and 16 September 2026.\n\n**Deepgram Speech-to-Text (Nova-3, Flux).** Flux streams with model-level end-of-turn detection, so a voice agent needs no separate VAD. Training on audio is the default and the opt-out is a per-request flag.\n\n## Before you call either\n\n### AssemblyAI Speech-to-Text (Universal)\n\n1. Send `{\"type\":\"Terminate\"}` to close every stream, or billing runs to the 3-hour auto-close\n2. Use `speech_models` (plural). The singular `speech_model` now returns 400 for current model names\n3. Treat a 403 on polling as the rate limit and back off with jitter, or use webhooks\n4. Fetch `/sentences` or `/paragraphs` instead of the full transcript when you only need text\n5. Opt out in Data Controls on a paid account before sending customer audio\n\n### Deepgram Speech-to-Text (Nova-3, Flux)\n\n1. Add `mip_opt_out=true` to every request that carries customer audio\n2. Use Flux (`flux-general-en`) on `/v2/listen` for live agents and Nova-3 for files\n3. Back off exponentially on 429. The concurrency limit is per project\n4. Pass `callback` for long files so the request doesn't hit the 10-minute processing timeout\n5. Mint keys with an expiry for short-lived jobs\n\n## Other comparisons with AssemblyAI Speech-to-Text (Universal) or Deepgram Speech-to-Text (Nova-3, Flux)\n\n- [Amazon Transcribe vs AssemblyAI Speech-to-Text (Universal)](https://www.anchorterminal.com/compare/amazon-transcribe-vs-assemblyai-stt.md)\n- [Amazon Transcribe vs Deepgram Speech-to-Text (Nova-3, Flux)](https://www.anchorterminal.com/compare/amazon-transcribe-vs-deepgram-stt.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Azure AI Speech speech-to-text](https://www.anchorterminal.com/compare/assemblyai-stt-vs-azure-speech-to-text.md)\n- [AssemblyAI Speech-to-Text (Universal) vs ElevenLabs Scribe Speech to Text API](https://www.anchorterminal.com/compare/assemblyai-stt-vs-elevenlabs-scribe.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Gladia Speech-to-Text API + MCP](https://www.anchorterminal.com/compare/assemblyai-stt-vs-gladia-stt.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Google Cloud Speech-to-Text](https://www.anchorterminal.com/compare/assemblyai-stt-vs-google-speech-to-text.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Rev AI Speech-to-Text API](https://www.anchorterminal.com/compare/assemblyai-stt-vs-rev-ai-stt.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Soniox Speech-to-Text](https://www.anchorterminal.com/compare/assemblyai-stt-vs-soniox-stt.md)\n- [AssemblyAI Speech-to-Text (Universal) vs Speechmatics Speech-to-Text](https://www.anchorterminal.com/compare/assemblyai-stt-vs-speechmatics-stt.md)\n- [Azure AI Speech speech-to-text vs Deepgram Speech-to-Text (Nova-3, Flux)](https://www.anchorterminal.com/compare/azure-speech-to-text-vs-deepgram-stt.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs ElevenLabs Scribe Speech to Text API](https://www.anchorterminal.com/compare/deepgram-stt-vs-elevenlabs-scribe.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs Gladia Speech-to-Text API + MCP](https://www.anchorterminal.com/compare/deepgram-stt-vs-gladia-stt.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs Google Cloud Speech-to-Text](https://www.anchorterminal.com/compare/deepgram-stt-vs-google-speech-to-text.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs Rev AI Speech-to-Text API](https://www.anchorterminal.com/compare/deepgram-stt-vs-rev-ai-stt.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs Soniox Speech-to-Text](https://www.anchorterminal.com/compare/deepgram-stt-vs-soniox-stt.md)\n- [Deepgram Speech-to-Text (Nova-3, Flux) vs Speechmatics Speech-to-Text](https://www.anchorterminal.com/compare/deepgram-stt-vs-speechmatics-stt.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-04", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.3", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "AssemblyAI Speech-to-Text (Universal) vs Deepgram Speech-to-Text (Nova-3, Flux)", "url": "" } ], "description": "Deepgram Speech-to-Text (Nova-3, Flux) has a score of 70.6 (BB) against AssemblyAI Speech-to-Text (Universal)'s 67 (B). Both do speech stt. The largest gap is security \u0026 auth, 15 points. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "AssemblyAI Speech-to-Text (Universal) B 67", "Deepgram Speech-to-Text (Nova-3, Flux) BB 70.6", "scores" ], "h1": "AssemblyAI Speech-to-Text (Universal) vs Deepgram Speech-to-Text (Nova-3, Flux)", "image": "https://www.anchorterminal.com/assets/og/compare-assemblyai-stt-vs-deepgram-stt.png", "path": "/compare/assemblyai-stt-vs-deepgram-stt", "published": "2026-10-01", "section": "tools", "title": "AssemblyAI Speech-to-Text (Universal) vs Deepgram Speech-to-Text…", "toc": null, "updated": "2026-10-04", "url": "https://www.anchorterminal.com/compare/assemblyai-stt-vs-deepgram-stt" }, "tokens": { "markdown": 1850, "slim": 380 }, "version": 1 }