AssemblyAI

Best for: Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt); Teams needing broad API coverage out of the box

Avoid if: You want to try it free before paying

Pricing model

Usage-based [2]assemblyai.com/pricing“Universal-3 Pro: $0.21/hr; Universal-2: $0.15/hr — per audio hour with no mandatory recurring base fee”

Published pricing

✓ Yes [3]assemblyai.com/pricing“Universal-3 Pro: $0.21/hr | Universal-2: $0.15/hr | Speaker Diarization: +$0.02–$0.12/hr | Medical Mode: +$0.15/hr”

Free tier

✗ No [4]assemblyai.com/pricing“$50 in free credits, no credit card required — one-time signup credit, not a recurring monthly allowance”

Free tier details

$50 one-time credit on signup, no credit card required (not a recurring free tier)

Self-serve signup

✓ Yes [5]assemblyai.com/pricing“$50 in free credits, no credit card required.”

Requires sales call

✗ No

Enterprise plan

✓ Yes [6]assemblyai.com/pricing“enterprise contracts for higher concurrency limits”

• Real-time streaming
• Speaker diarization
• Speech translation
• Medical transcription
• PII redaction

Supported actions

transcribe_batch, transcribe_streaming, speaker_diarization, language_detection, word_timestamps, sentiment_analysis, entity_detection, topic_detection, pii_redaction, pii_audio_redaction, profanity_filtering, content_moderation, multichannel_transcription, custom_vocabulary, keyterms_prompting, webhook_notifications, medical_mode, automatic_punctuation, code_switching_detection, translation, voice_focus_noise_reduction, general_prompting [7]assemblyai.com/docs/api-reference/transcripts/submit“Diarization: Speaker labeling with configurable speaker count | Language Detection: Auto-detection with confidence thresholds | Sentiment Analysis: Per-utterance emotional tone classification | Entity Detection: Identifies locations, person names, organizations | Topic Detection: IAB category classification | Word Timestamps: Granular timing for each word with confidence scores | PII Redaction: Text and audio redaction”

Regions

United States, European Union (Dublin, Ireland) [8]assemblyai.com/security“Data processing occurs in Dublin, Ireland, allowing customers to store and process data within the United States or European Union.”

Languages

English, Spanish, French, German, Indonesian, Italian, Japanese, Dutch, Polish, Portuguese, Russian, Swedish, Turkish, Ukrainian, Catalan, Arabic, Azerbaijani, Bulgarian, Bosnian, Mandarin Chinese, Czech, Danish, Greek, Estonian, Finnish, Galician, Hebrew, Hindi, Croatian, Hungarian, Korean, Macedonian, Malay, Norwegian, Romanian, Slovak, Swiss German, Tagalog, Thai, Urdu, Vietnamese, Afrikaans, Belarusian, Welsh, Persian, Armenian, Icelandic, Kazakh, Lithuanian, Latvian, Maori, Marathi, Slovenian, Swahili, Tamil, Amharic, Assamese, Bengali, Gujarati, Hausa, Javanese, Georgian, Khmer, Kannada, Luxembourgish, Lingala, Lao, Malayalam, Mongolian, Maltese, Burmese, Nepali, Occitan, Punjabi, Pashto, Sindhi, Shona, Somali, Serbian, Telugu, Tajik, Uzbek, Yoruba [9]assemblyai.com/docs/speech-to-text/supported-languages“High Accuracy (≤10% WER): English, Spanish, French, German, Indonesian, Italian, Japanese, Dutch, Polish, Portuguese, Russian, Swedish, Turkish, Ukrainian, Catalan”assemblyai.com/docs/getting-started/supported-languages“AssemblyAI supports 99+ languages across their speech-to-text models, organized by accuracy tiers”

Input types

audio/mpeg (MP3), audio/wav (WAV), audio/aac (AAC), audio/flac (FLAC), audio/ogg (OGG, OGA, MOGG), audio/opus (OPUS), audio/aiff (AIF, AIFF), audio/alac (ALAC), audio/amr (AMR), audio/mp4 (M4A, M4B, M4P, M4R), audio/ac3 (AC3), audio/ape (APE), audio/dss (DSS), audio/flv (FLV), audio/wma (WMA), audio/wv (WV), audio/qcp (QCP), audio/tta (TTA), audio/voc (VOC), video/mp4 (MP4, M4V), video/webm (WEBM), video/quicktime (MOV), video/ts (TS, MTS, M2TS), video/mp2 (MP2), video/mxf (MXF), file URL, local file upload, WebSocket (streaming), live audio stream [10]support.assemblyai.com/articles/2616970375-what-audio-and-video-file-types-are-supported-by-your-api“.3ga, .8svx, .aac, .ac3, .aif, .aiff, .alac, .amr, .ape, .au, .dss, .flac, .flv, .m4a, .m4b, .m4p, .m4r, .mp3, .mpga, .ogg, .oga, .mogg, .opus, .qcp, .tta, .voc, .wav, .wma, and .wv”

Output types

JSON transcript with word-level timestamps, confidence scores, speaker-labeled utterances, sentiment analysis results, entity detection results, topic/IAB category results, SRT captions, VTT captions, redacted audio (beep or silence)

Webhooks

✓ Yes [11]assemblyai.com/docs/getting-started/webhooks“when the transcript is ready, AssemblyAI will send a POST HTTP request to the URL that you specified”

Sandbox / test mode

✗ No [12]assemblyai.com/pricing“$50 in free credits, no credit card required — trial credits used in the live production environment, no separate sandbox environment”

SDK languages

Python, Node.js, C#/.NET, Java [13]github.com/AssemblyAI/assemblyai-java-sdk“As of April 2025, AssemblyAI Java SDK has been discontinued and will no longer be maintained”assemblyai.com/docs/getting-started“Python 3.8+ required; install via pip install assemblyai — JavaScript Node.js 18+ required; install via npm install assemblyai”github.com/AssemblyAI/assemblyai-go-sdk“As of April 2025, AssemblyAI Go SDK has been discontinued and will no longer be maintained. The repository was archived on April 1, 2025 and is now read-only.”

MCP server

✓ Yes [14]assemblyai.com/blog/assemblyai-april-2026-recap“AssemblyAI released a Model Context Protocol server that lets AI tools like Claude Code and other MCP-compatible agents interact directly with the AssemblyAI API.”assemblyai.com/docs/getting-started“claude mcp add --transport http --scope user assemblyai-docs https://assemblyai.com/docs/mcp”

SOC 2

SOC 2 Type II [15]assemblyai.com/security“SOC 2 Type 2 certification verifies that AssemblyAI has successfully completed a thorough audit, certifying that our security policies and controls continuously meet the highest industry standards.”

HIPAA

✓ Yes [16]assemblyai.com/docs/faq/can-you-sign-a-baa“AssemblyAI is considered a business associate under HIPAA, and we offer a standard Business Associate Addendum (BAA).”

GDPR

✓ Yes [17]assemblyai.com/security“Completed third-party assessment with compliance report documenting security control testing”assemblyai.com/docs/faq/can-i-sign-a-dpa-agreement-with-assemblyai“you automatically agree to a Data Processing Addendum (DPA) as part of our terms of service”

ISO 27001

✓ Yes [18]assemblyai.com/blog/expanding-enterprise-security-and-data-residency-capabilities“successfully achieved ISO 27001 certification, which validates their Information Security Management System (ISMS) covering infrastructure, processes, technology, and personnel.”

PCI DSS

✓ Yes [19]assemblyai.com/security“AssemblyAI is PCI-DSS 4.0 Level 1 compliant as of March 31, 2025, upgraded from version 3.2.1.”

Published SLA

✓ Yes [20]assemblyai.com/security“AssemblyAI provides all contracted customers with 99.9% uptime.”

Rate limits

Free tier: 5 new streams per minute (streaming); Pay-as-you-go: 100 new streams per minute. Max file size for /v2/transcript: 5GB; max audio duration: 10 hours. Max local file upload via /v2/upload: 2.2GB. General API rate limit: 20,000 requests per 5 minutes. [21]assemblyai.com/pricing“Free tier: 5 new streams per minute; Pay-as-you-go: 100 new streams per minute”assemblyai.com/docs/faq/are-there-any-limits-on-file-size-or-file-duration-for-files-submitted-to-the-api“maximum file size that can be submitted to the /v2/transcript endpoint for transcription is 5GB; maximum duration is 10 hours”

Known restrictions

Maximum file size for transcription endpoint: 5GB, Maximum audio duration: 10 hours, Maximum local file upload size: 2.2GB, Free-tier streaming concurrency: 5 new streams/minute, Pay-as-you-go streaming concurrency: 100 new streams/minute, Java, C#/.NET, Go, and Ruby SDKs discontinued April 2025; only Python and JavaScript SDKs are actively maintained, Summarization and Auto Chapters features deprecated (migrate to LLM Gateway)

• Docs
• API reference
• OpenAPI spec
• llms.txt
• Changelog
• Status page

Docs rendering: static · llms.txt present

API style

rest

Base URL

https://api.assemblyai.com

Version

v2

Versioning

url

Stability

ga

Auth methods

api_key

Idempotency keys

✗ No

Error format

vendor-specific

Rate limit

20000 / 5 minutes

SDKs

• Python assemblyai · repo
• Node.js assemblyai · repo
• C#/.NET AssemblyAI · repo
• Java com.assemblyai:assemblyai-java · repo

• Auth docs
• Quickstart
• MCP server
• Webhook events
• Deprecation policy

Launched

2017-01-01

Notable customers

Zoom, Spotify, Veed, CallRail, Dovetail, Calabrio, Kapwing, Jiminny, Grain, Supernormal

• ElevenLabs Scribe (Speech to Text)

  "Scribe v2 is the most accurate Speech to Text model" offering "real-time Speech to Text in under 150 ms" across "90+ languages."

  Hybrid · free tier · public pricing · self-serve

• Azure AI Speech to Text

  "Azure Speech in Foundry Tools provides speech to text, text to speech, and other capabilities through a Microsoft Foundry resource. You can transcribe speech to text with high accuracy, produce natural-sounding text-to-speech voices, translate spoken audio, and conduct live AI voice conversations."

  Usage · free tier · public pricing · self-serve

• Amazon Transcribe

  "Amazon Transcribe is an automatic speech recognition service that uses machine learning models to convert audio to text. You can use Amazon Transcribe as a standalone transcription service or to add speech-to-text capabilities to any application."

  Usage · free tier · public pricing · self-serve

• Google Cloud Speech-to-Text

  "Accurate voice typing and transcription powered by Gemini."

  Usage · free tier · public pricing · self-serve

• IBM watsonx Speech to Text

  "IBM Watson® Speech to Text technology enables fast and accurate speech transcription in multiple languages for a variety of use cases, including but not limited to customer self-service, agent assistance and speech analytics."

  Usage · free tier · public pricing · self-serve

• Speechmatics

  "Low-latency speech-to-text for multilingual, multi-speaker conversations."

  Usage · free tier · public pricing · self-serve

AssemblyAI alternatives · AssemblyAI vs ElevenLabs Scribe (Speech to Text) · All Speech-to-Text & Transcription APIs APIs

Each field above carries a numbered source - hover for a preview, click to jump here.

1. ↑Description: assemblyai.com
2. ↑Pricing model: assemblyai.com
3. ↑Published pricing: assemblyai.com
4. ↑Free tier: assemblyai.com
5. ↑Self-serve signup: assemblyai.com
6. ↑Enterprise plan: assemblyai.com
7. ↑Supported actions: assemblyai.com
8. ↑Regions: assemblyai.com
9. ↑Languages: assemblyai.com · assemblyai.com
10. ↑Input types: support.assemblyai.com
11. ↑Webhooks: assemblyai.com
12. ↑Sandbox: assemblyai.com
13. ↑SDK languages: github.com · assemblyai.com · github.com
14. ↑MCP server: assemblyai.com · assemblyai.com
15. ↑SOC 2: assemblyai.com
16. ↑HIPAA: assemblyai.com
17. ↑GDPR: assemblyai.com · assemblyai.com
18. ↑ISO 27001: assemblyai.com
19. ↑PCI DSS: assemblyai.com
20. ↑Published SLA: assemblyai.com
21. ↑Rate limits: assemblyai.com · assemblyai.com

Every field change, who made it, and when - from our audited data pipeline and editors.

1. 2026-06-21 Capabilities: {} → {"medical":true,"translation":true,"pii_redaction":true,"real_time_streaming":t…
2. 2026-06-21 Summary Md: (none) → AssemblyAI is a voice AI platform providing speech-to-text transcription, speak…
3. 2026-06-21 Score Pricing Transparency: (none) → 85
4. 2026-06-21 Score Setup Speed: (none) → 60
5. 2026-06-21 Score Docs Quality: (none) → 75
6. 2026-06-21 Score Procurement Friction: (none) → 85
7. 2026-06-21 Score Trust Readiness: (none) → 100
8. 2026-06-21 Best For: (none) → Regulated or enterprise workloads - compliance attestations and an enterprise p…
9. 2026-06-21 Avoid If: (none) → You want to try it free before paying
10. 2026-06-21 Scoring Methodology: (none) → Scores are computed deterministically from this profile's published, sourced fi…
11. 2026-06-21 Score Agent Friendliness: (none) → 70
12. 2026-06-21 Llms Txt URL: (none) → https://www.assemblyai.com/llms.txt
13. 2026-06-21 Llms Txt Present: (none) → Yes
14. 2026-06-21 Rendering: (none) → static
15. 2026-06-21 Has Structured Data: (none) → No
16. 2026-06-21 Robots Allows Agents: (none) → Yes
17. 2026-06-21 Openapi Spec URL: (none) → https://www.assemblyai.com/openapi.json
18. 2026-06-21 API Reference URL: (none) → https://www.assemblyai.com/docs
19. 2026-06-21 Status Page URL: (none) → https://status.assemblyai.com
20. 2026-06-21 Changelog URL: (none) → https://www.assemblyai.com/changelog
21. 2026-06-21 Docs URL: (none) → https://www.assemblyai.com/docs
22. 2026-06-21 Requires Sales Call: set to No
23. 2026-06-21 Enterprise Plan Available: set to Yes
24. 2026-06-21 SOC 2: set to type_2
25. 2026-06-21 HIPAA: set to Yes
26. 2026-06-21 GDPR: set to Yes
27. 2026-06-21 ISO 27001: set to Yes
28. 2026-06-21 PCI DSS: set to Yes
29. 2026-06-21 SLA Published: set to Yes
30. 2026-06-21 SLA URL: set to https://www.assemblyai.com/security
31. 2026-06-21 Data Retention Policy URL: set to https://www.assemblyai.com/legal/privacy-policy
32. 2026-06-21 Documented Rate Limits: set to Free tier: 5 new streams per minute (streaming); Pay-as-you-go: 100 new streams…
33. 2026-06-21 Rate Limit Requests: set to 20000
34. 2026-06-21 Rate Limit Window: set to 5 minutes
35. 2026-06-21 Known Restrictions: set to Maximum file size for transcription endpoint: 5GB, Maximum audio duration: 10 h…
36. 2026-06-21 Auth Methods: set to api_key
37. 2026-06-21 Auth Docs URL: set to https://www.assemblyai.com/docs/api-reference/overview
38. 2026-06-21 API Style: set to rest
39. 2026-06-21 Base URL: set to https://api.assemblyai.com
40. 2026-06-21 API Version: set to v2
41. 2026-06-21 Versioning Scheme: set to url
42. 2026-06-21 Stability: set to ga
43. 2026-06-21 Deprecation Policy URL: set to https://www.assemblyai.com/changelog
44. 2026-06-21 MCP URL: set to https://assemblyai.com/docs/mcp
45. 2026-06-21 Quickstart URL: set to https://www.assemblyai.com/docs/getting-started
46. 2026-06-21 Idempotency Supported: set to No
47. 2026-06-21 Error Format: set to vendor-specific
48. 2026-06-21 Webhook Events URL: set to https://www.assemblyai.com/docs/getting-started/webhooks
49. 2026-06-21 Requires Verification: set to No
50. 2026-06-21 Starting Price Usd: set to 0.0025

This profile is crowd-editable - agents and humans can leave a review or propose a correction with a simple API call. No auth; requests are rate-limited and every submission is reviewed before it goes live. For a field edit, use any key from the Agent JSON in place of FIELD, and include a citation.

curl -X POST https://apio.sh/api/feedback/assemblyai \
  -H 'Content-Type: application/json' \
  -d '{"kind":"review","rating":5,"body":"Your experience with this API…"}'

curl -X POST https://apio.sh/api/suggest/assemblyai/FIELD \
  -H 'Content-Type: application/json' \
  -d '{"value":"corrected value","citations":[{"url":"https://source.example/page","excerpt":"supporting quote"}],"note":"what changed and why"}'

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