AssemblyAI
Multilingual Speech-to-Text API with near-human accuracy.
At a glance
Price not confirmed · Source review 2026-10-24- Price & billing
Free tier: $50 in credits, no credit card required. Pay-as-you-go from $0.15/hour of audio (Universal-2); Universal-3 Pro $0.21/hour; streaming and add-ons priced separately; Voice Agent API $4.50/hour flat. Prices as of Oct 2026 — verify on the official pricing page.
- Free allowance
Free tier: $50 in credits, no credit card required.
- Best suited to
Development teams building transcription, meeting-intelligence, call-analytics, or voice-agent products who want one vendor for speech plus audio understanding. The per-hour pricing and official Pytho
Fit is editorial guidance, not a measured result.- Platforms
Access: not separately verified. Operating systems not separately verified.
Published-source facts and editorial guidance. No product test is implied. Confirm current conditions before purchase.
No product screenshot is claimed for this listing. Use the official website ↗ to inspect the current interface.
What to know before choosing
Good fit
Development teams building transcription, meeting-intelligence, call-analytics, or voice-agent products who want one vendor for speech plus audio understanding. The per-hour pricing and official Pytho
Limits and trade-offs
Pricing is usage-based, so costs scale with audio volume — forecast before committing to streaming. Add-ons like diarization and medical mode bill on top of the base rate. Free-tier concurrency is lim
Plans and free allowances
Free tier: $50 in credits, no credit card required. Pay-as-you-go from $0.15/hour of audio (Universal-2); Universal-3 Pro $0.21/hour; streaming and add-ons priced separately; Voice Agent API $4.50/hour flat. Prices as of Oct 2026 — verify on the official pricing page.
Evidence
Official website ↗ (reviewed 2026-10-24)
Official published documentation reviewed; not a product test
Dates: Last reviewed 2026-10-24. Last reviewed is the latest source or editorial review date; it is not a content-change date.
A closer look at AssemblyAI
AssemblyAI is a developer speech-to-text API for transcribing pre-recorded and live audio at scale. Its Universal models cover 99+ languages for async transcription and real-time streaming over WebSocket, with stackable add-ons such as speaker diarization, PII redaction, sentiment analysis, entity detection, and summarization returned in the same payload. It also sells a flat-rate Voice Agent API that bundles transcription, an LLM, and speech into one WebSocket.
Editorial guidance based on published documentation. The workflow below is a suggested starting point, not a measured product result.
When to choose AssemblyAI
- Development teams building transcription, meeting-intelligence, call-analytics, or voice-agent products who want one vendor for speech plus audio understanding.
- The per-hour pricing and official Python/JavaScript SDKs suit production pipelines with predictable audio volumes.
When to choose something else
- Not for non-developers — it is API-only, with no consumer app or no-code studio.
- Also a poor fit if you only need occasional one-off transcripts.
- the free credits cover testing, but the platform assumes you are building a product.
A practical starting workflow
- Sign up and grab an API key (free credits, no card required).
- Send an audio file URL or upload for async transcription, or open a WebSocket for streaming.
- Enable add-ons you need (diarization, PII redaction, summarization).
- Parse the JSON response and pipe transcripts plus labels into your app or analytics.
Check before committing
- Pricing is usage-based, so costs scale with audio volume — forecast before committing to streaming. Add-ons like diarization and medical mode bill on top of the base rate. Free-tier concurrency is limited (around 5 new streams per minute), and model names and rates change as new Universal versions ship.
- Pricing and feature availability may change; confirm current terms on the official website before committing.
Common questions
Is AssemblyAI free?
New accounts get $50 in free credits with no credit card required, which covers roughly 185 hours of pre-recorded transcription. Ongoing use is pay-as-you-go from $0.15/hour of audio.
How much does AssemblyAI cost per hour?
Pre-recorded transcription starts at $0.15/hour (Universal-2); Universal-3 Pro is $0.21/hour. Real-time streaming costs more, and add-ons like speaker diarization or medical mode are billed separately. Enterprise plans get volume discounts.
Does AssemblyAI do real-time transcription?
Yes. It offers streaming speech-to-text over WebSocket with sub-second latency, plus streaming speaker diarization, and a separate Voice Agent API at a flat $4.50/hour that bundles STT, an LLM, and TTS.
Compare approaches for this task
- Deepgram — Developers building voice agents, transcription, or text-to-speech features who want usage-based API pricing.
- Transkriptor — Transkriptor transcribes audio to text in 100+ languages with claimed 99% accuracy, speaker diarization, summaries, action items and an Ask Transkriptor search across the transcript library, plus integrations with Zoom, Teams, Meet and calendars.
- WhisperTranscribe — People with meetings and recordings to turn into text, since WhisperTranscribe offers automatic meeting recording, speaker recognition, and chat with your audio.; Multilingual transcribers, since the product transcribes in 55 languages with Whisper AI.
- Sembly AI — Consultants who turn meeting and project context into branded proposals, case studies, or agreements.
Sources and checks
Last source review is not a date of product testing. No rating or test result is implied by inclusion. Check the current plan and terms before buying.