Descript
Text-based video and podcast editor with AI transcription, voice cloning, and filler-word removal
FREEMIUM Verified JUL 3, 2026
AssemblyAI
Voice AI API for developers: speech-to-text, speaker diarization, audio intelligence, and LLM-over-audio with per-hour usage billing
AssemblyAI is a developer API for speech-to-text and voice AI — async transcription, real-time streaming, speaker diarization, and LLM-over-audio. Pre-recorded transcription starts at $0.15 per hour and streaming at $0.15 per hour, and new accounts get $50 in free credits with no card. Its Universal-2 model covers 99 languages. Best for engineers adding transcription or voice agents to products; it is API-only with no consumer app.
Verified JUN 23, 2026 USAGE-BASED Live
What is AssemblyAI?
AssemblyAI is a developer-focused API for turning speech into text and building voice-driven features. Its core is high-accuracy transcription — both asynchronous, for pre-recorded files, and real-time, for live streaming audio — delivered through the Universal model family. On top of raw transcription it layers speaker diarization, audio intelligence (entity and topic detection, sentiment, summarization, content moderation), and PII redaction, so a single integration can produce structured, searchable output rather than a plain transcript.
More recently the product has expanded into voice AI infrastructure. An LLM Gateway lets you run large language models like Claude and Gemini directly over transcribed audio for question-answering and summarization, and a Voice Agent API bundles transcription, reasoning, speech, and turn detection for conversational applications. Pricing is usage-based: pre-recorded transcription starts at $0.15 per hour, streaming at $0.15 per hour, with add-ons billed on top. New accounts receive $50 in free credits with no credit card, and enterprise plans add HIPAA, SOC 2 Type 2, ISO 27001, and GDPR compliance at no premium.
Who is it for?
AssemblyAI is for engineers and product teams building audio features into their own software. It is deliberately API-only, so it rewards teams that can write code and want control, not end users looking for a finished app.
- Developers adding transcription to meeting tools, media platforms, or accessibility features who need accurate async and streaming speech-to-text.
- Builders of voice agents that must listen, reason over what was said, and respond in real time.
- Call-center and sales-tech teams running analytics — sentiment, topics, PII redaction, summaries — across large volumes of recorded calls.
- Regulated industries that require HIPAA, SOC 2, ISO 27001, or GDPR coverage as part of their audio pipeline.
How much does AssemblyAI cost?
Starting price: $0.15/hr · Free tier: yes · Model: usage-based
Pricing verified JUN 23, 2026
Price history tracked from June 2026
| Plan | Price | Includes |
|---|---|---|
| Free | $50 in credits | $50 in free credits, no credit card required · Covers roughly 185 hours of pre-recorded audio · Limited to 5 new streams per minute |
| Pay-as-you-go | from $0.15/hr | Universal-2 async transcription $0.15/hr; Universal-3 Pro $0.21/hr · Streaming from $0.15/hr; up to 100 new streams per minute · Speaker diarization add-on +$0.02/hr async, +$0.12/hr streaming · Access to all models and audio-intelligence add-ons |
| Enterprise | Custom | HIPAA BAA, SOC 2 Type 2, ISO 27001, GDPR at no premium · Higher concurrency via contract · Volume pricing and dedicated support |
What are AssemblyAI's key features?
- Pre-recorded (async) speech-to-text via Universal-2 and Universal-3 Pro models
- Real-time streaming speech-to-text over WebSocket
- Speaker diarization (who spoke when) as a stackable add-on
- Audio Intelligence: entity and topic detection, sentiment analysis, summarization, content moderation
- PII text redaction and content-moderation guardrails
- LLM Gateway to run models like Claude and Gemini over transcribed audio
- Voice Agent API combining transcription, reasoning, speech, and turn detection
- Official Python and JavaScript SDKs
What people use AssemblyAI for
- 01 Transcribing meetings, calls, podcasts, and video for searchable text and captions
- 02 Live captioning and real-time transcription for streaming audio
- 03 Building voice agents that listen, reason, and respond
- 04 Call-center analytics: sentiment, topic detection, PII redaction, and summarization
- 05 Running LLM queries over audio content for Q and A or summarization
Pros and cons
| Pros | Cons |
|---|---|
| Transparent per-hour usage pricing with no upfront commitment | API and SDK only — there is no web app or no-code UI, so non-developers cannot use it directly |
| Generous $50 free signup credit with no credit card required | Audio-intelligence features are add-ons that stack on the base rate and raise effective cost |
| Broad language coverage (99 languages on Universal-2) plus 100+ translation targets | The newer Universal-3 Pro currently supports far fewer languages than Universal-2's 99 |
| One API spans async, streaming, audio intelligence, voice agents, and LLM-over-audio | In-region model pricing rises 10% from July 1, 2026 unless requests use the global region |
| Enterprise compliance (HIPAA BAA, SOC 2 Type 2, ISO 27001, GDPR) included at no premium | Enterprise pricing is contact-sales only, not published |
What are the best AssemblyAI alternatives?
Otter.ai
AI meeting assistant that transcribes, summarizes and extracts action items from conversations
FREEMIUM Verified JUN 11, 2026
ElevenLabs
AI voice platform for text-to-speech, voice cloning, and conversational agents in 70+ languages
FREEMIUM Verified JUL 3, 2026
Fireflies.ai
AI meeting assistant that transcribes, summarizes, and searches your conversations
FREEMIUM Verified JUL 3, 2026
How people make money with AssemblyAI
- Build a vertical transcription or call-analytics SaaS on AssemblyAI — captioning, meeting notes, or call-center QA — marking up the per-hour API cost into a per-seat subscription
- Offer a podcast and video production service that ships transcripts, chapters, and clips, using audio-intelligence add-ons to differentiate the deliverable
Frequently asked questions
How much does AssemblyAI cost per hour?
Pre-recorded transcription starts at $0.15/hr on Universal-2 and $0.21/hr on Universal-3 Pro. Streaming starts at $0.15/hr, billed by audio duration with audio-intelligence add-ons priced separately.
Does AssemblyAI have a free tier?
Yes. New accounts get $50 in free credits with no credit card required, which covers roughly 185 hours of pre-recorded transcription, capped at 5 new streams per minute.
How many languages does AssemblyAI support?
The Universal-2 model supports 99 languages for pre-recorded audio, and translation supports 100+ target languages. The newer Universal-3 Pro currently covers a smaller language set.
Does AssemblyAI offer speaker diarization?
Yes. Speaker diarization is a stackable add-on, priced at an extra $0.02/hr for pre-recorded audio and $0.12/hr for streaming audio.
What platforms does AssemblyAI provide?
AssemblyAI is an API-first product with official Python and JavaScript SDKs. There is no consumer web or mobile app — it is meant to be integrated into your own software.
Can AssemblyAI run LLMs over audio?
Yes. Its LLM Gateway lets you run models such as Claude and Gemini over transcribed audio, billed per million input and output tokens.