Pick AssemblyAI if
voice-product engineers who will pick Universal-3.5 Pro vs Universal-2 and close the socket.
Read the AssemblyAI pageAssemblyAI vs Deepgram
Our take
Pick AssemblyAI if voice-product engineers who will pick Universal-3.5 Pro vs Universal-2 and close the socket. Pick Deepgram if voice-app and contact-center engineers who will read a $/minute row and ship an API key. Skip AssemblyAI if people who want a local MIT model (OpenAI Whisper) with no vendor invoice. Skip Deepgram if people who want a local transcribe CLI (OpenAI Whisper) with no vendor bill.
AssemblyAI
Voice AI API (pre-recorded STT
Deepgram
**speech API
Best for
AssemblyAI Hours of audio billed on a rate card
Deepgram Streaming or pre-recorded STT billed per minute
Free plan
AssemblyAI $0 · $50, no credit card. Free-tier streaming concurrency 5 new streams/min vs PAYG 100
Deepgram No free plan
Lowest paid
AssemblyAI Universal-2 (pre-recorded) $0.15
Deepgram Growth $4/yr
Next step up
AssemblyAI Universal-3.5 Pro (pre-recorded) $0.21
Deepgram
Coding agent
AssemblyAI Voice Agent API
Deepgram Nova-3 STT
Watch out
AssemblyAI Streaming bills idle socket time
Deepgram Streaming is metered while the socket is open
Last checked
AssemblyAI 2026-10-20 · assemblyai.com/pricing
Deepgram 2026-10-20 · deepgram.com/pricing
Which one, then?
Pick Deepgram if
voice-app and contact-center engineers who will read a $/minute row and ship an API key.
Read the Deepgram page