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 OpenAI Whisper
Our take
Pick AssemblyAI if voice-product engineers who will pick Universal-3.5 Pro vs Universal-2 and close the socket. Pick OpenAI Whisper if developers and researchers who will run a checkpoint locally or on a Space and accept open-model quality. Skip AssemblyAI if people who want a local MIT model (OpenAI Whisper) with no vendor invoice. Skip OpenAI Whisper if people who want a hosted voice product with a published
AssemblyAI
Voice AI API (pre-recorded STT
OpenAI Whisper
speech-to-text model you can run locally
Best for
AssemblyAI Hours of audio billed on a rate card
OpenAI Whisper Transcribe or translate speech
Free plan
AssemblyAI $0 · $50, no credit card. Free-tier streaming concurrency 5 new streams/min vs PAYG 100
OpenAI Whisper $0 · mIT. You pay CPU/GPU and disk for the checkpoint
Lowest paid
AssemblyAI Universal-2 (pre-recorded) $0.15
OpenAI Whisper Not published by the vendor
Next step up
AssemblyAI Universal-3.5 Pro (pre-recorded) $0.21
OpenAI Whisper
Coding agent
AssemblyAI Voice Agent API
OpenAI Whisper
Runs where
AssemblyAI
OpenAI Whisper Local or hosted
Watch out
AssemblyAI Streaming bills idle socket time
OpenAI Whisper Local is not free electricity
Last checked
AssemblyAI 2026-10-20 · assemblyai.com/pricing
OpenAI Whisper 2026-10-20 · github.com/openai/whisper
Which one, then?
Pick OpenAI Whisper if
developers and researchers who will run a checkpoint locally or on a Space and accept open-model quality.
Read the OpenAI Whisper page