kitio.aiAssemblyAI vs WhisperX
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. WhisperX is completely free, while AssemblyAI is freemium.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Batch and streaming transcription
- Speaker diarization
- PII redaction
- Sentiment and topic detection
- LLM features over transcripts
- Batched fast transcription
- Word-level timestamps
- Speaker diarization
- Subtitle output
- Python and CLI
| Feature | AssemblyAI | WhisperX |
|---|---|---|
| Best for | Speech AI API for transcription, diarization and audio understanding | Fast Whisper transcription with word timestamps and speaker labels |
| Category | Audio & voice | Audio & voice |
| Pricing model | Freemium | Free |
| Starting price | See pricing page | Free |
| Free plan | Yes | Yes, fully free |
| Made by | AssemblyAI | Max Bain |
| Based in | United States | – |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
|
Both offer: Speaker diarization.
Pricing compared
WhisperX is completely free, while AssemblyAI is freemium.
Free plan
Cheapest paid plan
Top plan
Free trial
3 plans
Free
Free
- Try the API for free
- No commitment
Pay as you go
$0.21 / hr (Universal-3.5 Pro)
- Universal-2 at $0.15/hr
- Streaming from $0.45/hr
- Add-ons billed per hour
Custom
Custom
- Custom rate limits
- Higher concurrency
- Enterprise-grade flexibility
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
AssemblyAI
- High accuracy on English
- Rich analysis features
- Clear documentation
- Add-on features cost extra
- No end-user app
WhisperX
- Much faster than stock Whisper
- Accurate word timings
- Speaker labels included
- Diarization needs a Hugging Face token
- Setup requires Python and a GPU
Which one should you choose?
Choose AssemblyAI if you want:
- High accuracy on English
- Rich analysis features
- Clear documentation
Watch out: add-on features cost extra.
Choose WhisperX if you want:
- Much faster than stock Whisper
- Accurate word timings
- Speaker labels included
Watch out: diarization needs a hugging face token.
AssemblyAI vs WhisperX FAQ
What is the difference between AssemblyAI and WhisperX?
AssemblyAI: Speech AI API for transcription, diarization and audio understanding. WhisperX: Fast Whisper transcription with word timestamps and speaker labels. Both are audio & voice tools.
Is AssemblyAI or WhisperX cheaper?
WhisperX is completely free, while AssemblyAI is freemium.
Do AssemblyAI and WhisperX have free plans?
AssemblyAI: Yes. WhisperX: Yes, fully free.
Who makes AssemblyAI?
AssemblyAI is made by AssemblyAI, based in United States.
Who makes WhisperX?
WhisperX is made by Max Bain.
Which should I choose, AssemblyAI or WhisperX?
Choose AssemblyAI if you value high accuracy on english and rich analysis features. Choose WhisperX if you value much faster than stock whisper and accurate word timings.