fstalign
Don’t want to install fstalign? Drop the file here.
The first 20 minutes of any recording are transcribed free: a recording up to 20 minutes transcribes in full, a longer one is previewed, and a pack from $6 (500 minutes) transcribes the rest and opens every export, and credits never expire.
Rev.com's WER + alignment scoring tool over WFSTs.
Best for computing WER with formal/informal-equivalence tables. Pricing: free.
What it is
A C++ tool that aligns hypothesis + reference via WFST and produces detailed error reports. Apache-2.0.
Watch out for: C++ tool only; learning curve.
Install / use
git clone https://github.com/revdotcom/fstalignWhat people actually do with fstalign-style transcription
The tool is the means. These are the jobs — each one priced at published rates, each one wired up on its own page.
Features
| Speaker diarization | No |
| Word-level timestamps | Yes |
| Streaming / real-time | No |
| Languages supported | 1 |
| HIPAA eligible | No |
Links
fstalign vs Whipscribe
| Feature | fstalign | Whipscribe |
|---|---|---|
| Category | Open source | Transcription APIs |
| Pricing | free | $6–$24 one-time packs (credits never expire) · first 20 minutes free |
| Speaker identification | No | Named in the summary, key quotes and chapters |
| Word timestamps | Yes | Yes |
| Streaming | No | No |
| Languages | 1 | 99 |
| Platforms | Linux, macOS | Web, API, MCP |
Alternatives to fstalign
Frequently asked about fstalign
Is fstalign free?
Yes. fstalign is free and open source.
Does fstalign work on Mac, Windows and Linux?
fstalign runs on Linux and macOS. It is not listed for other platforms; check the vendor for anything beyond Linux and macOS.
How do I install fstalign?
Clone and run it from source: `git clone https://github.com/revdotcom/fstalign`. Expect to install its dependencies yourself — the README has the exact steps per OS.
How many languages does fstalign support?
fstalign lists 1 languages.
Does fstalign identify different speakers?
No. fstalign does not label speakers; a conversation comes back as one continuous text. If you need speaker labels, that is a separate tool or a different service.
Does fstalign give word-level timestamps?
Yes — fstalign produces timing per word, which is what subtitle cues and clip boundaries need.
Can fstalign transcribe live audio?
No — fstalign works on finished files, not a live stream.
Is fstalign HIPAA compliant?
fstalign does not claim HIPAA compliance. For PHI, run it on infrastructure you control or choose a service that will sign a BAA.
What are the limitations of fstalign?
C++ tool only; learning curve.
Who is fstalign best for?
Computing WER with formal/informal-equivalence tables.
Does fstalign run offline?
fstalign runs on your own machine — it is open source, so nothing leaves the computer unless you configure it to.
Can I use fstalign in the browser?
No — fstalign is a Linux and macOS application, not a web app. You install it rather than sign in to it.
Where is the fstalign source code?
On GitHub at github.com/revdotcom/fstalign. It is maintained by Rev.com.
What kind of tool is fstalign?
In this directory fstalign is filed under toolkit, evaluation, alignment as a open-source tool.
What are the alternatives to fstalign?
There is a side-by-side page at /tools/fstalign-alternatives comparing fstalign with the closest tools in the same category on price, platform and features.
Whipscribe is a hosted transcription service. If you want transcripts without running infrastructure, paste a URL or drop a file in the form below — you'll have a transcript in seconds.
Transcribe your recordings
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Long recording to get through?
One file up to 10 hours, as an upload or a link: see transcribing a long MP3 or M4A, how to transcribe a podcast and the SRT generator.
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