Vosk vs Whisper
Both are alternatives to Deepgram. Here's how they stack up — verified facts, no spin.
Also searched as Whisper vs Vosk — same comparison, one verdict.
Vosk and Whisper are closely matched on ownership (95 vs 94) — this one comes down to pricing and to which trade-offs below you can live with.
Vosk
Real-time transcription on a CPU. Runs on a Raspberry Pi.
Vosk is a lightweight offline speech-recognition toolkit built for constrained environments — it runs in real time on a CPU, works on Android, iOS and single-board computers, and its models are tens of megabytes rather than gigabytes. It will not match Whisper on accuracy for difficult audio. It is the right answer when you need speech recognition on a device, offline, with no GPU and no network, which is a requirement no managed API can satisfy at any price. Apache-2.0.
Whisper
The model that changed the category. MIT, and free to run forever.
Whisper is OpenAI's speech-recognition model, released openly under MIT — weights included. It handles around a hundred languages, is robust to accents and background noise, and does translation as well as transcription. Releasing it is what collapsed the economics of this category: a model competitive with the commercial APIs became something anyone could download. The reference implementation is slower than the optimised runtimes, but it is the simplest thing that works and the baseline everything else is measured against.
Side by side
6 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| Vosk | Whisper | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 95 | 94 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | Yes | Yes |
| License | Apache-2.0 | MIT |
| Pricing | Free, Apache-2.0. | Free — model weights and code both MIT. |
Vosk edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
Weighing both against staying on Deepgram? Is Deepgram free? What it actually costs →
Vosk
Strengths
- +Real-time on CPU — no GPU required at all
- +Tiny models; runs on phones and single-board computers
- +Fully offline, which some products require by law
- +Around twenty languages supported
Trade-offs
- −Noticeably less accurate than Whisper on hard audio
- −Smaller language coverage
- −No built-in diarization
Whisper
Strengths
- +Genuinely open weights under MIT, not a restricted community licence
- +About a hundred languages, robust to noise and accent
- +Reference implementation — simplest possible starting point
- +Translation to English included
Trade-offs
- −Slower and hungrier than faster-whisper for identical output
- −Weak word-level timestamps without help
- −No speaker diarization
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose Vosk
if a lower exit cost matters more to you than any single feature, and real-time on CPU — no GPU required at all.
Choose Whisper
if genuinely open weights under MIT, not a restricted community licence.
Neither, yet
if both carry a real cost you should weigh first — noticeably less accurate than Whisper on hard audio, and slower and hungrier than faster-whisper for identical output. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
Vosk vs Whisper — common questions
Is Vosk a better fit than Whisper for speech recognition & transcription?
It depends on what you are optimising for, and the honest split is this: Vosk scores 95 to Whisper's 94 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. Whisper earns its place on a different axis — genuinely open weights under MIT, not a restricted community licence. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
Vosk keeps its data local or in open formats, so leaving is an export rather than a negotiation. Whisper is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host Vosk or Whisper?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are Vosk and Whisper both alternatives to Deepgram?
Yes — both appear in our Deepgram comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off Deepgram and now choosing between the two replacements, which is a narrower and much easier question.
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Facts verified 2026-08-11. Licenses and pricing change — spotted something out of date? That's a correction we want.