Vosk vs NVIDIA NeMo ASR
Both are alternatives to Deepgram. Here's how they stack up — verified facts, no spin.
Also searched as NVIDIA NeMo ASR vs Vosk — same comparison, one verdict.
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.
NVIDIA NeMo ASR
The strongest open streaming and diarization story.
NeMo is NVIDIA's conversational-AI toolkit, and its speech models — the Parakeet and Conformer families — are among the most accurate open options available, with genuine streaming support and a mature diarization pipeline. This is the closest open equivalent to what you are buying from a managed service, including the real-time behaviour that is otherwise the hardest thing to reproduce. Apache-2.0, with the expected trade-off that it is built for NVIDIA hardware and is a heavier framework to adopt.
Side by side
| Vosk | NVIDIA NeMo ASR | |
|---|---|---|
| Sovereignty Score | 95 | 89 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | Apache-2.0 | Apache-2.0 |
| Pricing | Free, Apache-2.0. | Free and Apache-2.0; assumes NVIDIA GPU hardware. |
Vosk edges it on the Sovereignty Score, but the right pick depends on the trade-offs below.
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
NVIDIA NeMo ASR
Strengths
- +Best open streaming performance — the managed services' main advantage
- +Mature speaker diarization built into the toolkit
- +Top-tier accuracy on English benchmarks
- +Apache-2.0 including the model weights
Trade-offs
- −NVIDIA hardware in practice
- −Large framework — heavier to adopt than a single library
- −Fewer languages well covered than Whisper
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Facts verified 2026-08-11. Licenses and pricing change — spotted something out of date? That's a correction we want.