
Whisper
✓ Editorially verifiedOpenAI's open-source speech-to-text — the de-facto baseline.
In short
Whisper is OpenAI's free, open-source speech-to-text model supporting 99 languages. It offers strong baseline accuracy for self-hosting or via API, though it lacks built-in diarisation.
Pick Whisper when you can self-host (or the OpenAI API is fine) and want strong baseline transcription at near-zero per-hour cost.
Skip it when you need turnkey diarisation, summarisation, or streaming — AssemblyAI is built for that.
Whisper is OpenAI's open-source speech recognition model. It's free to self-host, multilingual (99 languages), and the baseline against which every other STT model is measured. The large-v3 release is genuinely competitive with paid alternatives on accuracy.
For anyone with engineering capacity, Whisper is the default. Self-hosted, it costs effectively nothing per hour of audio. Available via OpenAI's API for those who don't want to operate a GPU. Hugging Face Transformers makes integration straightforward in Python.
The model has no built-in diarisation — speaker labels need a separate pipeline (pyannote, etc.). Hallucinations on silent segments are a known issue and require post-processing to clean up. For production pipelines these are solvable; out of the box they're surprising.
Whisper is the rare OpenAI release that's open-weight and excellent. It set the standard for what speech-to-text should cost, and it remains the right default for almost any team with engineering capacity.
— The AI Tool Bible editorial team
Pros
- ✅ Free, open weights
- ✅ Multilingual (99 languages)
- ✅ Strong baseline accuracy
- ✅ Available via API or self-host
Cons
- ⚠️ No diarisation built in
- ⚠️ Hallucinations on silent segments
Use cases
Frequently asked
- How much does Whisper cost to use?
- Whisper is free to self-host with open weights. If you use the OpenAI API, the cost is $0.006 per minute. For those with engineering capacity, self-hosting results in effectively zero per-hour cost.
- Does Whisper support multiple languages?
- Yes, Whisper is multilingual and supports 99 languages. It is considered the de-facto baseline for speech recognition and is genuinely competitive with paid alternatives on accuracy, particularly the large-v3 release.
- Can Whisper identify different speakers automatically?
- No, the model has no built-in diarisation. Speaker labels require a separate pipeline, such as pyannote. If you need turnkey diarisation, summarisation, or streaming, AssemblyAI is a better alternative.
- Is Whisper easy to integrate into my project?
- Integration is straightforward in Python using Hugging Face Transformers. It is available via OpenAI's API for those who do not want to operate a GPU, making it accessible for various engineering capacities.
- Are there any known issues with Whisper?
- Hallucinations on silent segments are a known issue that requires post-processing to clean up. While these are solvable in production pipelines, they can be surprising out of the box.
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