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Free Offline Subtitles with Local Whisper

Whisper can run entirely on your own computer: no upload, no API key, no internet. Here is which model to pick and what to expect.

You can make subtitles completely offline by running a Whisper speech-to-text model on your own computer. Download the model once, and from then on transcription needs no internet, no account and no API key, and your video never leaves your machine. The trade-off is speed: your computer does the work a cloud service would.

What Whisper is

Whisper is an open speech-recognition model released by OpenAI. It is available in several sizes, and optimized versions such as whisper.cpp run on ordinary computers without a special graphics card.

Which model to pick

ModelDownloadGood for
Tinyabout 75 MBQuick drafts and testing
Baseabout 142 MBClear speech, short clips
Smallabout 466 MBA good everyday balance
Mediumabout 1.5 GBAccents and noisier audio
Large-v3 Turboabout 1.6 GBClose to Large-v3, several times faster
Large-v3about 3 GBThe most accurate

If you are not sure, start with Large-v3 Turbo. Drop to Small if transcription is too slow on your computer.

When offline makes sense

  • Private footage: client work, unreleased episodes, classroom recordings.
  • No reliable internet: travelling, on location, or on a metered connection.
  • No accounts: no provider sign-up and no key to manage.

When a cloud engine is better

On a slower computer, or for long videos, a cloud engine such as Groq is much faster, and Groq has a free tier. The trade-off is that the extracted audio (not the video) is sent to the provider.

Offline subtitles in Captixa

  1. Open Settings and set the transcription engine to Local Whisper.
  2. Click Download next to a model.
  3. Load a video and click Transcribe. Then style it and export an MP4 with captions, or an SRT.

Everything after the model download, from transcription to export, runs without an internet connection.

Is local Whisper really free?

Yes. The models are free to download and run on your own computer. There is no key and no per-minute cost.

Is it as accurate as cloud transcription?

The larger local models are close. Large-v3 is the most accurate local model; Large-v3 Turbo is close to it and several times faster. Smaller models trade accuracy for speed.

Does anything need the internet?

Only the one-time model download. After that, transcribing, styling, editing and exporting all work offline. Translation and Roman-script conversion still need a connection.

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