OpenSubs

What is OpenSubs?

OpenSubs is a free subtitle generator that runs entirely in your browser. Drop in a video file and it transcribes the speech with Whisper on your own machine, then lets you edit, translate, style and export the subtitles. The video is never uploaded: there is no upload endpoint in the product.

Features

Local speech recognition. Whisper runs in the browser tab (WebGPU when available, otherwise WebAssembly). Pick a model from 40 MB to 250 MB; it downloads once and is cached.
Automatic language detection. Or set the spoken language yourself.
Edit every line. Fix the text of any subtitle before you export.
Translate subtitles into 20 languages. In Chrome this runs on your device for free, using the browser's built-in translation. Timings stay unchanged.
Caption styles. Choose a preset, add word-by-word highlighting, and preview it over your own footage.