AutoDub

AutoDub is a free browser extension that translates and dubs foreign-language YouTube videos into 42 languages, with 90+ voices, automatic source language detection and bilingual subtitles, for Chromium browsers and Firefox.

AutoDub is a browser extension built for one job: letting people watch foreign-language YouTube videos in their own language. It adds a button to the YouTube player controls. Once a target language is chosen, the extension detects the original spoken language by itself, translates the video's captions, and plays a synthetic voice track over the video, with bilingual subtitles shown on screen. The source video can be in any language, and the dub can be produced in 42 languages, with more than 90 voices to choose from. The tool is aimed at viewers rather than creators. The homepage points to programming tutorials, university-style lectures, documentaries, business talks, lifestyle vlogs and long-form podcast interviews as typical uses, essentially anything a person would want to follow without reading subtitles the whole time. Setup requires no account or sign-in: install the extension from the Chrome Web Store, open a video, pick a language and press play. A manual .crx download is offered, and a separate Firefox version is published on Firefox Add-ons. It runs on Chrome, Edge, Brave and other Chromium browsers, but not Safari. In practice, dubbing depends on the video having a subtitle track. YouTube's auto-generated captions count, so most videos qualify, but a video with no captions at all cannot be dubbed yet. The captions are processed on the developer's servers using Google AI models for translation and neural voices for speech, and results are cached per video rather than per user. An internet connection is required, and a reviewer notes that the audio needs a little time to translate before playback feels smooth. Among alternatives, AutoDub sits between plain subtitle translators and creator-side dubbing services. It does not edit or export dubbed files, and it is limited to YouTube, though other platforms are described as under consideration. The service is currently free for personal use with no daily limit, with a promise of advance notice if paid features ever arrive.