hearsub

HearSub is a browser extension that gives you live translated captions and AI-generated dubbing for YouTube videos. Instead of waiting for a video to fully process or downloading it, you just play the video and HearSub follows along, generating subtitles in your language and even replacing the original audio with a natural-sounding dubbed version. It supports 42 dubbing languages and works on Chrome, Edge, Brave, and Firefox.

The process is simple: open any foreign-language video on YouTube, pick your target language, and HearSub handles the rest. It detects the source language, translates captions in real time, and keeps everything synced with playback. One standout feature is multi-speaker detection — the dubbing tries to preserve different voices rather than using a single flat voice. The extension also keeps the original background audio intact, so you don't lose the atmosphere of the video.

HearSub is especially useful for learners and professionals who rely on global content. If you follow online courses, coding tutorials, interviews, business news, or documentaries in a language you're not fluent in, this tool removes the friction of constantly pausing to read subtitles. It's also handy for catching up on YouTube Shorts from creators around the world. The extension is currently free for personal use with no daily cap, making it a practical choice for regular viewers.