Coursera and Udemy host tens of thousands of courses. The vast majority are in English. If you don't speak English fluently, you've been locked out of most of them — until now.
What works
SyncDub works inside the Coursera and Udemy HTML5 players. The instructor's voice is captured, translated, and played back in real time. The slides stay in their original language — the dub is overlaid on top of the audio.
Best subjects to start with
- Programming (Python, JavaScript, Machine Learning) — instructors speak clearly and use a lot of repeated vocabulary.
- Mathematics and physics — slower paced, terminology translates 1:1.
- Business and management — straightforward narration.
Settings that help
- Turn on 'Lecture mode' in the extension. It optimises for clear, single-speaker audio.
- Set the dub volume to about 70% of the original. The original helps you connect instructor's words to slides.
- Use the 'speed-down' option if your target language is one where the same content needs more words. The dub plays at 0.85× by default in this case.
What doesn't work (yet)
Coding exercise walkthroughs with lots of on-screen text — the dub follows what the instructor is saying, not what they're typing. Live cohort sessions — we don't yet integrate with Zoom. PDF companion materials are not translated in-place; download them and use your browser's built-in PDF translate.