I built SubDuo because I kept doing the same clumsy loop while trying to study English from shows: pause, open the subtitle menu, switch the track, rewind, switch back. Every pause broke the story, and I stopped finishing anything I started. So SubDuo just shows both at once — the original language on top, your own language underneath — on Prime Video, YouTube, Netflix and Disney+. You can drag the lines wherever they don't cover faces, scroll to resize each line independently, and set color and opacity so they don't fight the picture. It remembers your setup per site and syncs it across your Chrome devices. YouTube auto-generated captions work too, so it isn't limited to titles with official subs. Free, 12 languages, no sign-up, and everything runs locally in the browser. I'd love to know which service you'd want supported next, and whether the two-line layout holds up on your screen size — that's the part I've tweaked the most.

SubDuo

Dual subtitles for Netflix, YouTube, Prime Video & Disney+

Dual subtitles for Netflix, YouTube, Prime Video & Disney+