DuoSub: Subtitle Translator

Watch YouTube in two languages at once.

DuoSub plays a video with two subtitle lines: the original line, and your own language right underneath it. Nothing to download, no subtitle files to hunt for, no settings to fight with.

HOW IT WORKS
1. Bring in a video — paste a link, share it from the YouTube app, or find it in the built-in Browse tab.
2. Choose the language for the second line.
3. Press play. Both lines run with the video, word by word.

WHAT YOU GET
• Dual subtitles — the original on top, your translation below, always in sync.
• 90 languages for the translated line, from Vietnamese, Spanish and Japanese to Arabic, Hindi and Ukrainian.
• Karaoke highlighting that frames the word being spoken, so you never lose your place.
• A full transcript that scrolls along with the video — tap any line to jump to that moment.
• Your subtitles, your way: text size, a colour for each line, karaoke on or off — adjustable without leaving fullscreen.
• A real player: drag the seek bar, tap to pause, swipe for brightness and volume, hold for 2x, lock the screen.
• A library that keeps every video you add, with its subtitles saved on your device so replays start instantly.
• The app itself in 12 languages, switchable any time without a restart.

WHO IT'S FOR
People learning a language from real videos instead of textbook audio. Listeners who want an hour-long podcast to stop being a wall of sound. Students following courses recorded in another language. Anyone reading foreign news and documentaries as they play.

DUOSUB PRO
Free: translate up to 3 new videos a day. Videos that have already been translated open for free and don't use up your daily count.
Pro: unlimited translation, every language, every day.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://duosub-1ae27.web.app/privacy

GOOD TO KNOW
DuoSub works with videos that have captions available. Videos play through YouTube's own player — DuoSub does not download or store video. DuoSub is an independent app and is not affiliated with, endorsed by or sponsored by YouTube or Google.