PolySub — AI Video Subtitle Translator

Dual subtitles with managed PolySub AI, themes, community versions, and live transcription.

PolySub adds bilingual subtitles and translation tools directly to web videos. Open a page with an HTML5 video, choose your language, and PolySub can show the original caption together with a translated line. It stays out of the way on pages without a supported video or caption track. What you can do with PolySub: • Watch with original and translated subtitles together • Start with unlimited Instant translation, or select PolySub AI for a more context-aware translation • Choose subtitle display, size, position, and theme • Look up words in context while you watch • Review, search, and export a bilingual transcript • Start Live Transcribe when a video has no usable captions • Optionally use community subtitle versions and correction tools Your privacy and control matter: • PolySub does not sell data or use it for advertising • Community matching stays off until you enable it • Live Transcribe captures current-tab audio only after you start it • You can turn PolySub off for individual sites PolySub needs access to video pages so it can detect the current player, read captions, show the subtitle interface, and perform the action you request. It does not download video files, bypass subscriptions or DRM, or build a browsing-history profile. Basic Instant translation works without payment. Some PolySub AI and Live Transcribe features require an account and available trial or Pro entitlement. Use PolySub only with video content you are permitted to access.