CaptionGo – Live Captions & Dual Subtitles

What can CaptionGo do?

CaptionGo is a bilingual subtitle and AI live caption extension for Chrome, Edge, Firefox, and mobile browsers. It adds dual subtitles (original + translation) and real-time AI captions to any web video — streaming sites, online courses, live streams, video calls, and more. Works on mobile and in fullscreen. Designed for language learners, students, and anyone watching foreign-language content.

Unlike tools that only translate an existing subtitle track, CaptionGo shows the original subtitle and its translation at the same time — and when a video has no captions at all, it transcribes the speech into real-time live captions using AI speech recognition (ASR).

Core features are free forever, with an optional PRO upgrade.

Free

• Bilingual subtitles (Basic): turn on a site's captions and CaptionGo appends a translation line in place — ideal for learning a language by watching videos or learning English with TV shows and movies.
• Free translation engines: a built-in on-device translator plus Google and Microsoft.
• Automatic captions: turns on a site's own closed captions (CC) the moment playback starts, with per-site rules.
• Live captions (speech-to-text): a free daily allowance transcribes audio for videos with no subtitles, using AI speech recognition (ASR).

PRO

• Advanced bilingual subtitles: read the original subtitle data for preloaded, no-wait, full-sentence translation on a dedicated overlay.
• Full subtitle customization: font, size, color, background, outline, and on-screen position.
• AI subtitle translation: connect your own AI provider such as OpenAI, Gemini, and DeepSeek for natural, context-aware results.
• More live captions (ASR): extra usage and the option to use your own speech-to-text key.
• Cross-device sync: end-to-end-encrypted cloud sync — set everything up on your computer, then just install and sign in on your phone.

What sites are supported?

Works across the web — streaming sites, Bilibili, Coursera, Udemy, TED, Twitch, X (Twitter), Zoom web, and any site with an HTML5 video player. Also works on mobile browsers (Android Firefox, Android Edge) and in fullscreen mode.

Who is CaptionGo for?

• Language learners — learn English (or any language) by watching videos with bilingual subtitles and AI translation
• Students — auto-generated live captions for online courses, lectures, and educational videos
• Live stream & meeting viewers — real-time AI captions for Twitch, X Spaces, Zoom, and any live content without subtitles
• Foreign content viewers — dual subtitles for movies, anime, K-dramas, news, and livestreams in any language
• Subtitle-less content — AI speech recognition generates real-time captions for videos without subtitles

Install CaptionGo to add bilingual dual subtitles and AI live captions to any video.