InterSub

InterSub is a Chrome extension that transforms how you learn languages through video content. It adds interactive dual subtitles to popular streaming platforms like Netflix, YouTube, Prime Video, HBO Max, and educational sites like Coursera and Udemy. The tool displays subtitles in both your target language and native language simultaneously, creating an immersive learning experience without interrupting your viewing.

What makes InterSub stand out is its intelligent AI-powered features. When you hover over any word in the subtitles, it instantly provides definitions and context-aware translations. The system automatically detects and handles complex language elements like phrasal verbs, idioms, and compound nouns. All translated words are saved to your personal wordbook for later review, and you can sync this vocabulary with mobile apps like Anki for studying on the go.

This tool is perfect for language learners who want to make their entertainment time more productive. Whether you're watching Spanish dramas on Netflix, German documentaries on YouTube, or taking an English course on Udemy, InterSub helps you build vocabulary naturally from context. It's particularly valuable for intermediate learners who understand basic grammar but need to expand their vocabulary through authentic content consumption.