InterSub

InterSub is a smart browser extension that turns your favorite shows and online courses into fun, interactive language lessons. Whether you’re watching Netflix, YouTube, Prime Video, TED, Coursera, Udemy, or even LinkedIn Learning, InterSub helps you learn new languages by adding interactive dual subtitles—so you see both your native language and the target language side by side.

Using AI-powered translations, InterSub makes it effortless to understand and remember new words. Just hover over any word in the subtitle, and you’ll instantly get a clear definition along with a contextual translation. It even saves every word you translate into your personal wordbook, so you can easily review and practice later.

For those who want to learn on the go, InterSub supports syncing with Anki, Telegram bots, and other mobile apps. And if you’re watching on a TV or large screen, you can even use your phone as a remote control to look up translations without interrupting the video.

The extension also recognizes idioms, phrasal verbs, and collocations, so you learn natural language—not just dictionary definitions. A unique feature like “Show Subtitles on Pause” lets you focus on the content without constant reading, and then catch up only when you pause.

And the best part? With the 14-day free trial, you get unlimited access to dual subtitles—a great way to start learning a new language while enjoying your favorite content. Dive in and experience language learning the smart and enjoyable way with InterSub.