Best Free Language Learning Browser Extensions in 2026

Passive vocabulary acquisition while browsing

Vocabo replaces individual words on any page you browse with their translation in your target language. The surrounding sentence stays in your native language, so you always have context. Words are introduced gradually — common ones first — and you can tap any word to save it to a vocabulary bank with audio pronunciation.

The key advantage over every other tool on this list: 249+ languages and no account required. Install, choose your language, and it starts working. If you're learning anything less mainstream than French or Spanish, it's often the only option that actually supports your language.

Best for: Anyone who wants passive learning integrated into daily browsing, especially learners of less-common languages.

Original passive word-replacement extension

Toucan pioneered the word-replacement approach and was excellent before being acquired by Babbel in 2022. It supports around 14 languages and has since shifted to a freemium model. If you're learning a supported language and don't mind signing up, it still works. But for most people looking for a Toucan alternative, Vocabo is the natural next step.

Best for: Learners of major European languages who are already in the Babbel ecosystem.

Dual subtitles and transcripts for Netflix and YouTube

Language Reactor is excellent if you spend a lot of time watching video content. It adds dual subtitles to Netflix and YouTube, lets you click individual words for definitions, and exports vocabulary to Anki. It's a different tool from Vocabo or Toucan — it doesn't work on regular webpages — but it's the best extension for media-based learning.

Best for: People who primarily learn through TV shows, movies, or YouTube.

Click-to-translate with automatic flashcard creation

Readlang takes a more active approach: click any word on a webpage to get a translation, and it automatically builds a flashcard from your lookup. Over time, you accumulate a deck of words from things you actually read. Supports 50+ languages. Requires more deliberate effort than passive tools but suits learners who prefer active engagement.

Best for: Learners who read in their target language and want to turn lookups into structured review.

Comprehensive tool for serious learners using Anki

Migaku is the most feature-rich option on this list and the most complex. It integrates deeply with Anki, shows dictionary lookups inline, and supports immersion learning across web and media. At $9/month it's a meaningful commitment, and it has a significant learning curve. Best suited for dedicated learners who are already using Anki and want a premium immersion setup.

Best for: Advanced learners, Anki users, or those serious enough to invest in premium tooling.

Netflix-style streaming in your target language

Lingopie is more of a streaming platform than a browser extension — it provides TV shows and movies in your target language with interactive subtitles. The browser extension enhances the experience but only works within the Lingopie platform. Worth considering if you want structured video content in your target language.

Best for: Learners who want curated native video content rather than general web browsing.

Dual subtitles for Netflix and Disney+

Remfluent is a streaming tool, not a general web extension. It overlays dual subtitles — the original plus a translation — on Netflix and Disney+, and you can tap a word to see its meaning and pronunciation (with furigana/romaji for Japanese and pinyin for Chinese). It supports 15+ languages. The catch is the pricing: the free tier only covers a few demo episodes, and regular use runs on paid plans metered by processing hours — so “is Remfluent free?” effectively has a “not for real use” answer. That's the wall most people hit before searching for a free alternative.

Vocabo isn't a like-for-like Remfluent replacement — it doesn't do streaming subtitles. It works on the web pages you actually read, teaching words in context as you browse, for free, with no processing-hour caps and 249+ languages. If your learning happens on the web rather than on Netflix, it's the free option; if you specifically want subtitle overlays on streaming, no free tool matches Remfluent there.

Best for: Learners who study through Netflix and Disney+ and don't mind paying past the demo episodes.

Translate-and-save flashcards while you browse

Masterlingo is closer to Vocabo's territory: it works on the pages you browse, but the flow is highlight a word, translate it, and save it as a flashcard, with a spaced-repetition deck that lives on its own site. It supports 49 languages and runs on a freemium model. If you want that deliberate save-and-review loop, it's a fair pick; if you'd rather absorb words passively in context — no deck to manage — and want the widest language coverage for free, Vocabo (249+ languages, no account) is the closer fit.

Best for: Learners who want a flashcard deck built from their real reading and don't need long-tail language support.