Best browser extensions for learning languages

Yomitan is a pop-up dictionary for the web. Point at a word on any page and a window shows its definitions, readings and pronunciation audio. It began as Yomichan, a Japanese reader that its creator shut down in February 2023, and a community team took over the code as Yomitan. It now handles more than 20 languages, and it is free and open source.

It supports several dictionary formats, so a lookup can show the sources you trust. Kanji stroke order is a click away, and a custom search page lets you query directly. If you use Anki, one keypress sends a lookup to your deck as a flashcard. asbplayer, also on this list, recommends pairing with it.

The trade-off is setup. You choose and configure your dictionaries, and flashcards need Anki with the AnkiConnect add-on. It asks for access to all websites to read the text under your cursor, and its documentation says it also requests audio and connects to Anki. We found no Safari version. If you read in your target language and will configure a tool once, start here.

Language Reactor is the best-known tool for learning from streaming video. It was previously called Language Learning with Netflix. On Netflix it shows two subtitle tracks at once, one in the language you are learning and one in your own, and a click on any word opens a pop-up dictionary. It also works on YouTube, and you can paste in text or books to get a machine translation and spoken audio.

It is built for study rather than casual viewing, with precise playback controls on Netflix. The extension can be used for free and the listing shows in-app purchases, while the developer's forum describes a paid Pro mode. You still need your own Netflix subscription.

Read the small print first. The code is closed. Its privacy policy says it collects an anonymous browser ID, your Chrome account email, your Netflix country and language and subtitle counts, and shares none of it with third parties, but it names no company and still uses the old product name. In February 2026 its forum said no official Firefox version had been released, so a Firefox add-on carrying its name looks unofficial. Install it only from the Chrome Web Store.

asbplayer is a subtitle player built for sentence mining, the habit of learning a language by collecting full sentences from shows you enjoy. It makes subtitles on a video selectable text, so a dictionary tool can look up any word. It then turns a line into an Anki flashcard that includes the audio and a screenshot from the scene.

It works on two kinds of video. On popular streaming sites such as Netflix and YouTube it detects the subtitles automatically. For other sites, its README says a fallback detector finds subtitles on about 85 per cent of them, and you can always load your own subtitle files. It can also colour words by how well you know them, using data from Anki or WaniKani. The project is open source under the AGPL, and the developer's listing says it will not collect or use your data.

The cost is setup. Its own guide has you install a dictionary extension such as Yomitan, install Anki, add the AnkiConnect plugin and then configure asbplayer to use your deck. It does not translate for you or teach, so it suits learners who already follow a method. If that is you, it is the best free way to turn video into flashcards.

10ten Japanese Reader, formerly called Rikaichamp, is a pop-up dictionary for Japanese. Hover over text on any page, or tap on a phone, and it shows the word, its reading and its meaning. It is made by Birchill, Inc., it is free and open source under the GPL, and it is the only pick here with a Safari version.

Its depth is in Japanese. The App Store description lists pitch accent, recognition of many grammatical forms, vertical text, conversion of Japanese-era years and yen amounts, and automatic previews of names. Dictionaries update automatically, at least weekly, fetching only the changed entries. Beyond Chrome and Firefox it has an Edge listing and a Safari app, which the developer says works on a phone. In the Chrome listing the developer declares that it does not collect or use your data.

The trade-off is scope. It looks words up and does little else: no subtitles, courses or study plan, and only Japanese. Like any pop-up dictionary it needs access to the pages you read. If you learn Japanese and want one tool across Chrome, Firefox and Safari, choose this.

Zhongwen is a pop-up dictionary for Chinese. Hover over a character or word on any page and a small window shows the pinyin and the English meaning. It is made by Christian Schiller, it is free and open source under the GPL, and it uses the widely used CEDICT Chinese-English dictionary.

The features are aimed at learners. It supports simplified and traditional characters and can show only one set. Pinyin syllables are coloured by tone. You can move the pop-up to the next character or word from the keyboard, and it links to the Chinese Grammar Wiki. You can add words to a built-in list and export it as a text file, for example for Anki, and it can send words to Skritter.

It is deliberately simple. It has no lessons, subtitles or spaced repetition of its own, and covers Mandarin to English only. When we checked, the Firefox listing was on an older version than Chrome's. The developer declares in the Chrome listing that it does not collect or use your data, and it needs access to the pages you read. For a light Chinese lookup tool that stays out of the way, try this.

Readlang Web Reader lets you read websites in the language you are learning and look up the words you do not know. Click the R button, then click a word or drag across a phrase to see a translation. Readlang then builds flashcards and vocabulary lists from what you looked up. It is made by Steve Ridout, who says on the site that he was previously a staff software engineer at Duolingo.

The extension is the front end for the Readlang service, which also has an online reader, iOS and Android apps and bookmarklets. The free plan includes unlimited single-word translations, with daily limits on phrase translations and context explanations. Flashcard practice and book export are on the paid plans, and one subscription covers every language. A right-click option sends a plain-text version of a page to the Readlang reader.

The code is closed. Its Chrome listing says the extension handles personally identifiable information and website content, and the developer declares it does not sell that data. Its Firefox permissions include access to all websites. The Chrome rating of 4.2 rests on a few hundred ratings, so there is less evidence than for the bigger tools here. For a reading-first tool that handles the flashcards, it is a reasonable pick.

Migaku is a paid language-learning system, and the browser extension is one part of it. You click words in subtitles or on web pages, and Migaku shows what they mean and builds a flashcard with media from the page. Its Chrome listing names YouTube, Netflix, Disney+, Rakuten Viki and Animelon as supported video sites, with apps for iOS and Android.

The pitch is a full path. Beginners can follow its courses, currently Japanese, Mandarin and Korean per the listing, then move to real content. It supports ten languages in all, including Spanish, Portuguese, French, German, Cantonese and Vietnamese. Migaku Inc. lists a US address and identifies itself as a trader. The older Migaku Legacy extension is marked deprecated.

There are trade-offs. The extension is closed source, needs a Migaku account and is a paid product, with a free trial and a lifetime offer promoted on its site. The Chrome listing says it handles user activity and website content. Its privacy policy covers account, usage and device data, and shares hashed email addresses with Meta and Google for ad attribution, though it says language-learning progress is not shared or sold. We found a Chrome Web Store listing only. For one paid system instead of assembled free tools, this is the pick.