Rikaitan by Ren Tatsumoto

Rikaitan is a browser extension that lets you look up words on web pages (a pop-up dictionary). Rikaitan is free/libre software maintained by the AJATT community — anyone can contribute.

Rikaitan turns your web browser into a tool for building proficiency in your target language. It helps you decipher texts in 20+ languages, making difficult texts understandable.

Rikaitan provides powerful features not commonly found in other browser dictionaries:

🗽 Libre software.
💬 Interactive popup window for dictionary definitions.
🔍 Search page for looking up words easily.
🌎 Support for 20+ languages, from Japanese and Spanish to Arabic.
🔊 Native pronunciation audio from multiple sources, with support for custom audio sources.
📝 Automatic flashcard creation for the Anki flashcard program.
📚 Add multiple dictionaries from recommended and custom sources. Slang, kanji, and pronunciation dictionaries. There are thousands of available dictionaries online.
☁️ Fully offline operation — no internet connection required.
🛡️ Privacy-conscious: by default we transmit only the minimum data outside the extension (for example, only the single word you request and only when you press the audio playback button). All data transmission settings are configurable; see the privacy policy for details.

After installing Rikaitan, please read the manual to better understand how to use the add-on. More info: Rikaitan Wiki.