Introduction
Read Frog translates what you are reading, then turns the parts worth keeping into study material.
Read Frog is an open-source browser extension for reading in a language you are still learning. It translates a page beside its original text, so you can read the source and check yourself against the translation only when you need to.
Two halves
The extension does the reading. It translates whole pages, single paragraphs, selected text, text you are typing, and YouTube captions. It can read aloud, keep your terminology consistent with a Glossary, and run your own Custom AI Actions on anything you select.
The web app at readfrog.app does the learning. Words and explanations you save from the extension land in a Notebase, where you turn them into cards and review them on a schedule. You can also point an AI assistant at your own notes over MCP.
You do not need the second half. Plenty of people install the extension, set one provider, and never sign in — translation works fully without an account.
Start here
Install the extension and add a provider. Google Translate and Microsoft Translator work immediately with no key.
Read Page Translation for the everyday controls — bilingual or translation-only, what counts as page content, and the keyboard shortcut.
Add whatever else you actually need: Video Subtitles for YouTube, a Glossary for terms a model keeps getting wrong, or Custom Prompts if you want to change how translations read.
Open source and community
Read Frog is open source. Bug reports, site rules, and pull requests are all welcome.
Join the Discord for help and discussion, or see Contributing to work on the extension itself.