Readfrog
Readfrog is an open-source AI bilingual translation browser extension. It supports bilingual contrastive translation for web pages, YouTube, X and e-books. You can click on words for explanations and save new words, and review them with FSRS flashcards on time.
Updated: 2026-10-26
What is Readfrog?
Peidu Wa is an open-source AI bilingual translation plugin. Officially, it allows users to perform bilingual contrastive translation while browsing webpages, videos, and e-books, and supports word selection for AI explanations. Different from ordinary translation plugins, it connects a closed loop of "reading—saving words—reviewing": selected text can be saved as notes, and then the FSRS memory algorithm is used to generate flashcards for regular review. It is positioned as a language learning tool rather than a mere translator.
Who is it for?
- Self-learners who learn languages by watching foreign webpages and YouTube videos and want to accumulate new words effortlessly to reduce barriers.
- Students and readers who are reading English e-books and need side-by-side translation without interrupting their reading flow to stay immersed.
- Candidates preparing for exams who want to use spaced repetition to replace rote memorization and build a personal vocabulary bank for scientific review.
- For tech-savvy users who want open-source plugins and bring their own model API keys to control costs and privacy, with full autonomy and control.
- Language teachers and learners who need to turn scattered foreign language materials into reviewable flashcards.
Key features
6Bilingual Parallel Translation
The official states that the translated text is displayed alongside the original text, fully retaining the original layout of the webpage, and supports full-page or paragraph-by-paragraph translation.
Word-wise AI Explanation
Select any text to run custom AI instructions for various operations such as looking up words, polishing text, and converting time zones.
Vocabulary Note Library
The official version allows you to one-click save words and sentences into the note library, automatically generate review flashcards, and accumulate vocabulary.
Spaced Repetition
Adopts the FSRS memory algorithm to schedule the next review right before the information is about to be forgotten, improving the efficiency of long-term memory retention.
Multi-scenario Support
Covers web pages, YouTube, X, and e-books. The official states that support for PDFs and comics is upcoming, with scenarios being expanded.
Multi-model and Multi-language
It is claimed by the official that the plugin supports 179 languages and more than 30 AI providers (such as OpenAI, DeepSeek, Gemini, Ollama).
How to use Readfrog
- 1**Connect your own model first**: The plug-in requires configuring the API key of the AI provider. First, use the free or your own quota to verify the effect and speed.
- 2**Use hover shortcut keys**: Hover over a paragraph with the default Ctrl key to translate it individually, avoiding page refreshes that disrupt your reading rhythm.
- 3**Review flash cards regularly**: Unify new words encountered in daily life into the note library, and stick to the review according to the FSRS rhythm to be effective.
- 4**Authorization and Compliance**: When using third-party models, pay attention to their data policies and usage fees, and confirm before commercial use or large-scale calls.
- 5**Official rules may be adjusted**: The supported platforms, languages and models may change; please check the latest official website instructions before use.
Traffic & popularity
Data month Sep 2026
Readfrog receives about 270.0K visits per month and ranks #110,528 worldwide.
Monthly visits
12 monthsTraffic sources
- Direct71.5%
- Search12.9%
- Social9.7%
- Referrals5.3%
- AI assistants0.6%
Top countries
- China51.4%
- Taiwan, China13.0%
- Hong Kong, China12.2%
- United States9.0%
- Singapore8.7%
Estimated from third-party traffic data.
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