Read Frog: A Browser Extension That Turns Translation into Language Learning
🐸 Read Frog - Language Learning & Translate | 🐸 陪读蛙 - 语言学习与翻译
At a glance
- What is it?
- Read Frog is an open-source browser extension that layers AI translation, bilingual reading, and learning tools on top of ordinary web pages. It supports over 20 AI providers and targets language learners who want more than a plain machine translation.
- Who is it for?
- Language learners who read foreign-language articles, watch subtitled video, or want sentence-level analysis in the browser should consider Read Frog. It is not the right tool if you need a simple, no-config translation tool or if you want to avoid sending page content to third-party AI APIs.
- Can I use it commercially?
- Yes, with conditions. GPL-3.0 is a copyleft licence: if you distribute software that includes it, you must release that software's source code under the same licence. Running it internally without distributing it does not trigger that obligation.
- Is it still maintained?
- Yes. The repository last received commits 1 day ago.
- What is it written in?
- Mainly TypeScript, according to GitHub's language statistics.
Answers come from the project's GitHub data, last synced on September 15, 2026, and from our analysis. They are not legal advice.
DEEP OPEN-SOURCE ANALYSIS
What Read Frog Actually Does
Read Frog is a browser extension that repositions translation as a language-learning aid rather than a pure conversion utility. The README describes features like bilingual or translation-only page views, selection translation, context-aware translation, subtitle translation, and text-to-speech (TTS). It also supports batch requests and more than 20 AI providers, including OpenAI and DeepSeek, judging by the listed topics. The intended user is someone who reads foreign-language content daily and wants to understand not just what a sentence means but how it fits the surrounding text. The extension is distributed for Chrome, Edge, and Firefox, with a homepage at readfrog.app. The project is written in TypeScript and uses the WXT framework, which is a modern tool for building cross-browser extensions.
How the Extension Turns Reading into a Study Session
The core mechanism is not a single translation call but a set of modes that change how a page is displayed. Bilingual mode shows the original text alongside a translation, which lets a learner compare the two. Translation-only mode replaces the page content entirely. Context-aware translation is the more interesting piece: instead of translating a sentence in isolation, the AI receives surrounding text so that pronouns, technical terms, and idiomatic phrases are handled correctly. The README also mentions custom AI actions, where a user can turn selected text into reusable tools. That suggests a workflow where you define prompts or operations once and apply them to any highlighted text on any page. Subtitle translation and TTS extend the tool to video and audio, which makes it useful for watching foreign-language content. Batch requests are mentioned, which likely means the extension groups multiple sentences into fewer API calls to reduce latency and cost, though the exact grouping logic is not described.
Getting Started: Installation and Configuration
The README provides direct download links for the Chrome Web Store, Microsoft Edge Addons, and Firefox Add-ons. There is also a mirror link for users in mainland China. After installation, the user must configure an AI provider. The extension supports over 20 providers, which implies that you can bring your own API key or select a default service. The homepage and tutorial at readfrog.app/docs contain setup instructions. The repository is under active development, with recent releases v1.46.9, v1.46.8, and v1.46.7 pushed in September 2026. That cadence suggests a project that ships new features frequently, but it also means the configuration UI may change between versions. The README does not list exact configuration keys or command-line setup steps, so a new user should rely on the tutorial site. Developers who want to build from source would need to clone the repository and follow the standard WXT workflow, but no specific commands are given in the supplied material.
The Learning-First Approach vs. Plain Translation
Read Frog's positioning is distinct from a tool like Google Translate or a typical browser translation popup. Those tools aim to remove the friction of reading a foreign language. Read Frog aims to keep some of that friction visible, for example by showing both the source and the translation side by side. That is a deliberate design choice that suits learners but can annoy someone who just wants to read an article quickly. The context-aware translation feature is a genuine improvement over sentence-level translation, because many errors in machine translation come from missing context. However, the README does not explain how the context is selected or how long the context window is. That matters because a long article could exceed the model's token limit, and a short context might not resolve ambiguity. The extension does not appear to offer a built-in dictionary or spaced-repetition system, which are common in dedicated language-learning apps. So it is a reading aid, not a full learning management system.
Where Read Frog Falls Short
The most obvious limitation is that it depends on external AI providers. If you use a paid API like OpenAI, every translation costs money and sends the page text to a third party. That raises privacy concerns for sensitive content, such as personal emails or confidential documents. The README does not state a privacy policy or data retention details. Another limitation is that the extension is under active development, so bugs and breaking changes are likely. The README itself says it is currently under active development and welcomes feedback on issues. This is not a criticism, but it means production use requires tolerance for frequent updates. The README also mentions a commercial license grant, which is unusual for a GPL-3.0 project. That suggests the project offers a separate commercial license for companies that do not want to comply with GPL obligations. If you plan to modify the code for internal use, the GPL allows that, but if you distribute the modified extension, you must release your changes under the same license. That is a real constraint for a closed-source product.
Alternatives in the Space
The most direct alternative is Immersive Translate, which is also a browser extension for bilingual reading and is listed as a topic on the repository. Immersive Translate focuses on translation quality and supports many providers, but it does not emphasize language learning features like custom AI actions or TTS for study. Another alternative is a simple translation API wrapper that you build yourself, using the same OpenAI or DeepSeek API. That gives you full control over context and cost, but you lose the browser integration and the ready-made UI. The difference in approach is that Read Frog bundles translation with learning-oriented features, while Immersive Translate is primarily a translation utility. If you only need to read foreign articles quickly, Immersive Translate might be simpler. If you want to analyze sentences, compare translations, and build custom AI prompts, Read Frog's learning-first design is closer to your need.
Maintenance, Licensing, and the Path Forward
The repository has a clear maintenance signal: recent releases are frequent, with three versions pushed within a week in September 2026. That indicates an active maintainer and a responsive project. The license is GPL-3.0, which means the code is free to use, modify, and distribute, but any distributed derivative must also be GPL-3.0. The README mentions a commercial license grant, which likely allows companies to use the code under different terms for a fee. That is common for open-source projects that want to fund development. For a user, the practical upgrade cost is low: you install the extension from the store and it updates automatically. For a developer, the cost is higher because you need to track the WXT framework and the project's evolving codebase. The project's homepage and tutorial suggest a growing ecosystem, but the README does not document a stable API or a plugin system. So if you plan to build on top of it, expect to read the source code rather than rely on public interfaces.
Editorial conclusion
Language learners who read foreign-language articles, watch subtitled video, or want sentence-level analysis in the browser should consider Read Frog. It is not the right tool if you need a simple, no-config translation tool or if you want to avoid sending page content to third-party AI APIs. Before adopting it, verify which of the 20+ providers your region can access, check the privacy policy for data handling, and confirm that the GPL-3.0 license fits your use if you plan to modify or redistribute the code. The project is under active development, so expect frequent updates and potential breaking changes.
Community notes