Privacy notice

Last updated: July 26, 2026

OnlyTranslate is a free, open-source browser translation extension. This notice explains what information is stored in your browser, when text is sent to a third-party translation service, and how you can manage that data.

No OnlyTranslate account required

OnlyTranslate does not provide a project-operated account system and does not require sign-in or a subscription. The project does not collect usage analytics, browsing history, translation history, or imported ebooks through the extension.

Data stored in your browser

The following data is stored in your current browser profile:

• translation service and interface settings;
• translation results and video subtitle cache;
• imported EPUB files;
• ebook library, reading progress, and location bookmarks;
• third-party service parameters you choose to configure.

Uninstalling the extension, clearing extension data, or removing a book may delete the corresponding local data. OnlyTranslate does not currently provide cloud sync or remote backup.

Online translation services

When you select Microsoft Translator, Google Translate, DeepL, OpenAI, DeepSeek, Gemini, Claude, or another online endpoint, the webpage text, subtitles, or ebook chapter text being translated is sent to that provider.

Those requests are governed by the selected provider’s privacy policy, account rules, and data-processing terms. OnlyTranslate does not manage the provider’s accounts, quotas, billing, or data-retention policies.

When supported by the current browser and language pair, Chrome built-in translation can process text locally. Availability depends on the Chrome version, local model state, and language pair.

API keys and service configuration

API keys and service settings you enter are stored in browser extension storage and are used to send requests to the selected service. The OnlyTranslate project does not receive or host these credentials.

Do not save private API keys on a public device. When available, use the provider’s security controls to limit key permissions and spending.

EPUB data

Imported EPUB files, library information, reading progress, and bookmarks remain in the current browser and are not uploaded to the OnlyTranslate project. When translation begins, chapter text that needs translation is sent to the provider you selected.

The first version of the ebook reader supports local DRM-free EPUB files only.

Cache

Translation results and video subtitles may be cached locally to reduce repeated requests and waiting time. You can clear the cache from the More menu in the top-right of the OnlyTranslate popup.

Open source and inspection

OnlyTranslate is open source under GNU GPL v3.0. The source code, release history, and issue tracker are available on GitHub.

The project continues development from FluentRead and retains credit for the original project and its contributors.

Contact and feedback

For questions about this notice, data flow, or a specific feature, contact the maintainers through GitHub Issues.