Effective: October 10, 2026
Your books, dictionaries, saved words, reading progress, and reading statistics are stored on your device. Mekuru does not upload them to any server run by Mekuru.
Some features send data to a server only when you set them up and use them:
Mekuru does not require an account or sign-in. Pro purchases are handled by Google Play (Android) or the App Store (iOS). If your settings still point to the remote OCR server used by older versions of Mekuru, the app creates an anonymous Firebase Authentication identity to talk to that server. It is not linked to your name or email.
Mekuru uses Sentry for crash reports. A crash report includes the error and stack trace, the device model, the operating system version, and a randomly generated installation identifier. File paths are removed before a report is sent.
If you send feedback from the app, your message goes to Sentry together with the name and email address you type in the form, if any. They are then linked to that installation identifier, so your feedback can be matched with crash reports from your device.
Mekuru collects usage statistics to understand which features are used and how well they perform. For example: how often the reader, dictionary, OCR, and Anki export are used, how long operations take, rough library size, and whether Mekuru Pro is unlocked. This data is sent to Sentry and to Google Firebase Analytics with general device information and a randomly generated installation identifier. Firebase Analytics also estimates your approximate location (country and region) from your IP address. Mekuru does not use the advertising identifier. Usage statistics never include book titles, file names, page content, or the words you look up.
On-device OCR runs entirely on your device: page images are not uploaded. With remote OCR, page images and OCR requests are sent only to the custom OCR server you configure. Mekuru does not provide or operate an OCR processing server. Any images or request data sent during remote OCR are handled by the server you choose, under that server operator's own policies and retention practices.
Sentence translation runs on your device: Mozilla's Firefox Translations engine or the optional Gemma model on Android, and Apple's Translation framework on iOS. The sentences you translate are not sent to a server.
When you download dictionaries, models, the free-book catalog, or a free book, Mekuru contacts the server that hosts it, such as GitHub, Hugging Face, Mozilla, Aozora Bunko, or Tadoku. Like any web request, these servers see your IP address. Mekuru sends them no personal data.
Mekuru uses Sentry for crash reports, feedback, and usage statistics, and Firebase Analytics for usage statistics. It contacts Google Play billing (Android) or the App Store (iOS) for Pro purchases, and Firebase App Check to protect requests to Mekuru's own services.
Mekuru does not include advertising SDKs and does not track you across other apps or websites. Crash reports, feedback, and usage statistics are used only to improve the app. They are never used for advertising, sold, or shared with data brokers.
Crash reports, feedback, and usage statistics are kept indefinitely. To have yours deleted, follow the steps on the Delete Your Data page.
Questions about this policy or your data: mekuru@matthew.moe.
If this policy is updated, the changes will be reflected on this page.
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