Privacy

Updated October 30, 2026

Bookfy has no account of its own and shows no ads. Your books, highlights, bookmarks and progress stay on your device. Only what is listed below leaves the device: ad measurement, which you can turn off, and what each feature needs, only when you use it.

Sync

If you turn on sync, the app stores in your own cloud (Google Drive, OneDrive or Dropbox, whichever you choose) your progress, highlights, notes, bookmarks and shelves and, on Wi-Fi, a copy of your books. It asks each service for the smallest permission: on Google Drive the app only sees the files it created itself; on OneDrive and Dropbox, only its own folder (Apps/Bookfy). Nothing goes to a Bookfy server. Turning sync off does not delete what is in your cloud.

Bookfy's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

AI features

When you ask for a summary or an explanation, or ask a question, the app sends the book's title and author, the chapter name, the chapter text up to where you are (never what comes after), the passage or question, the last turns of the conversation, the device language and a random number generated in the app to count the daily limit. The request goes through a Bookfy server (Cloudflare) to Anthropic, which writes the answer. The Bookfy server does not keep the text; the counters are cleared the next day. Anthropic handles the data under its own policy.

App check

So that only Bookfy installed from Google Play can use the AI and send problem reports, each request carries an attestation from Google (Play Integrity) about the app and the device. The Bookfy server asks Google whether the attestation is valid and keeps only the result for 3 days: whether the app came from Google Play, whether your account got it there and whether the device passed the check. None of this identifies you. Google handles the attestation under its own policy. If you subscribe to Premium, AI requests also carry the subscription receipt that Google Play gives the app: the server asks Google whether it is active and doesn’t keep the receipt.

Subscription

Payment happens in Google Play: Bookfy never sees your card details. The app only asks Google Play whether your account has the subscription.

Problem reports

When you report a problem in the app, it sends the text you wrote, the Bookfy version, the device model, the Android version, the language and, if you provide it, your email. The report goes through the Bookfy server (Cloudflare), which doesn't store it, and reaches support by email. It is used only to reply and fix the problem.

Dictionary

When you look up a word, it is sent to Wiktionary (Wikimedia), which returns the definition.

Translation

Translation runs on the device, with Google's on-device translator (ML Kit): the passage does not leave your phone. The first time you use a language, its model is downloaded from Google. "Open in Google Translate" sends the passage to Google's app or website.

Free books and guided reading

The books in the free catalog, their covers and the model for guided comic reading are downloaded from the Bookfy server (Cloudflare). Only the request for the file goes out, with your device’s internet address; nothing from your library. The model runs on the device: the pages of your comics never leave it.

Voice

Read-aloud uses Android's voices. Some voices on the device work over the internet, depending on the installed speech engine.

Ad measurement

To learn which ads bring people who install and subscribe, Bookfy from Google Play sends a few events to Google (Google Analytics for Firebase) and Meta (Facebook): the install, opens and time spent in the app, the first book opened (only its format), the Premium feature you tapped, and the start of a purchase, a free trial and a subscription (with the price). Along with them go the device model, the Android version, the language and, if Android allows it, the advertising ID; Google infers the approximate region from the internet address. Nothing from your books, highlights or notes leaves. In the European Economic Area, the United Kingdom and Switzerland, measurement only turns on if you allow it; in other countries it is on. To turn it off: You, Terms & licenses, Privacy. You can delete the advertising ID in Android settings. Google and Meta handle this data under their own policies.

Your rights

You can delete everything the app keeps: removing a book deletes the file, its cover and its AI conversation; highlights and bookmarks can be removed one by one; uninstalling the app deletes everything. Sync files stay in your cloud account, where you can delete them. Questions and requests: contact@bytewelllabs.com.

Terms of use

What Bookfy is

A reader for the ebooks, comics and audiobooks you already have. The app does not sell or lend books: it opens the files you choose.

Your files

You are responsible for the files you open in the app. DRM-protected files do not open.

AI features

Summaries, explanations and answers are generated by artificial intelligence and may contain mistakes. There is a daily usage limit.

Bookfy Premium

Some features are part of Bookfy Premium, a subscription billed by Google Play, monthly or yearly. The yearly plan may start with free days: when they end, billing starts automatically unless you cancel before then. The subscription renews automatically each period. Cancel anytime in Google Play, under Payments & subscriptions; you keep access until the end of the paid period. Ending the subscription doesn't delete anything of yours.

No warranty

The app is provided as is. Keep copies of your books and notes: the app stores everything on the device and, if you turn on sync, in your cloud.

Changes

These terms may change with new versions of the app. The version in effect is the one on this page.