Privacy

Last updated: November 4, 2026

Foldbook is published by Believemy. This page covers the Foldbook app for Android, iPhone and iPad, Foldbook Server and this website. In short: without an account, Foldbook collects nothing. The account is optional; if you create one, it only keeps what it needs to bring your setup and reading back on your other devices.

What we don't collect

Foldbook has no analytics tool, no ads, and sends no crash reports to Believemy. We don't look at what you read: the book names and paths your account keeps are only used to give you your progress back. This website has no cookies and no visitor statistics.

What stays on your device

Your libraries, progress, bookmarks, notes, drawings, covers and the books you download for offline reading are stored in the app, on your device. Your server passwords are kept in the iOS keychain, or in Android’s encrypted storage. Deleting the app erases what is on the device; the account stays until you delete it.

Your servers

Foldbook connects directly to the sources you add (NAS, WebDAV, iCloud Drive, OPDS catalog) to read your files. Without an account, it writes your progress to a .folio-progression.json file on your own NAS. Your files never go through Believemy.

Your Foldbook account

If you create an account, we keep your email address (or the one Sign in with Apple provides, which can hide your real one), when the account was created, when you last opened Foldbook, your system (iOS or Android, and its version) and the app version. This makes the account work and tells us how many people use Foldbook. It isn't used for ads or to track you across apps, and it's never sold or shared.

What your account syncs

The name, address and username of your NAS and servers, your libraries (the folder and what is in it), your settings, your progress in each book (its path, name, size and the page you reached) and your annotations: bookmarks, notes, highlights and drawings. Your books never leave your servers.

Your NAS passwords

By default they stay in your device's keychain. If you turn on “NAS passwords” in Settings › Account, they're also kept in your account, encrypted, so your other devices connect without you typing them again. Turning it off erases them from your account.

Shared library

If you install Foldbook Server on your NAS, your account keeps the name you give it, when it last connected, the people you invite (their account and the name you give them) and what each of them may see. Foldbook Server reads your files on your NAS and only sends them to the people you invited. When they read away from your home, pages go through our relay, relay.foldbook.app, which passes them on without keeping or looking at them. Invited people keep their own account, with their own progress and notes.

Where your data lives

The account is hosted by Supabase, on servers in Paris. The relay runs on an OVH server in France. Email sign-in codes are sent by SendGrid. For Foldbook+, RevenueCat receives your subscription status from the App Store or Google Play (product, dates, renewal), tied to your account ID; Apple or Google handles the payment and we never see your card. Data is kept for as long as the account exists.

Third-party services

To show a series page, Foldbook sends the series name to Wikipedia and, for manga, to AniList. If you play a trailer, it streams from YouTube. Signing in with Apple or Google goes through those services. They receive your IP address as with any web page, and apply their own privacy policies.

Deleting your account

In Foldbook, Settings › Account › Delete my account: everything your account keeps is erased right away, including your Foldbook Servers and invitations. You can also write to hello@believemy.com to access, correct or erase your data.

Children

Accounts are for people aged 15 and over, or with a parent's consent. A parent can invite their child to their shared library and hide titles.

Contact us

Believemy, EURL, 229 rue Saint-Honoré, 75001 Paris, France, RCS Paris 950 731 331. For any question: hello@believemy.com. You can also contact the CNIL (cnil.fr), the French data protection authority.

Changes

If Foldbook ever collected any other data, this page would be updated before the app version concerned, and the date above would change.