Last updated: October 5, 2026
BookFit opens and shows your e-books entirely on your device. Your books are never uploaded, transmitted, or shared. We collect no personal data.
All reading happens locally in your browser. When you open a book, BookFit keeps a copy of the file, its title, author and cover, and your place in it, in your browser's own storage (IndexedDB) on this device, so your library is there next time. Nothing about your books — not the file, not the title, not how far you've read — is sent anywhere. Removing a book from the list deletes that copy; your original file is never changed. Your reading settings (text size, theme, layout) are kept in your browser's local storage. BookFit works offline.
An e-book file can contain links, pictures from other websites, or scripts. Before a chapter is shown, BookFit removes scripts and anything that would load from another website, and the page is locked so that nothing in a book can contact a server. If you click a web link inside a book, it opens in a new tab, as any link would.
The BookFit browser extension collects nothing: no analytics, no telemetry, no cookies, no account, no ads. The extension requests only the "storage" permission, used to remember your settings and (if you buy Pro) your license key — kept in your browser's local storage. It requests no access to the pages you visit. If we ever add privacy-friendly, cookieless analytics to the website version, they will never include your books or any personal data, and this policy will be updated first.
Purchases are processed by Lemon Squeezy (their privacy policy applies to checkout). Keys bought through Lemon Squeezy are checked once, with Lemon Squeezy, when you enter them; that request contains only the key. Older bundle keys (they start with FIT1) are checked on your device, with no request. After that, the key is kept only in your browser's local storage and isn't checked again.
BookFit shows books with foliate-js by John Factotum (MIT), which includes zip.js by Gildas Lormeau (BSD-3-Clause). BookFit's own code is MIT-licensed.