Biblibud
Biblibud Privacy Policy
Effective November 8, 2026
Biblibud is made by Happy Heart Software LLC.
What stays on your device
Your library, the books’ text, where you are in each book, your settings, the companion’s summaries of the stories so far and your conversations with it are stored on this device (in your browser, or in the app). They’re never stored in an account, and we don’t receive or keep copies. Clearing the site’s data, or uninstalling the app, deletes them. Your sign-in, if you sign in, is stored here too. Book lists you’ve looked at (a library’s shelves and genres, not your searches) are kept here for up to a week, so they show again quickly.
Where books come from
Biblibud asks the libraries themselves for books: Project Gutenberg and Unglue.it for ebooks, LibriVox and the Project Gutenberg Open Audiobook Collection for audiobooks, and the Internet Archive, which hosts both kinds of recordings, the Open Audiobook Collection’s catalog and cover art. Some Unglue.it ebooks download from their publisher’s own website. They see your device’s IP address and what you search for, open or play, as any website would.
On the website, requests to LibriVox and Unglue.it, and book downloads, go through Happy Heart Software’s CORS proxy (cors.happyheartsoftware.com), because those servers don’t let other websites read them directly. The proxy passes the request on without cookies or sign-ins and doesn’t keep it, beyond Cloudflare’s standard logs of the request. The Android app asks the libraries directly.
The companion and Happy Heart Plus
The companion is part of Biblibud Plus, from Happy Heart Plus (plus.happyheartsoftware.com), which handles your Plus, buying and AI requests under its own privacy policy. On the website you sign in with your Happy Heart Software account, on accounts.happyheartsoftware.com, under its own privacy policy. Biblibud receives your account ID and email address (to show who’s signed in) and a sign-in token, which it sends to Plus with each question.
In the Android app, Biblibud Plus is bought through Google Play, and signing in is optional. Biblibud sends Plus the purchase token Google Play gives it, so Plus can check the purchase with Google. If you’re not signed in, Biblibud keeps that token on your device and sends it to Plus with each question instead of a sign-in (the Android Auto assistant does the same). If you sign in later, Biblibud asks Plus to move the purchase onto your account, so you can use it on the website too. Google Play handles the payment under Google’s privacy policy; Biblibud never sees your payment details.
Only when you ask a question, Biblibud sends Plus the book’s title and author, how far you are (a percentage and the chapter or track), your question, your last few questions and answers about the book, and, depending on the mode you chose:
- Spoiler-free: up to about 50,000 characters of the book’s text just before your position, and a summary of the story before that. The first time a summary is needed, Biblibud also sends Plus the earlier text a passage at a time (about 60,000 characters each), with the summary so far, to write it; the summary is then kept on your device.
- General: up to about 20,000 characters of the text before your position, and the summary if there is one.
- General + web: the same as General, and articles Biblibud looked up on Wikipedia. To find them, Biblibud sends your question and the book’s title and author to Wikipedia.
The companion isn’t available for books whose license doesn’t allow use in a paid service (such as Creative Commons NonCommercial licenses, or no stated license), so nothing from those books is sent to Plus.
The books are in the public domain or shared freely by their authors and publishers; what’s personal is your question and how far you are. Plus gets an answer from an AI model and returns it to you, without keeping what you sent or got back.
The Android app and the car
Biblibud’s Android app has this site built in and sends the same requests as the website. Audiobooks play in the app’s own player, which keeps where you are so Android Auto can show and play your audiobooks. Android Auto can also list and search LibriVox and the Open Audiobook Collection: your phone sends the words you search for (typed or spoken) straight to LibriVox and the Internet Archive, as the app does, and a book you play there is added to your library on the phone. For an audiobook whose text the app hasn’t downloaded yet (one you first play in the car), your phone downloads the text from Project Gutenberg itself, as the app would, so Ask can answer about it; it’s kept on your phone like the app’s copy, and Project Gutenberg sees your IP address and which book. Signing in opens in your phone’s browser and comes back to the app; signing out removes the sign-in from the app.
In Android Auto, pressing Ask pauses the book and listens for your question with your phone’s speech recognition (usually Google’s, under Google’s privacy policy); this needs the microphone permission, which you can give in Biblibud’s settings, and the microphone is used only after you press Ask. Your question, as text, goes to Plus the same way as from the app (in spoiler-free or general mode, without Wikipedia), and the answer is read aloud by your phone’s text to speech. Questions asked in the car are kept on your phone and added to the book’s conversation in the app.
What we don’t do
No analytics, advertising, tracking or cookies in Biblibud. Fonts and all of Biblibud’s own files load from its own site, or come built into the Android app.