You have 200 books
at home.
You know you lent Les Misérables to someone. But to whom?
You're at the bookshop, a novel catches your eye, and you hesitate: "Do I already have this one?"
And tonight, your neighbour rings the doorbell: "Do you have a good book I could borrow?"
Good question. Maybe you do. Somewhere. On a shelf. Or at someone's place.
BiblioGenius is a free, open source personal library app. It runs on your device, needs no account, and lets you lend your books directly to the people around you. Here is why it exists.
The problem
Today, managing a personal library means a notebook at best, total oblivion at worst.
And the existing apps? Your reading habits, your tastes, your data live on their servers, behind an account. Not at home with you.
If the app shuts down tomorrow, your library vanishes with it.
In practice
Imagine: you've spent three years building your catalogue online. 500 books. Notes, custom shelves, carefully tracked loans.
One morning, the app changes its terms of service. Or worse: it shuts down.
Everything evaporates. Three years of work. Gone.
And even when everything works, you can't truly lend a book to a friend. You can "recommend" a title.
Recommending is not sharing.
It's not the same as handing a book to someone and saying: Here, you'll love this.
The library that truly belongs to you
Scan a barcode. The book appears with its cover, summary, and detailed information.
Organise your reads. Track your loans. Instantly find out who borrowed what.
And above all: your data stays on your phone. No account required. No remote server. No ads.
Your library works even without internet. It's yours, full stop.
What if you change phones? One tap to save everything, one tap to restore. Your books follow you, always.
The moment everything changes
Now, imagine something else.
Your friend Sophie also has BiblioGenius. You scan her QR code. In one second, her library appears on your phone.
No cloud needed. No middleman. No need to be on the same "social network."
It's as if she opened the door to her library and said: Help yourself.
You see she has Dune. You request a loan. She accepts. The app tracks everything: who has the book, since when, and when it should come back.
Peer-to-peer lending. Direct, simple, human. No algorithm deciding. Just two people sharing a passion.
What BiblioGenius gives you
- Instant scanner: add a book in one second, cover and summary included
- Your entire catalogue in your pocket: novels, comics, manga, textbooks, audiobooks
- Loan tracking: no more "I already returned it, I swear"
- Reading statistics: pages read, books finished, badges to unlock
- Offline mode: your library works even without internet
- Free export: retrieve all your data whenever you want
Free and open source. Transparent, ethical, no strings attached.
Why BiblioGenius exists
Because we believe your books belong to you. Not to a company.
Because real sharing is a direct gesture between two people, not a "recommend" button on a platform.
Because a library should be a neighbourhood commons, not an exploited database.
Where BiblioGenius comes from
The idea dates back to 2020. A final project during Harvard's CS50 course, taken online: add, correct and sort books from their ISBN by querying open catalogues.
It was picked up, dropped, picked up again. A mobile app on Symfony, then on Drupal and NativeScript, with barcode scanning. The same obsession every time, and a technical base that never went the distance.
The version you install today dates from November 2025: a Rust core, a Flutter interface, and lending between readers placed at the centre rather than bolted on. On the app stores since August 2026.
Six years, three generations of code. That is also the answer to the question this page asks further up: what becomes of your library if the app disappears? Here the code is public, the export format is documented, and your books are already on your device. Even the worst case leaves them with you.
BiblioGenius in brief
- What it is
- A personal library app: organise your books, track your reading, and lend them directly to the people you trust.
- Since when
- November 2025 in its current form, after a first version in 2020. On the stores since August 2026.
- Licence
- AGPL-3.0. Source code public on Codeberg.
- Platforms
- iOS, Android, macOS, Windows, Linux. Interface in French, English, Spanish and German.
- Price
- Free. No subscription, no in-app purchase, no advertising.
- Your data
- On your device. No mandatory account; the optional account stores only ciphertext the server cannot read. The detail.
- Book data
- Open catalogues: BnF, Inventaire, OpenLibrary. Google Books stays optional, enabled with your own key.
- Who makes it
- Federico Calo, an independent developer, with volunteer contributors. The acknowledgements.
Your books,
simply yours.
Download BiblioGenius. Scan your first book.
And next time your neighbour rings the doorbell to ask "Do you have a good book I could borrow?", you'll know exactly what to answer.