Calibre Online: your calibre library, in the browser
A calibre web app for your ebook library. Read, organise and fix your EPUB, PDF, MOBI and AZW3 books on any device, with nothing to install and nothing uploaded: your library lives in your browser.
An online ebook manager in the spirit of calibre
Calibre Online brings the heart of the beloved calibre desktop program to the web: a real library with covers, series, tags and ratings, a full metadata editor, a built-in ebook reader that remembers your page, and the power tools calibre users expect, reachable from a laptop, a tablet or a phone.
Bring your whole calibre library with you
- Import a calibre folder: point it at the folder holding
metadata.dband everything arrives: books, covers, series, tags, ratings and summaries. - Connect a calibre content server and browse its libraries remotely.
- Restore a full calibre export: the
.calibre-databackup made by “Export all your calibre data” opens here, multi-gigabyte parts included.
Read anywhere
The reader opens EPUB, PDF, MOBI, AZW3, HTML, Markdown and plain text. It saves your last page, keeps modern bookmarks, turns pages with realistic animation and sound, reads aloud, and plays quiet background ambiences while you read. On a phone it feels like a native app, and the iOS app is the same library in your pocket.
Metadata, fixed properly
A full metadata editor with title and author sort forms, series splitting, identifiers with ISBN extraction, and covers you can replace, generate or download. Summaries download in your own language, French included, instead of an English blurb or nothing at all, and search looks inside them: type a filter likeauthor: or ask a question in plain words.
Plugins, sandboxed and honest
A plugin store lists 241 plugins for the calibre desktop program, each on its own page with a direct download, alongside extensions for Calibre Online itself: single Lua files running sandboxed in WebAssembly, where every API call is a permission the user reads before installing. The developer guide documents the whole API.
Made for schools and shared shelves
Our dream is to own a library. If just one school uses this software to digitalize their book library, the project has done its job: teachers and students open a browser and the shelf is there, on every device, at no cost.
Frequently asked questions
- Is Calibre Online free?
- Yes. The app is free to use, and your books stay on your device unless you create an optional account to sync them.
- Can I import my existing calibre library?
- Yes. Choose your calibre library folder (the one holding metadata.db) and Calibre Online reads it in your browser: books, covers, series, tags, ratings and summaries. Nothing is uploaded.
- Which formats can it read?
- EPUB, PDF, MOBI, AZW3, HTML, Markdown and plain text, in a reader that remembers where you stopped.
- Is this the official calibre?
- No. Calibre Online is an independent project made in the spirit of calibre, and is not affiliated with calibre or Kovid Goyal. The desktop calibre lives at calibre-ebook.com.
- Does it work on a phone?
- Yes. The interface adapts to phones and tablets, and an iOS app wraps the same library.