Privacy policy

The short version

The calibre-zen app collects nothing. There is no account to create, no analytics, no crash reporting and no advertising. We operate no server that your copy of the app talks to, so there is no data for us to hold, sell or lose.

Your books, metadata, covers and settings live in ordinary files on your own disk. They leave your computer only when you ask them to — by downloading metadata, sending a book to a device, or starting the content server yourself.

This website does count visits, with Google Analytics. The details are below.

What we collect

Nothing. To be specific, calibre-zen contains no sign-in, no unique install identifier, no usage or event tracking, no crash or error reporting, no advertising, and no third-party analytics or marketing SDKs. We receive no information about you, your device or your library.

What stays on your computer

calibre-zen is a library manager, so it reads and writes a good deal of data — all of it locally:

• Your library: book files, metadata, covers, tags, custom columns and conversion output, in the library folder you chose.
• Your settings: preferences, saved searches, column layouts, the interface theme, and plugin configuration, in calibre-zen's own configuration directory. It installs beside calibre and keeps its own state, so neither app writes to the other's.
• Caches: cover thumbnails, search indexes and job history.

Deleting the app's configuration directory removes all of it. Your library folder is yours and is never touched by an uninstall.

When calibre-zen uses the network

calibre-zen is a fork of calibre and inherits calibre's network behaviour unchanged. The fork adds no network activity of its own. Every connection below is either something you started or something you can switch off, and none of it passes through us:

• Update check. On start, the app asks calibre's own server whether a newer version exists. The request carries no identifier for you or your library; that server sees the connecting IP address, as any web server does. Turn it off in Preferences → Behaviour → Notify when a new version is available.
• Metadata and cover downloads. When you run one, the title, author or ISBN being looked up is sent to the metadata sources you have enabled — Google Books, Amazon, Open Library and the rest. Each has its own privacy policy.
• News downloads. A scheduled recipe fetches articles directly from the publisher's own site, using any credentials you gave that recipe.
• Store searches. Searching for books to buy sends your search terms to the stores you selected.
• Content server and wireless devices. These run on your machine and serve your library over your own network, to the devices and accounts you configure. Nothing is relayed through a third party.
• Plugins. Third-party plugins you install can make their own connections and are outside this policy. Plugin installation contacts calibre's plugin index.

This website and the downloads

This site is a set of static files served by Cloudflare. Cloudflare keeps standard request logs, including IP addresses, to deliver and protect the site.

The site uses Google Analytics to count visits. It records the pages you view, where you came from, your browser and device, and your rough location. It also notes when you follow a link to another site or download a file.

It sets cookies named _ga that last one day, so each visitor counts once per day. It doesn't store your IP address. Google signals and ad features are off. The script and its data go through purplecandy.dev first, and Cloudflare passes them on to Google. Google stores this data and keeps it for 2 months. This is the website only. The app itself still sends nothing.

Release downloads are hosted by GitHub, whose own privacy statement applies once you follow a download link.

Email signups

Some free resources on this site ask for an email address before the download, and you can sign up for news by email. Only then do we keep anything: the address, which resource or list it was for, the page you signed up on, and the country Cloudflare reports for the request. We store it in Notion, which processes it for us, and use it only to send what you asked for and the occasional news. We never sell or share it.

Every email has a way to unsubscribe, or you can ask us to delete your address at any time by writing to nadeem@kibibyte.in.

Your data rights

Requests to access, correct, export or delete personal data are a normal part of a privacy policy, so to be explicit: the app gives us none, which leaves nothing for us to produce or erase. Everything the app knows about you is on your own disk, in a format you can open, copy and delete yourself. The website's analytics are counted per day, aren't tied to your name or email, and are deleted after 2 months.

calibre-zen is not directed at children, and the app collects no data from anyone regardless of age.

Changes

If this policy changes, the date at the top of the page changes with it, and anything material is noted in the changelog on the home page. Should calibre-zen ever gain a feature that sends data anywhere new, that feature will be described here and will be something you opt into.

Contact

Questions about this policy go to nadeem@kibibyte.in, or to the issue tracker. calibre-zen is maintained by Nadeem Siddique.