Learn what Radicale offers for self-hosted calendars and contacts: CalDAV/CardDAV support, features, pricing (free/open source), and FAQs.
Radicale is a lightweight, open-source CalDAV and CardDAV server that lets individuals and small teams self-host their own calendars, to-do lists, journals, and contact lists instead of relying on a third-party cloud provider. Development began at the end of 2008, and the project has been maintained continuously since by creator Guillaume Ayoub and the Kozea collective based in Lyon, France.
The project's guiding principle is simplicity: it aims to work out of the box with little to no configuration, storing data as plain files on disk rather than requiring a database server. This makes Radicale easy to install, back up, and reason about, even for users without deep sysadmin experience.
Radicale supports the core CalDAV and CardDAV standards for syncing events, to-dos, journal entries, and vCard-based contacts, and it works with a broad range of client apps including Thunderbird, Apple Calendar and Contacts, DAVx5 on Android, and GNOME Evolution. Data is stored in a simple file-system folder structure, which simplifies backups, version control, and migration.
Authentication is pluggable, with built-in support for htpasswd, PAM, and LDAP backends, plus a configurable rights system for fine-grained authorization. Radicale can terminate TLS connections directly, and its plugin architecture allows further extension of authentication, storage, and web interface behavior.
Radicale is entirely free and open source under the GPLv3 license. There is no commercial company selling licenses, subscriptions, or hosted plans; users install and run it on their own server, VPS, NAS, or home lab hardware.
The only ongoing cost is the infrastructure used to host it and, optionally, a domain name and TLS certificate if not using Radicale's built-in TLS support. Support comes from the project's documentation, GitHub issues, and community channels rather than a paid help desk.
Yes. Radicale is free and open source under the GPLv3 license with no paid tiers, subscriptions, or usage limits.
Radicale implements CalDAV for calendars, to-dos, and journal entries, and CardDAV for contacts, accessible over standard HTTP/HTTPS.
Radicale stores all calendar and contact data directly on the file system in a simple folder structure, rather than requiring a separate database server.
Radicale is compatible with most standard CalDAV and CardDAV clients, including Thunderbird, Apple Calendar and Contacts, DAVx5 on Android, and GNOME Evolution.
Radicale was created by French developer Guillaume Ayoub, with development beginning at the end of 2008, and is maintained by the Kozea collective based in Lyon, France.
Yes. It supports pluggable authentication backends such as htpasswd, PAM, and LDAP, along with a configurable rights system for authorization.
No. Radicale can run standalone and even terminate TLS connections directly, though many deployments still place it behind nginx or Apache for added hardening.
Yes. The project maintainers note that some users run Radicale in production for demanding workloads, including medical scheduling systems handling thousands of requests per day.