What is Radicale used for?

Radicale is a small CalDAV and CardDAV server for sharing calendars, to-do lists and contacts, written in Python and storing data as plain files. It is a good fit for self-hosted calendar and contacts sync, replacing a hosted calendar provider, and sharing calendars within a small team.

Is Radicale open source?

Yes. Radicale is open source under the GPL-3.0 licence. Its source code is on GitHub at Kozea/Radicale and is written mainly in Python.

Yes. Radicale is open source, so the software itself is free to use.

Can I self-host Radicale?

Yes. Radicale can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is Radicale an alternative to?

Radicale is an open-source alternative to Google Calendar, Proton Calendar, Zoho Calendar and Apple Calendar. Other open-source alternatives to Google Calendar include Baïkal, Manage My Damn Life and DAVx⁵.

Is Radicale actively maintained?

Yes. The most recent commit to Radicale was on 1 October 2026, and the latest release is v3.8.1, published on 24 September 2026. The project has 5.1k stars on GitHub.

Radicale: open-source alternative to Google Calendar

About Radicale

Radicale is a lightweight CalDAV and CardDAV server for sharing calendars, to-do lists and contacts. It speaks CalDAV, CardDAV and HTTP, handles events, todos, journal entries and contact cards, and works with many calendar and contact clients.

It is meant to work out of the box without complicated setup. Access can be limited through authentication, connections can be secured with TLS, and all data is kept on the file system in a simple folder structure. Behavior can be extended with plugins, and the project provides documentation, a wiki and a discussion board.

Radicale is written in Python and distributed as free software under GPL-3.0. Because it needs only a file system for storage, it suits individuals, families and small teams who want to host their own calendar and address book instead of depending on a hosted provider.

Key features

CalDAV calendar and to-do sharing
CardDAV contact sharing
Events, todos, journals and contact cards
Authentication and TLS support
File system storage in plain folders
Plugin-based extensibility

Good fit for

→Self-hosted calendar and contacts sync
→Replacing a hosted calendar provider
→Sharing calendars within a small team

Built with: Python
Tags: caldav; carddav; calendar; contacts; self-hosted; python; icalendar; sync

Radicale: questions and answers

What is Radicale used for?: Radicale is a small CalDAV and CardDAV server for sharing calendars, to-do lists and contacts, written in Python and storing data as plain files. It is a good fit for self-hosted calendar and contacts sync, replacing a hosted calendar provider, and sharing calendars within a small team.
Is Radicale open source?: Yes. Radicale is open source under the GPL-3.0 licence. Its source code is on GitHub at Kozea/Radicale and is written mainly in Python.
Is Radicale free?: Yes. Radicale is open source, so the software itself is free to use.
Can I self-host Radicale?: Yes. Radicale can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is Radicale an alternative to?: Radicale is an open-source alternative to Google Calendar, Proton Calendar, Zoho Calendar and Apple Calendar. Other open-source alternatives to Google Calendar include Baïkal, Manage My Damn Life and DAVx⁵.
Is Radicale actively maintained?: Yes. The most recent commit to Radicale was on 1 October 2026, and the latest release is v3.8.1, published on 24 September 2026. The project has 5.1k stars on GitHub.