Radicale
What Radicale is
Radicale is a free, GPLv3-licensed CalDAV and CardDAV server for sharing calendars, to-do lists, and contacts. It handles events, to-dos, journal entries, and business cards, with shared calendars and two-way synchronization. Data is stored on a file system in a simple folder structure. Administrators can choose authentication methods, apply authorization policies, and secure connections with TLS; the default server configuration binds to localhost. Connection controls cover parallel connections, file size, failed authentication attempts, and timeouts. Radicale runs on Linux, macOS, Windows, and other UNIX-like systems, including *BSD. Installation options include PyPI, source packages, Linux distribution packages, and Docker images for linux/amd64 and linux/arm64. Listed clients include DAVx⁵, OneCalendar, GNOME Calendar and Contacts, Evolution, KDE PIM applications, Thunderbird, and InfCloud. Plugins can extend authentication, rights management, web, and storage functions. Radicale is a server, so compatible clients provide the working interface.
Who it suits
It suits people or organizations wanting a self-hosted server for multiple calendars and address books. It is also relevant when file-based storage, client choice, and configurable access controls matter.
What it does well
- Free plan with GPLv3 license
- Two-way calendar synchronization
- Supports calendars, tasks, contacts, and journals
- TLS and authorization policies available
- Runs on Linux, macOS, Windows, and *BSD
What to know first
- Provides no interface for working with the server
- Self-hosted deployment is required
- Connection and file-size limits apply
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free and open-source | GPLv3-licensed software · self-hosted CalDAV/CardDAV server | Free |
As radicale.org lists them, read 12 Oct 2026. The maker's own page has the final word.
Verdict
Radicale provides a free, self-hosted way to share calendar, task, and contact data. Its client compatibility, file-based storage, and access controls suit users comfortable managing their own server.
Facts from Radicale's own pages
- Authentication and access
- It offers flexible authentication options and can restrict access through authorization policies. · radicale.org, 12 Oct 2026
- Calendar sync
- two_way · radicale.org, 22 Sept 2026
- Connection limits
- It limits parallel connections, file size, and incorrect authentication attempts, and terminates connections after a timeout. · radicale.org, 12 Oct 2026
- Deployment
- The project provides installation options through PyPI, source packages, Linux distribution packages, and Docker images for linux/amd64 and linux/arm64. · radicale.org, 12 Oct 2026
- Extensibility
- Radicale can be extended with plugins, including authentication, rights management, web, and storage plugins. · radicale.org, 12 Oct 2026
- Free plan
- Yes · radicale.org, 22 Sept 2026
- Integrations
- The project lists tested clients including DAVx⁵, OneCalendar, GNOME Calendar and Contacts, Evolution, KDE PIM applications, Thunderbird, and InfCloud. · radicale.org, 12 Oct 2026
- Mobile apps
- android · radicale.org, 22 Sept 2026
- Product scope
- Radicale describes itself as a server and says it will not provide interfaces for working with the server. · radicale.org, 12 Oct 2026
- Security
- It can secure connections with TLS; its default server configuration binds to localhost. · radicale.org, 12 Oct 2026
- Shared calendars
- Yes · radicale.org, 22 Sept 2026
- Storage
- It stores data on the file system in a simple folder structure. · radicale.org, 12 Oct 2026
- Supported data
- It supports events, to-dos, journal entries, and business cards. · radicale.org, 12 Oct 2026
- Supported operating systems
- The project says Radicale runs on most UNIX-like platforms, including Linux, *BSD, and macOS, as well as Windows. · radicale.org, 12 Oct 2026
- What it does
- Radicale is a CalDAV and CardDAV server for sharing calendars, to-do lists, and contacts. · radicale.org, 12 Oct 2026
- Who it is for
- Radicale describes itself as a lightweight, easy-to-install and easy-to-configure server for storing and manipulating multiple calendars and address books. · radicale.org, 12 Oct 2026
Where Radicale stands on Freedom251
- Calendar apps#75 of 194