DAVx⁵ is the standard way to sync calendars, contacts, and tasks on Android against an open CalDAV/CardDAV server, integrating natively with the built-in calendar and contacts apps. It is not a server itself, you connect it to a DAV backend such as Nextcloud, Baïkal, mailbox.org, or Fastmail, making it the missing link that frees Android from Google's calendar and contact sync. It also supports WebDAV file access and one-way iCalendar subscriptions. The app is fully open source under the GPLv3 and free on F-Droid, while the same build on Google Play carries a small one-time fee to support the developers. Development is very active, with v4.5.14 released in mid-2026 by bitfire in Austria.
DAVx⁵
Open-source CalDAV/CardDAV sync client for Android.
davx5.comFreeOpen SourceAndroidAustria
PricingFree and open source on F-Droid; the identical app is a small one-time paid purchase on Google Play to fund development.
Strengths
- Native Android sync for calendars, contacts, and tasks
- Works with any standard CalDAV/CardDAV server
- Free and open source via F-Droid
- Actively maintained with frequent releases
Considerations
- Requires a separate CalDAV/CardDAV server to be useful
- Android only
- Protection is transport-level (TLS), not end-to-end encryption
- The Google Play build costs money, though F-Droid is free
Listed inCalendars
