DAVx⁵

DAVx⁵ syncs calendars, contacts and tasks between your phone and a server that speaks CalDAV and CardDAV, the open standards that Nextcloud, many hosting providers and mail services use. It doesn’t come with an app of its own for your events or contacts: it puts them into Android’s own storage, so the calendar, contacts and task apps you already use show them. Its description: “Use it with your own server or with a trusted hoster to keep your contacts, events and tasks under your control.”

It is made by bitfire web engineering in Bad Vöslau, Austria, and has been around since 2013, first under the name DAVdroid; the package name still says so. Version 4.5.21 came out on 15 October 2026. The official site is davx5.com.

What it syncs

• Calendars and tasks over CalDAV, and contacts over CardDAV, in both directions. Tasks and journals go to a separate task app; DAVx⁵ itself describes the three it works with: jtx Board “Supports sync of Tasks, Journals and Notes”, Tasks.org “Some features are not supported”, and OpenTasks “Doesn’t seem to be developed anymore – not recommended.”
• WebDAV files appear in Android’s file picker and file managers, streamed from the server. The FAQ: “DAVx⁵ is not a files sync app … you can’t setup a folder-sync.”
• Webcal subscriptions, read-only calendar feeds, are handed to the same developers’ separate app, ICSx⁵.

For calendars from DAVx⁵ to appear in Google’s Calendar app, the FAQ says you have to turn on the DAVx⁵ accounts in that app’s settings first.

Signing in

You can log in with a server address and user name, with an e-mail address, which DAVx⁵ uses to find the server, or with advanced settings. Three providers have their own login: Nextcloud, through Nextcloud’s login flow in your browser, and Google and Fastmail, through their sign-in pages.

Defaults worth knowing

From the code of this version:

• Sync every 4 hours; events older than 90 days aren’t synced; after you log in, no calendars or address books are selected until you pick them.
• Wi-Fi only is off, and there is no restriction to particular Wi-Fi networks until you set one.
• Push is on, but only does something with servers that offer WebDAV-Push. The app then uses a UnifiedPush app if you have one; if you don’t and Google Play services is installed, it uses Google’s Firebase Cloud Messaging instead. The Use Push setting turns this off. The privacy policy doesn’t mention the Google route.
• On first start, a series of pages asks for permissions, for an exemption from battery optimization, and for a donation. On Android 17 the permissions include local network access, which DAVx⁵ needs to sync with a server on your own network; without it, the main screen shows a warning. A card on the main screen about the Keep Android Open campaign stays until you tap Dismiss forever.

What goes online

• Your servers, for setup and every sync. To find a server from an e-mail address, it looks up DNS records; on Android 7 to 9 it adds Quad9’s public resolver as a fallback.
• Google’s or Fastmail’s sign-in servers, only if you use those logins, and Firebase Cloud Messaging in the push case above.
• Links to davx5.com, when you tap them, carry the app version, the Android version and the screen you came from, which the code calls “query parameters for anonymized usage statistics”.

Apart from that, this edition doesn’t contact its developers: the privacy policy says “No personal data are ever transferred to our servers”, and we found no analytics, crash reporting or update check. When the app crashes, it shows the debug information on the phone.

Version 4.5.21 fixes a bug from 4.5.20 that stopped a calendar’s sync when the server listed an event without an ETag; such entries are now skipped and logged.

About this file

• This is the developers’ own build of 4.5.21, the “ose” edition, byte for byte the APK on the project’s GitHub release, which IzzyOnDroid distributes unchanged. Its certificate matches the fingerprint published on davx5.com.
• The Google Play edition is paid and built from a separate, non-public version of the code. There are also two other apps: Managed DAVx⁵ for organisations, which is a subscription, and the free DAVx⁵ Select, for servers of partner providers.
• The 17.7 MB file runs on Android 7.0 and later and declares 26 permissions: calendars, contacts, and the task apps above; internet, network state, and on Android 17 local network access; Wi-Fi state and location for the Wi-Fi name; Android’s sync settings; notifications; starting at boot and background work for scheduled syncs; and the battery-optimization request.
• DAVx⁵ is licensed under the GPL-3.0. Some of its illustrations come from unDraw, under unDraw’s own free licence, and it shows the Google, Firebase and Mastodon logos next to those features. DAVx⁵ is a registered trademark of bitfire web engineering.
• The screenshots are the project’s own store images, from about mid-2024; the login screen in them doesn’t have the Fastmail option yet.

CPU types in this build: arm64-v8a (64-bit ARM, almost every phone since 2017); armeabi-v7a (32-bit ARM, older and budget phones); x86 (32-bit Intel, emulators); x86_64 (64-bit Intel, emulators and Chromebooks).

Versions currently kept in the IzzyOnDroid repository. We host and check only the newest one. Full changelog.