Use cloud backup and restore on supported devices

Data backup on Wear OS 4 is similar to data backup for mobile apps, and it follows similar rules for automatically backing up user data. This document explains how you can add support for backup and restore in your Wear OS app.

On devices that support backup and run Wear OS 4 or higher, users can back up their data to the cloud in order to transfer data off that device, and they can restore data from the cloud to transfer data onto a new Wear OS device. For example, users can perform backup and restore on Google Pixel Watch.

Simulate cloud transfer using local storage

To test the backup and restore flow using simulated cloud storage, complete these steps:

In your app, enable backup and follow the steps outlined at Control backup on Android 12 or higher. For Wear OS, you don't need to specify the additional set of backup rules to support devices that target API level 29 or lower.

Note: If you implement a custom BackupAgent, you should avoid calling the Data Layer inside your backup agent's methods because it may not work correctly if called there.
Connect your device that's running Wear OS 4 or higher to your development machine using a Wi-Fi connection.
Follow the steps in the guide to test cloud backup and restore.

Automatic backup rules

On Wear OS, the conditions required to back up data automatically differ slightly from those on mobile devices. In order for a Wear OS device to automatically back up data, each of the following conditions must be true:

The device is charging.
The device is connected to a Wi-Fi network. This is required even if the device is LTE-enabled.
The device is signed into a Google Account.
At least 24 hours have elapsed since the last backup.

Unlike other devices, wearables running Wear OS aren't required to be idle before backups occur automatically.

In addition, the system automatically backs up any tiles, complications, watch faces, and watch face user styles associated with your Wear OS app.

Backup storage and size limit

Similar to mobile backup and restore, backup data is stored in a private folder in the user's Google Drive account, limited to 25 MB per app. If you have both a mobile app and a Wear OS app, the backups are stored separately, and the two apps don't contribute to each other's size limit.

Any data in the DataStore -- Files > DataStore -- is backed up by default unless you explicitly exclude the corresponding files and directories.