[null,null,["最后更新时间 (UTC):2025-07-27。"],[],[],null,["# Use cloud backup and restore on supported devices\n\nData backup on Wear OS 4 is similar to [data backup](/guide/topics/data/backup) for mobile apps, and it\nfollows [similar rules for automatically backing up user data](#automatic-backup). This document\nexplains how you can add support for backup and restore in your Wear OS app.\n\nOn devices that support backup and run Wear OS 4 or higher, users can back up\ntheir data to the cloud in order to transfer data off that device, and they can\nrestore data from the cloud to transfer data onto a new Wear OS device. For\nexample, users can [perform backup and restore on Google Pixel Watch](https://support.google.com/googlepixelwatch/answer/13579590#zippy=%2Cpair-your-phone-with-a-new-pixel-watch).\n| **Note:** Cloud backup and restore, where the user restores data to a new Wear OS device, is different from [transferring Wear OS data to a new mobile device](/training/wearables/data/transfer-to-new-mobile), where the user connects their existing Wear OS device to a new mobile device.\n\nSimulate cloud transfer using local storage\n-------------------------------------------\n\nTo test the backup and restore flow using simulated cloud storage, complete\nthese steps:\n\n1. In your app, [enable backup](/guide/topics/data/autobackup#EnablingAutoBackup) and follow the steps outlined\n at [Control backup on Android 12 or higher](/guide/topics/data/autobackup#include-exclude-android-12). For Wear OS, you don't need to\n specify the [additional set of backup rules](/guide/topics/data/autobackup#include-exclude-android-11) to support devices that target\n API level 29 or lower.\n\n | **Note:** If you implement a custom [`BackupAgent`](/guide/topics/data/autobackup#ImplementingBackupAgent), you should avoid calling the [Data Layer](/training/wearables/data/data-layer) inside your backup agent's methods because it may not work correctly if called there.\n2. Connect your device that's running Wear OS 4 or higher to your development\n machine using a [Wi-Fi connection](/training/wearables/get-started/debugging#wifi-debugging).\n\n3. Follow the steps in the guide to [test cloud backup and restore](/guide/topics/data/testingbackup#TestingBackup).\n\nAutomatic backup rules\n----------------------\n\nOn Wear OS, the conditions required to [back up data automatically](/guide/topics/data/autobackup) differ\nslightly from those on mobile devices. In order for a Wear OS device to\nautomatically back up data, each of the following conditions must be true:\n\n- The device is charging.\n- The device is connected to a Wi-Fi network. This is required even if the device is LTE-enabled.\n- The device is signed into a Google Account.\n- At least 24 hours have elapsed since the last backup.\n\nUnlike other devices, wearables running Wear OS aren't required to be idle\nbefore backups occur automatically.\n\nIn addition, the system automatically backs up any [tiles](/training/wearables/tiles),\n[complications](/training/wearables/tiles/complications), [watch faces](/training/wearables/watch-faces), and [watch face user styles](/reference/kotlin/androidx/wear/watchface/style/UserStyle)\nassociated with your Wear OS app.\n\nBackup storage and size limit\n-----------------------------\n\nSimilar to mobile backup and restore, backup data is [stored in a private\nfolder](/guide/topics/data/autobackup#BackupLocation) in the user's Google Drive account, limited to 25 MB per app.\nIf you have both a mobile app and a Wear OS app, the backups are stored\nseparately, and the two apps don't contribute to each other's size limit.\n\nAny data in the `DataStore` -- **Files \\\u003e DataStore** -- is backed up by default\nunless you explicitly exclude the corresponding files and directories.\n| **Caution:** Partial backups aren't supported. If the total size of the files and directories within a Wear OS backup is greater than 25 MB, then no data from the Wear OS app is backed up.\n\nRecommended for you\n-------------------\n\n- Note: link text is displayed when JavaScript is off\n- [Save simple data with SharedPreferences](/training/data-storage/shared-preferences)\n- [DataStore (Kotlin Multiplatform)](/kotlin/multiplatform/datastore)\n- [Working with Proto DataStore](/codelabs/android-proto-datastore)"]]