[null,null,["最后更新时间 (UTC):2025-07-27。"],[],[],null,["# Explore features in Wear OS 4\n\nWear OS 4 introduces several features to help enhance your Wear OS app\nexperience. Before you add these features to your app, [prepare your app](/training/wearables/versions/4/test) for\ncompatibility with Wear OS 4.\n\nWatch Face Format\n-----------------\n\nA watch face is the first thing that a user sees when they take a look at their\nwatch, making it the most frequently used surface of Wear OS. Users rely on\nwatch faces to customize their watch to suit their style and meet their needs.\n\nCreated in partnership with Samsung, the [Watch Face Format](/training/wearables/wff) is a declarative\nXML format to configure the appearance and behavior of watch faces. This means\nthat there is no executable code involved in creating a watch face, and there is\nno code embedded in your watch face APK.\n\nThe Wear OS platform takes care of the logic needed to render the watch face so\nyou can focus on your creative ideas, rather than code optimizations or battery\nperformance.\n\nWatch faces that are built using the Watch Face Format require less maintenance\nand fewer updates than the ones built using the Jetpack Watch Face libraries.\nFor example, you don't need to update your watch face to benefit from\nimprovements in performance or battery consumption, or to get the latest bug\nfixes.\n\nThe Watch Face Format is supported on all devices that run Wear OS 4 or higher.\n\nTiles\n-----\n\n[Tiles 1.2](/jetpack/androidx/releases/wear-tiles#version_12_2) introduces support for platform data bindings. This means\nthat---if your tile uses platform data sources such as heart rate, step count, or\ntime---your tile is updated once per second.\n\nThe new version of tiles also adds support for [animations](/training/wearables/tiles/animations). You can use\ntween animations to create smooth transitions on changes to part of your layout,\nand transition animations can animate new or disappearing elements from the\ntile.\n\nSplash screens\n--------------\n\nStarting in Wear OS 4, the system always [applies the default splash screen](/about/versions/12/features/splash-screen)\non both cold and warm app starts. This experience works automatically for all\napps running on Wear OS 4 or higher.\n\nThe default splash screen icon uses the same specifications as\n[adaptive icons](/guide/practices/ui_guidelines/icon_design_adaptive). For visual consistency, use an adaptive icon for your\nlauncher icon.\n\nIf your app implements a custom splash screen or uses a launcher theme, migrate\nyour app to use the [`SplashScreen`](/reference/kotlin/androidx/core/splashscreen/SplashScreen) library, available in Jetpack. That way,\nyour splash screen can appear correctly on all Wear OS versions. For full\ninstructions, see the [implementation guide](/training/wearables/apps/splash-screen).\n\nTransfer Wear OS data to a new mobile device\n--------------------------------------------\n\nStarting in Wear OS 4, users can request that the system transfer their Wear OS\ndata from one mobile device to another. When the system connects the user's Wear\nOS device to the new mobile device, any data that's stored in the wearable\nnetwork is transferred to this new mobile device. The system then disconnects\nthe Wear OS device from the old mobile device.\n\nAs long as your mobile app is already installed and [properly configured](/training/wearables/data/transfer-to-new-mobile) on\nthe new mobile device, your mobile app receives a callback containing the\nWear OS data that was associated with the old mobile device.\n\nRecommended for you\n-------------------\n\n- Note: link text is displayed when JavaScript is off\n- [Migrate your splash screen implementation to Android 12 and later](/develop/ui/views/launch/splash-screen/migrate)\n- [Splash screens](/develop/ui/views/launch/splash-screen)\n- [App startup time](/topic/performance/vitals/launch-time)"]]