The Watch Face Format (WFF) was unveiled at I/O 2023 and is now mandatory for new watches launching with Wear OS 5. Developed in collaboration with Samsung, this XML format eliminates embedded code in watch faces, offering enhanced battery performance and optimization. With Wear OS 5 exclusively supporting WFF on the Galaxy Watch 7, Google emphasizes the importance of meeting performance and quality standards for watch faces. Existing watch faces can still be used on devices running Wear OS 2 or later, but compatibility may be limited when transitioning to a new watch. The latest version of WFF, introduced at I/O 2024, includes new complication styles like goal progress and weighted elements, as well as easier access to weather information. By early 2025, all new watch faces on Google Play must adhere to the Watch Face Format.