Discover some of the interesting features that have landed in stable and beta web browsers during December 2025.

Google’s web.dev is a resource for web developers, offering guidance, tips, and best practices for building websites and web applications. The site covers a range of topics including performance, accessibility, security, and development tools, all aimed at helping developers create user experiences. With a focus on the latest web technologies and standards, web.dev provides tutorials, coding labs, and articles authored by industry experts, making it a destination for developers looking to stay current in the evolving web landscape.

web.dev

December 2025 brings significant updates across Chrome 143, Firefox 146, and Safari 26.2. Notable additions include CSS @scope at-rule becoming Baseline, contrast-color() function for accessible color selection, and text-decoration-inset property. Safari 26.2 enables LCP and INP metrics measurement across all major browsers, adds CHIPS cookie partitioning, and supports hidden="until-found" and command/commandfor attributes. The scrollend event and scrollbar-color property also reach Baseline status. Beta releases preview CSS anchor positioning in Firefox 147 and the Temporal API in Chrome 144.

New to the web platform in December