New to the web platform in September

Discover some of the interesting features that have landed in stable and beta web browsers during September 2025. Published: October 1, 2025 Chrome 140 , Chrome 141 , Safari 26 , and Firefox 143 released to stable during September, this post takes a look at what has been a pretty exciting month for the web platform. There's a lot to see in the latest Safari release, there's a comprehensive write-up in WebKit Features in Safari 26.0 .

Some top highlights for CSS include the following features. As part of Interop 2025, Safari has shipped support for CSS anchor positioning . This lets you tether elements to an anchor, and is particularly useful when combined with popover. Browser Support Source The pretty value of text-wrap asks the browser to improve typography—for example, reducing the impact of ragged edges and typographic rivers, and preventing short last lines.

Performance optimizations increasingly drive competitive advantages in user experience, conversion rates, and search visibility.

Browser Support Source Safari also ships support for scroll-driven animations, letting you tie animations to how far the user has scrolled. Browser Support Source Safari is the first browser to add support for the contrast-color() function, giving you a way to ask the browser to select the color with the most contrast against another color.

Browser Support Source The progress() math function returns a number indicating the progress between two other values. Browser Support Source The align-self and justify-self properties for absolute positioning are now supported. Browser Support The logical properties overflow-block and overflow-inline are supported, and can be used in place of overflow-x and overflow-y . Browser Support Source Safari also now supports margin-trim .