Safari now works very similarly to other major browsers when it comes to viewing web content on an iPhone or Mac, following a year-long concerted effort to make the online experience similar across the industry.
As people who grew up with Internet Explorer and Netscape can attest, there can be a big difference between what one browser displays and what another displays. Thanks to efforts between several browser manufacturers, including Apple, web navigation tools now work much more predictably.
As explained in Friday’s WebKit blog post , Interop 2025 was the fourth year browser developers have worked to improve browser interoperability. A group of Apple, Bocoup, Google, Igalia, Microsoft, and Mozilla identified areas where interoperability is important to web developers and then focused on working on those features.
While this is aimed at web developers, the result also has an impact on the end-user experience. With more interoperable browsers, the results of your web code should be predictably identical no matter what browser you use to view it.
For the 2025 cycle, the group has selected 19 focus areas and 5 research areas. This included CSS, JavaScript, web APIs and performance in general.
The WebKit team asked for areas of focus that would require a lot of “engineering investment” from WebKit, the post claims. It was on the belief that his suggestions would have the greatest impact on web developers.
A big improvement
To see how each browser improved, the group selected a set of tests to check the functionality of each area and compared them at the beginning of the project and at the end.
At the beginning of the year, only 29% of selected tests passed in all browsers. In the end, it achieved a success score of 97% in Chrome, Edge, Firefox and Safari.
As for the experimental versions of the browsers, they all achieved a 99% test success rate. This means that changes in future browser software updates will make full versions of the browser compatible for interoperability.
As for the WebKit team’s own work, Safari saw the biggest jump of any browser for the year, from 43% to 99%.
The team said there are three meaningful areas of focus for 2025. Anchor placement allows developers to position popups, labels, and menus relative to other elements using CSS without having to use JavaScript positioning libraries.
View transitions of the same document refer to smooth animated transitions between user interface states that are handled natively in the browser. Support actually shipped in Fall 2024 in Safari 18.0 and Safari 18.2.
Finally, the Navigation API is a replacement for the previous system that dealt with navigation controls in single-page applications. This was shipped as part of Safari 26.2.
While the 2025 effort has ended, Interop 2026 is already underway. The call for proposals went out in September 2025 and the WebKit team is involved again.