Alongside today’s system updates, Apple has released Safari 26.3, with a mix of under-the-hood improvements and at least one major usability upgrade for Vision Pro users. Here are the details.
Better fullscreen handling on visionOS, efficiency improvements for all
With Safari 26.3, Vision Pro users on visionOS 26.3 will see Safari automatically dim their surroundings when a video enters fullscreen, a change Apple says helps “put the focus on the content.”
In addition, Safari 26.3 introduces support for Zstandard (Zstd), an open, real-time compression algorithm developed by Meta that essentially compresses text-based web assets before they’re delivered to browsers and then decompresses them quickly on-device.
Apple says that “Zstandard decompresses quickly, reducing the workload on users’ devices. It also compresses fast enough to do on-the-fly, whereas Brotli is typically pre-compressed during your build process.”
Apple notes that users need to be running Safari 26.3 on iOS 26.3, iPadOS 26.3, visionOS 26.3, and macOS Tahoe 26.3 for Zstd support to work.
If you’re a developer, you might be happy to know that Safati 26.3’s Navigation API now “exposes a AbortSignal on NavigateEvent which triggers when the navigation is aborted,” which Apple says is a “reliable way to cancel ongoing work when a navigation gets interrupted.”
Finally, WebKit for Safari 26.3 contains the following developer-facing bug fixes and improvements:
CSS Fixed a style resolution loop that occurred when a position-try box was inside a display: none ancestor. (163691885)
box was inside a ancestor. (163691885) Fixed an issue where anchor-positioned elements repeatedly transitioning from display: block to display: none cause position jumps during animation. (163862003)
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