Bug 295624 – iOS 26 has slower rendering on dendionigi.com than iOS 18

• Component: Layout and Rendering
• Status: RESOLVED DUPLICATE

Created attachment 475822 [details]
Video which demonstrates the iOS26 Safari's bug

I am testing stuff on a website, and it worked well on any mobile browser till iOS18.

Now that I am testing iOS26, even with the latest BETA (3) everything works smoothly on any other mobile browser but Safari.
Safari iOS26 crashes and lag, while the same web screens, side by side, with another iPhone, same model but running iOS18, don't give any issue.

Previously I had also the bug for status-bar flickering and lagging, which now has been patched, but instead the popovers and pages bugs seem still there.

SITUATION:

I have persistent popovers and ajax smooth navigation, and both are rendering with bugs, lagging and fouc while views/pages change.

Example: If I have an element which must stay on its place and its width is 100vw: while pages change: it blinks, shrinks, flicker and jumps on rendering, instead it simply must stay as is..

Animations and page transitions work smoothly on Chrome mobile (latest iOS 26 beta 3) , so it's something just related to Safari and webkit.

I did open an Apple Feedback FB18328720, but seems no one caring.

You can see here a video of the issue: https://www.youtube.com/shorts/rY3oxUwDd7w

And here you can test live: opening the bottom sheet, you can see bottom links, which should be persistent across page views without any crazy lag or shrinks, which is visible only on latest iOS26 mobile Safari browser: https://www.youtube.com/shorts/rY3oxUwDd7w

It's a rendering engine issue.

[Simon Fraser (smfr)]

<rdar://154168198>

[Alexey Proskuryakov]

*** This bug has been marked as a duplicate of bug 295625 ***