[Bug]: Pinch to zoom on mobile is very buggy

[federicocappellotto97]

Attach (recommended) or Link to PDF file

If i open your demo on my iPhone 14 Pro, using Brave browser, pinch to zoom is unusable. Zooming on a point the pdf randomly jumps and the zoom is not smooth, not allowing me to focus on the part i want to zoom on.
This also happens my pdf player using your library.

2025-12-04.17.45.48.mp4

Web browser and its version

Brave

Operating system and its version

iOS 26

PDF.js version

latest

Is the bug present in the latest PDF.js version?

Yes

Is a browser extension

No

Steps to reproduce the problem

1. Open the demo
2. Pinch to zoom

What is the expected behavior?

Smooth zoom on the wanted point

What went wrong?

Zoom is not working good

Link to a viewer

https://mozilla.github.io/pdf.js/web/viewer.html

Additional context

No response

[nicolo-ribaudo]

Does the workaround described in #17571 solve the problem for you?

[federicocappellotto97]

Does the workaround described in #17571 solve the problem for you?

Hi @nicolo-ribaudo :) I tried to clone the repo, and i added this css to web/pdf_viewer.css

.pdfViewer .canvasWrapper,
.pdfViewer .page canvas[zooming] {
  width: inherit !important;
}

But it's still flickering while pinching to zoom, you can see it clearly at the end of the video

compressed-video.mp4