What version of WebKitGTK? (Check About Web -> Troubleshooting -> Debugging Information). This is a little similar to bug #238327, except that one is resolved. Does this happen randomly? If you can find any way to make it happen reliably, that would probably help.

Thanks for your quick reply. WebKitGTK 2.42.1 GStreamer 1.22.6 The problem seems to happen randomly but frequently. I'll see if I can identify any way to make it happen more reliably. The bug you mentioned doesn't seem to affect me--the scrollbar works as expected with no jumpiness.

This happens to me fairly frequently. I found that I can get this to happen often on the New York Times front page. Some context I can add: 1. This only seems to happen when I scroll with the trackpad. Keyboard scrolling hasn't had this issue. 2. It seems to occur only while I'm "holding the scroll" on the trackpad. In other words, I'm scrolling slowly and continuously for a period of time as I'm reading text. 3. I can confirm that when I'm scrolling down, it will jump to the top of the page, and when I'm scrolling up, it will jump to the bottom of the page.

All three of those situations occur with me too--thanks for clarifying the issue. It happens for me on The Guardian's website (British newspaper), Reddit, Slashdot.

(In reply to Michael Catanzaro from comment #1) > This is a little similar to bug #238327, except that one is resolved. Does > this happen randomly? If you can find any way to make it happen reliably, > that would probably help. This one also sounds suspiciously similar to bug #249912, except that one is specific to keyboard scrolling....

I've now seen this behavior in NewsFlash, another WebKitGTK application.

This issue is still present for me in Gnome 45.5 with WebKitGTK 2.44.0 GStreamer 1.22.9. Sadly it prevents me from using Web as my default browser.

Hey, this is still a major issue!! I think I understand what is going on here. It happens on multi-touch touchpads specifically with two-finger scrolling. I am running into this a lot in any WebKitGTK application. I'm on Wayland, GNOME 48. It happens in all directions, not just snapping to the top. Sometimes, you get "teleported" to the top, right, or left completely. Interestingly, I run into this the most when I am very, very slowly scrolling. It seems to happen most often when your fingers move a very small amount and you lift your fingers from the touchpad, I think always when you lift your fingers from the touchpad. I think at very small movements, the acceleration gets set to like, an infinite amount or something, in whatever direction. I say this because it always scrolls exactly to the furthest possible point in the given direction (often the opposite direction) within 1 frame. One thing that would help is probably to clamp the maximum scroll velocity at something high but humanly possible. But more likely, it seems like if there is a very tiny scroll that occurs within a very small number of frames, just before the scroll is released, it averages the velocity as something ludicrously high and then obviously momentum scrolling takes over right after. So, my theory is that this is a bug in the momentum scrolling logic where very tiny changes in a small number of frames leads to a massive velocity. The reverse scrolling may be due to a buffer overflow of some sort, too? Like, maybe the velocity gets set so high that the number actually loops back around past the positive numbers and into the negative numbers? Like, exceeding the 32 or 64-bit integer limit? Just a theory though. I'm experiencing this on the very latest WebKitGTK nightly builds, but have had this issue for as long as I can remember, I just never reported it because I assumed it was a hardware issue? I have this issue on all my laptops actually, as well as my Bluetooth Apple "Magic Trackpad" on my desktop.

And yes, this is EXTREMELY common and very easy to trigger. Easily reproduce-able, just spend an hour reading articles, scrolling slowly on a laptop in Wayland. Please fix! This may be the most annoying bug ever!