[CharlesW]

> Safari works amazingly for small websites, but for websites with infinite scrolling like Tumblr and Twitter, it becomes unbearably slow after the first hundred or so posts.

That's absolutely not true, even if the web developer implements this in the Dumbest Possible Way. Please point me to an example page and prove me wrong.

[Raymonf]

Sure, if you've got a tumblr.com account just start scrolling on your dashboard and have fun.

You'll be able to see it take seconds to render at a time. This is true on an M1 Mac, as it is true on an A15 iPhone and M1 iPad.

[CharlesW]

> Sure, if you've got a tumblr.com account just start scrolling on your dashboard and have fun.

I scrolled through 300+ stories (or whatever they're called on Tumblr) and it still hasn't slowed at all. Not sure what you're seeing.

[Raymonf]

I just made a brand new account to try it.

On M1 Max with Safari 15.5, it took me about 40 seconds of fast scrolling to get it to start stuttering occasionally. Then, another 30 seconds to get it to start blanking out for a second at a time. And finally, another 30 seconds to get it to start taking seconds to render. I won't give the number of posts before it started lagging because I don't know the exact number.

On my phone (iPhone 13 Pro Max, albeit on the iOS 16 beta), it takes Safari about 15 seconds of scrolling before the scrolling drops to around 40fps from what looked close to 120fps. Then, another 20 seconds to start seeing things rendering halfway before jumping around and then rendering the correct post. This isn't necessarily a fair comparison due to the usage of beta software, but even on an M1 on production OS software it doesn't seem to be much better. Chrome 102 on macOS handles the exact thing that I did without any problem at all.

It's especially bad when you have a lot of videos on your dashboard. If you only have image posts, it might take a bit longer to start stuttering.

This has been the case for years, so it's nothing new. I remember this being a problem almost a decade ago, on an 4th generation iPad with the A6X SoC. Things have improved since then for sure, but those it's probably mostly hardware improvements that's helping.

I'll accept blaming Twitter's horrible performance on its use of React Native Web, but not Tumblr.

[dylan604]

I have to give you credit for going this far into proving whatever we're trying to prove. However, who the hell in the real world infinite scroll this much? Some people do things that would make any QA team more valuable, and you're starting to sound like someone I'd love to have on any QA team I'd work along side.

This really sounds like one of those issues a dedicated person finds where the devs look at it and say no reasonable user would ever do this. The issue if not closed as "won't fix" gets deprioritized so low that it never gets looked at again. Even as a dev, I'd not have the patience to recreate the problem. It's just such an outside edge case from expected behavior/usage that I don't even know what to say in response.

[Raymonf]

That's about 5 minutes of "normal" scrolling on Tumblr and Twitter.

I don't think you're in the target audience of Tumblr, which is fine.

[dylan604]

You're correct. Any website that has so much worthless content that it all gets scrolled passed that quickly without catching my attention to read further is not going to a site I visit regularly after that initial visit.

I honestly worry for people that do. There's something sad to me about people that do.

[jldugger]

I'd say about half of the grafana dashboards i build trigger safari's "this page is using too much memory" popups.

[dylan604]

And what does the assumed digging into the memory usage find?

Is it a memory leak in Safari? Is it a framework issue? You've started us down the path to a thing, but then you didn't finish telling us the thing.

[jldugger]

I'm not debugging safari bullshit when chrome and firefox function fine.