Nolan LawsonNov 27

"The top-line takeaway is chilling: sites that are explicitly designed as SPAs, and which have intentionally opted in to metrics measurement around soft-navigations are seeing one (1) soft-navigation for every full page load on average."

Amazing research and analysis as always from @slightlyoff https://infrequently.org/2025/11/performance-inequality-gap-2026/

The Performance Inequality Gap, 2026

Embedded in this year's network and device estimates is hopeful news about the trajectory of devices and networks. It has never been easier to deliver pages quickly, but we are not collectively hitting the mark. Indeed, the latest CrUX data shows not even half of origins have passing Core Web Vitals scores for mobile users. Browsers will need to provide stronger incentives. This will be unpopular, but it is clearly necessary.

Alex Russell
Show threadNolan LawsonNov 27

@slightlyoff Frankly I'm skeptical of _all_ claims of SPA superiority:

- Paying for slow initial load is amortized across subsequent soft navs
- Soft navs are faster than hard navs
- Any of this is worth breaking the back button

You can always point to one SPA where it works, but in aggregate it doesn't seem to be working.

Show threadThomas Steiner Nov 28
@nolan Can you point out one SPA where it actually works well indeed? I'm always so frustrated by GitHub, where even on a WiFi network it's often faster to right-click and open in a new tab.
Show threadBen KellyNov 28
@tomayac @nolan What about Gmail?
Show threadThomas Steiner Nov 28
@ben @nolan Gmail is indeed a good example, and so is WhatsApp Web. I really wonder why GitHub's is so bad.
Show threadNolan LawsonNov 28
@tomayac @ben Gmail is exactly what I was going to say FWIW. Google Maps and Netflix work too.
Show threadppk 🇪🇺Nov 28

@nolan @tomayac @ben A while ago there was a theory that people would only voluntarily install apps from entities they interacted with on a near-daily basis, such as their banks. Everyone and their dog kept pushing their apps, though, and I'm not sure how consumers feel about apps nowadays.

This SPA discussion is the exact counterpart of that app theory in the web space. Companies force their poorly thought-out SPAs on all consumers .. and I'm not sure how they feel about websites nowadays.

Show threadNolan LawsonNov 28

@ppk @tomayac @ben One thing I find ironic about this is that the whole SPA craze was driven by app-envy, and yet I don't think anyone would argue that the average SPA has eclipsed the average native app yet.

Part of it I think is that web developers didn't adjust their other habits – storing all data in memory instead of disk, doing all work on the main thread instead of web/service workers, not testing on real mobile devices, etc.

Show threadNolan Lawson
@ppk @tomayac @ben BTW Rich Harris' talk from PerfNow this year made one of the best cases I've seen for the SPA side. (Wish I had been there!) I think if I could paraphrase his argument, it's that SPAs have a high "ceiling," so we shouldn't dismiss them for the low "floor" we tend to see in practice. I'm pessimistic, but I'm glad folks like him are still pushing on this.
Nov 28 at 4:53pmWeb
Show threadppk 🇪🇺Nov 28
@nolan @tomayac @ben Wouldn't the same go for an app? Very useful if you interact often, but a bit of a dud if you just need it once?
Show threadNolan LawsonNov 29
@ppk @tomayac @ben Unless you think the upfront costs aren't really that high (e.g. for a Svelte app). I don't want to put words in his mouth, though.