Post

Robin Marx
@programmingart.bsky.social

These differences can be quite stark, such as in the screenshot below, where 1 simple Web page is loaded completely differently in the 3 main browsers... This means it's difficult to build pages that perform consistently well across them, and features like fetchpriority and preload don't help much 🤡

Robin Marx
@programmingart.bsky.social

Probably also of interest to @tunetheweb.com (thanks again for the photoshoot Barry!), @csswizardry.com, @twnsnd.com, @yoav.ws, and @imkev.dev, who's one of the few people who actually researched this topic as well (imkev.dev/fetchpriorit...)

imkev.devFetch Priority and optimizing LCPFetch Priority is used to indicate to the browser the relative priority of a resource. I take a deep dive into how you can improve your Largest Contentful Paint by using fetchpriority.
Bramus
@bram.us

Great talk, loved it and learned a few things! Three questions: 22:05 – The third style sheet in Safari does not trigger tight mode. Is this because it takes too long to load (at +5s), or because Safari imposes a limit on how many stylesheets can be in tight mode?

Robin Marx
@programmingart.bsky.social

Here, I think Safari just falls back to normal tight mode logic: it's still in tight mode, but there's just 1 high-prio resource in flight (the 3rd CSS that's slow to load), so it starts loading low-prio stuff, but only 1 at a time. I don't think this is a special case due to stylesheets.

Bramus
@bram.us

24:07 – My guess would be that the preload scanner in Safari (or similar thing they most likely have) finds the script tags and then reprioritizes stuff? Could you try adding more images before the 2 scripts? 33:53 – Can we hire you to make some balloons at kids parties?

Robin Marx
@programmingart.bsky.social

1. Yeah, could be, didn't really dig super-deep into this one yet because it felt so inconsistent. 2. this was actually SO MUCH HARDER THAN IT LOOKS. I was practicing in my hotel room all night before... luckily I think @guaca.bsky.social has some skills here, so you can book us as a double act ;)