Note from 28 June 2021
Rhetorical WebPerf question: is it better to have a low or stable Cumulative Layout Shift? 😅
Rhetorical WebPerf question: is it better to have a low or stable Cumulative Layout Shift? 😅
Jeremy Wagner
New field insights for debugging INP
Interaction to Next Paint (INP) is a Core Web Vital that measures how responsive a page is to interactions. Due to INP's scope, it can be difficult…
I love (some) boring #SpeedCurve graphs… 😅
Apparently, an image whose part above the fold is indeed the largest, but of which only a small part can be seen, can be considered an LCP element, even if another image has a larger part visible... 😭
You can see this for my photography site in this WebPageTest result:
https://www.webpagetest.org/vitals.php?test=230606_BiDcN4_4NJ&run=3&cached=0#lcp
Watch Out for Layout Shifts with ‘ch’ Units
In our case, we were using ch
units to define our page layout. This meant that our post content was equal to 50ch
units (or the width of fifty…
Limiting the image density on mobile devices drasticaly improves performance, with no visual loss, so we did it!
I still wish it was much easier than dealing with <picture>
and x
descriptors for fluid images… 😞
With a <img maxdensity="2.5" …>
attribute for example!
If you agree, comment:
https://github.com/whatwg/html/issues/4421