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Critical CSS

(critical-css-extractor.kigo.studio)
234 points stevenpotts | 1 comments | 06 May 25 03:13 UTC | HN request time: 0.217s | source
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oneeyedpigeon ◴[06 May 25 09:05 UTC] No.43903048[source]▶
Feels like premature optimisation to me. Are there really cases where the CSS is so complex or the page loads so many resources that this effort is worthwhile? Maybe with the most complex web apps, I guess, but for almost all cases, I would have thought writing clean CSS, HTML, and JavaScript would render this unnecessary or even counterproductive.
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1. bawolff ◴[06 May 25 18:28 UTC] No.43908178[source]▶
> Are there really cases where the CSS is so complex or the page loads so many resources that this effort is worthwhile?

On the contrary, the more complex the css is or the more resources loaded, the less this would be worthwhile.

The thing i think they are trying to optimize is latency due to RTT. When you first request the html file, the browser needs to read it before knowing the next thing to request. This requires a round trip to the server, which has latency (pesky speed of light). The larger your (critical) css, the more expensive this optimisation is so the less likely it is a net benefit.