CSS Performance: What Slows a Page, and Critical CSS

See why a stylesheet holds up the first paint, find unused CSS with the Coverage panel, animate transform instead of layout, skip off-screen work with content-visibility, inline the critical CSS, and measure the result with Lighthouse.

Updated

Cheat sheet: CSS Performance: What Slows a Page, and Critical CSS
Category
CSS
Level
Freelancer
Tags
Compositing, content-visibility, Critical CSS, CSS, Reflow, Repaint, web-development, will-change