Total Browser Processing Time
Time To First Layout
Layout Rendering Time
CSS Processing Time
CSS Calculations
Javascript Execution Time
Javascript Event Listeners
CSS Processing Time
Target Less than 0.4 seconds
How long does the browser spend processing page CSS?
A longer time spent processing CSS should be considered blocking time within the browser.
CSS can be 1) included in your initial page HTML payload, 2) downloaded as a file.css, or 3) injected by third-party apps.
The more CSS that is evaluated on a page, the slower it will perform.
Large amounts of CSS on a page can also negatively affect re-rendering of the page when elements are resized, scrolls occur, or javascript code injects elements into the DOM to be rendered after initial page load.
