Guides on #Core Web Vitals, hand-picked for performance, sustainability and SEO improvements.
Cumulative Layout Shift (CLS) is a measure of how much your webpage's content unexpectedly moves around as it loads. Imagine you're about to tap a button, but just as your finger touches the screen, an ad loads above it, pushing the button down and causing you to tap the ad instead.
Ever clicked on a link and stared at a blank white screen, wondering if the page is broken? That initial wait is what First Contentful Paint is all about.
You've clicked on a webpage. The header and some text load, but you're still waiting for that main banner image or the headline to appear before the page feels truly "loaded." That moment when the most important piece of content finally shows up is what Largest Contentful Paint is all about.