Performance
What is Speed Index?
Speed Index measures how quickly visible content of a page is progressively displayed.
Speed Index measures how quickly page content becomes visually complete.
Targets
- ●Good: < 3.4 seconds
- ●Needs improvement: 3.4-5.8 seconds
- ●Poor: > 5.8 seconds
SEO Impact
A high Speed Index indicates a page that loads visually slowly.
Related Terms
What are Core Web Vitals?
Core Web Vitals are 3 Google metrics measuring the speed, responsiveness, and visual stability of a web page.
What is CLS (Cumulative Layout Shift)?
CLS measures a page's visual stability. A poor CLS means elements move around during loading.
What is LCP (Largest Contentful Paint)?
LCP measures the loading time of the largest visible element on a page. Target: under 2.5 seconds.
What is Page Loading Speed?
Loading speed measures the time needed to fully display a web page. It's a Google ranking factor.
What is Lazy Loading?
Lazy loading is a technique that delays loading images and videos until they're visible on screen.
What is Google Lighthouse?
Lighthouse is a Google tool that audits a web page's performance, accessibility, SEO, and best practices.