GLOSSARY TERM
What is Speed Index?
Definition
A Lighthouse metric that captures how quickly the visible content of a page is populated, measured as the average time at which visible parts are displayed.
Why it Matters for AI Search
Speed Index correlates with perceived load speed better than any single milestone metric. A page can have a great LCP but a bad Speed Index if everything except the largest element loads slowly.
Related Terms
LCP (Largest Contentful Paint)FCP (First Contentful Paint)TTI (Time to Interactive)Lazy LoadingAVIFChatGPT Search
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