Search engines
Core Web Vitals
Core Web Vitals are three measurements Google uses to describe a page's loading experience: Largest Contentful Paint (how long until the main content appears), Interaction to Next Paint (how quickly the page responds to a tap or click), and Cumulative Layout Shift (how much the layout moves while loading). They are part of Google's page experience signals and are measured from real visits.
The measurement that counts for search is field data, collected from actual Chrome users, not the score a testing tool produces in a lab. A page can score well in a lab test on a fast connection and still fail in the field where visitors are on phones and slower networks.
Real estate sites usually fail on the largest image and on layout shift. A full-width hero photo that has not been resized delays the main content, and a listing widget that loads late pushes the page around under the reader's thumb.
These signals are tie-breakers rather than primary ranking factors. A fast page with weak content does not outrank a slow page with the answer, but among comparable pages, the experience matters, and it matters more for whether visitors stay.
Why it matters
Most agent-site visits happen on a phone, where a slow-loading page loses the visitor before the content ever appears.
Related terms
Related reading
Sources
Every claim on this page that could be checked against a primary source is linked below. Where something is not publicly documented by a vendor, the page says so rather than filling the gap with an estimate.
- Understanding page experience in Google Search results (Google Search Central)
Last reviewed 2026-09-04. All Saige glossary terms.