Core Web Vitals

Core Web Vitals are three metrics measured on real visits rather than in a lab. Largest Contentful Paint covers how long the main content takes to appear, Interaction to Next Paint covers how quickly the page responds to input, and Cumulative Layout Shift covers how much the page moves around while it loads.

They are a ranking input, but a small one and a threshold rather than a gradient — being fast does not outrank being relevant, and shaving milliseconds off an already-passing page buys nothing in search. The honest reason to fix them is that the same problems cost conversions on every visit regardless of where the visitor came from.

Because the score comes from field data, it lags. A fix deployed today moves the reported number over the following weeks as the rolling window refills, which is why lab tools are the right feedback loop during the work and field data is the right measure of whether it landed.