Core Web Vitals and INP: the speed scores that affect search

Largest Contentful Paint measures how fast the main content loads, with a target under 2.5 seconds. Interaction to Next Paint measures how quickly the page responds to a tap or click, with a target under 200 milliseconds. Cumulative Layout Shift measures visual stability, with a target under 0.1.

Google judges these at the seventy fifth percentile of real visits over a rolling twenty eight day window, so they reflect how the page performs for most people, not in a lab.

In 2024 a metric called Interaction to Next Paint replaced the older responsiveness measure, and it has stayed the standard through 2026. It captures lag across a whole visit, not just the first interaction, which is a fairer picture of how a page feels.

Heavy scripts and bloated pages are the usual cause of poor INP. Trimming unused code and keeping interactions light is the practical fix.

Passing Core Web Vitals is a modest ranking signal, but the bigger payoff is conversion. Faster, more stable pages keep more visitors and turn more of them into customers. A slow page loses business whether or not it ranks.

On sites we build, we treat these scores as part of the spec, not an afterthought, because the same work that pleases Google also keeps real customers from leaving.