Core Web Vitals

Core Web Vitals are the three metrics Google uses to score how a page feels to a real visitor: Largest Contentful Paint (how fast the main content loads), Interaction to Next Paint (how fast the page reacts when you click), and Cumulative Layout Shift (whether things jump around while you read). They're measured from real Chrome users, not lab tests, and they feed into Google's ranking systems.

What are the three Core Web Vitals and their thresholds?

Each vital covers one dimension of experience, with a public "good / needs improvement / poor" threshold:

A page passes Core Web Vitals when all three are "good" — and the grade comes from the 75th percentile of real visits. If a quarter of your visitors have a slow experience, you fail, no matter how fast it feels on your MacBook.

INP is the newest of the three: it replaced First Input Delay (FID) in March 2024, and it's the one animation-heavy marketing sites most often fail — a topic we've covered in depth in our motion metrics breakdown.

Field data vs. lab data — which number is real?

The number that counts comes from the Chrome User Experience Report (CrUX) — anonymized measurements from actual Chrome visitors, reported in Search Console's Core Web Vitals report and PageSpeed Insights ("Discover what your real users are experiencing"). Lab tools like Lighthouse simulate a visit on throttled hardware; they're great for debugging but they are not what Google ranks with.

The practical trap: a site can score 95 in Lighthouse and still fail Core Web Vitals in the field, because real users arrive on mid-range Android phones over hotel Wi-Fi. Always fix the field number, and use lab runs to find out why it's bad.

Why do Core Web Vitals matter for B2B sites?

Two reasons, one obvious and one underrated. The obvious: they're a ranking signal — a tie-breaker rather than a dominant factor, but B2B keywords are exactly where results are competitive enough for tie-breakers to matter.

The underrated: the same slowness that fails LCP loses buyers before the page ever gets a chance to persuade. A B2B visit is often a skeptical, mid-task click from a comparison search — a multi-second wait or a layout jump under the cursor reads as sloppiness. This is why performance is a first-class part of how we build marketing sites in Next.js, not a post-launch cleanup task.

FAQ

Are Core Web Vitals a Google ranking factor?

Yes — they're part of Google's page experience signals, functioning as a tie-breaker among relevant results rather than a primary factor. Great vitals won't rank thin content, but between two comparable pages, the faster and more stable one has the edge — and failing badly can hold otherwise strong pages back.

Where do I check my Core Web Vitals?

Search Console's Core Web Vitals report shows field data for your whole site grouped by URL pattern, and PageSpeed Insights shows it per page (the "Discover what your real users are experiencing" section). Both draw from CrUX, which needs a minimum amount of traffic — very low-traffic pages may show no field data at all.

What's the fastest way to fix failing Core Web Vitals?

Fix them in order of impact: LCP first (usually image size, server response time, or render-blocking resources), then CLS (reserve space for images, embeds, and fonts), then INP (break up long JavaScript tasks and keep animations off the interaction path). Each vital has its own playbook — see the individual entries for LCP, CLS, and INP.