Google CWV at launch — brand-new sites usually have NO CrUX field data (popularity/traffic threshold); Mueller confirms the signal "is not used" without sufficient field data

Claim: Core Web Vitals are assessed from real Chrome user data (CrUX), at the 75th percentile over a rolling 28-day window, with all three metrics (LCP, INP, CLS) required to pass.

CrUX requires a popularity/traffic threshold for a site to have field data at all. A brand-new site usually has no CrUX field data, and Mueller has confirmed that without sufficient field data the signal "is not used" — neither helping nor hurting.

Implication: at launch, CWV is not a gate AND not an advantage. Get into the "good" range with lab tools (PageSpeed Insights, Lighthouse) so the site is ready when field data accrues, then largely leave it alone.

Source: Google Search Central CWV documentation; CrUX documentation; John Mueller on-record.

Confidence: Verified. Grade A.

Caveat: This is the launch-specific correction that most "CWV optimisation at launch" pitches ignore — there is literally nothing in the field data to optimise.