Largest Contentful Paint (LCP)
LCP measures how long until the largest visible element — usually a hero image or headline — has rendered. Google considers 2.5 seconds or less good, measured at the 75th percentile of real visits.
Poor LCP is nearly always one of four things: a slow server response, a render-blocking stylesheet or script, an unoptimised hero image, or a font that delays text. Diagnosing which takes minutes; the fix is usually straightforward once identified.
The most common own goal is a hero image lazy-loaded. Lazy loading is right for images below the fold and actively harmful for the one element LCP measures.
Why it matters
The single most impactful performance metric to fix, because it's what a visitor experiences as "this site is slow" in the first moments.
Related terms
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