Definition
Also written: LCP
Largest Contentful Paint measures when the largest visible element in the viewport finishes rendering — usually a hero image, a video poster or a large text block. Google’s threshold for "good" is 2.5 seconds at the 75th percentile of real visits.
It decomposes into four phases: time to first byte, resource load delay, resource load time, and render delay. Diagnosing which phase dominates matters, because the fixes are unrelated.
Render delay is the most commonly misdiagnosed. A large render-delay share means the element is not painting, which compressing the image further will not address.
The usual error
Where this goes wrong in practice
Compressing the hero image when the load phase is already fast. If the bytes arrive quickly and the paint is still late, the problem is elsewhere.
Related terms
Core Web Vitals
Core Web Vitals are Google’s three user-experience metrics: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability). They are a confirmed ranking signal, and independent analysis indicates they act as a tie-breaker among comparable pages rather than a primary driver.
DefinitionSearch engine optimization (SEO)
Search engine optimization is the practice of making a site easier for search engines to crawl, index, understand and rank, so that pages appear for queries the business can actually serve. It covers technical access, information architecture, content quality, internal linking, authority signals and the measurement that tells you which of those moved.
DefinitionSearch experience optimization (SXO)
Search experience optimization joins ranking work to what happens after the click — page experience, clarity, task completion and conversion. It is the most stable term in the acronym cluster because it describes a genuine scope difference rather than a new surface, and it predates the generative-AI wave.
Definition