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Title: Largest Contentful Paint (LCP)  |  Articles  |  web.dev

Open Graph Title: Largest Contentful Paint (LCP)  |  Articles  |  web.dev

Description: This post introduces the Largest Contentful Paint (LCP) metric and explains how to measure it

Open Graph Description: This post introduces the Largest Contentful Paint (LCP) metric and explains how to measure it

Opengraph URL: https://web.dev/articles/lcp

direct link

Domain: web.dev

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perceived load speedhttps://web.dev/articles/user-centric-performance-metrics#types_of_metrics
usefulhttps://web.dev/articles/user-centric-performance-metrics#defining_metrics%22
loadhttps://developer.mozilla.org/docs/Web/Events/load
DOMContentLoadedhttps://developer.mozilla.org/docs/Web/Events/DOMContentLoaded
First Contentful Paint (FCP)https://web.dev/articles/fcp
First Meaningful Paint (FMP)https://developer.chrome.com/docs/lighthouse/performance/first-meaningful-paint
Speed Index (SI)https://developer.chrome.com/docs/lighthouse/performance/speed-index
W3C Web Performance Working Grouphttps://www.w3.org/webperf/
image, text block, or videohttps://web.dev/articles/lcp#what-elements-are-considered
Time To First Byte (TTFB)https://web.dev/articles/ttfb
Defining the Core Web Vitals metrics thresholdshttps://web.dev/articles/defining-core-web-vitals-thresholds
Largest Contentful Paint APIhttps://wicg.github.io/largest-contentful-paint/
first frame presentation timehttps://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/speed/metrics_changelog/2023_08_lcp.md
first frame presentation timehttps://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/speed/metrics_changelog/2023_08_lcp.md
url()https://developer.mozilla.org/docs/Web/CSS/url()
CSS gradienthttps://developer.mozilla.org/docs/Web/CSS/CSS_Images/Using_CSS_gradients
Block-levelhttps://developer.mozilla.org/docs/Web/HTML/Block-level_elements
First Contentful Paint (FCP)https://web.dev/articles/fcp
overflowhttps://developer.mozilla.org/docs/Web/CSS/overflow
intrinsic sizehttps://developer.mozilla.org/docs/Glossary/Intrinsic_Size
spec termshttps://wicg.github.io/element-timing/#set-of-owned-text-nodes
containing blockhttps://developer.mozilla.org/docs/Web/CSS/Containing_block
PerformanceEntryhttps://developer.mozilla.org/docs/Web/API/PerformanceEntry
PerformanceEntryhttps://developer.mozilla.org/docs/Web/API/PerformanceEntry
font block periodhttps://developer.mozilla.org/docs/Web/CSS/@font-face/font-display#The_font_display_timeline
Timing-Allow-Originhttps://developer.mozilla.org/docs/Web/HTTP/Headers/Timing-Allow-Origin
responseEnd in Resource Timinghttps://developer.mozilla.org/docs/Web/API/PerformanceResourceTiming/responseEnd
resolved in late 2024https://github.com/w3c/paint-timing/issues/104
is available from Chrome 133https://chromestatus.com/feature/5128261284397056
in the labhttps://web.dev/articles/user-centric-performance-metrics#in_the_lab
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Largest Contentful Paint APIhttps://wicg.github.io/largest-contentful-paint/
PerformanceObserverhttps://developer.mozilla.org/docs/Web/API/PerformanceObserver
Differences between the Metric and the APIhttps://web.dev/articles/lcp#differences-metric-api
back/forward cachehttps://web.dev/articles/bfcache#impact_on_core_web_vitals
show as a difference between CrUX and RUMhttps://web.dev/articles/crux-and-rum-differences#iframes
prerendered pageshttps://developer.chrome.com/docs/web-platform/prerender-pages
activationStarthttps://developer.mozilla.org/docs/Web/API/PerformanceNavigationTiming/activationStart
web-vitals JavaScript libraryhttps://github.com/GoogleChrome/web-vitals
the source code for onLCP()https://github.com/GoogleChrome/web-vitals/blob/main/src/onLCP.ts
limitationshttps://github.com/GoogleChrome/web-vitals#limitations
Element Timing APIhttps://wicg.github.io/element-timing/
custom metricshttps://web.dev/articles/custom-metrics#element_timing_api
optimizing LCPhttps://web.dev/articles/optimize-lcp
Lessons learned from performance monitoring in Chromehttps://youtu.be/ctavZT87syI
Annie Sullivanhttps://anniesullie.com/
performance.now()https://perfnow.nl/
Changeloghttps://chromium.googlesource.com/chromium/src/+/main/docs/speed/metrics_changelog/lcp.md
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