Largest Contentful Paint
55 established claims - 17 refused by the grounding gate
Verdict
Largest Contentful Paint reports the render time of the largest image, text block, or video visible in the viewport relative to when the user first navigated to the page. As documented by web.dev and Google Search Central, a good LCP is 2.5 seconds or less and a poor threshold is 4 seconds, measured at the 75th percentile of page loads segmented across mobile and desktop; LCP includes unload time, connection setup, redirect, and other Time To First Byte delays, which can create field and lab differences. In Chrome, measurement stops at the first tap, scroll, or keypress; the metric became stable in Chrome 79, and later releases changed it: Chrome 83 fixed subframe inputs and scrolls, Chrome 88 excluded full viewport images and stopped recording after input in out-of-process iframes, Chrome 96 used the full page viewport when ignoring images, Chrome 112 began ignoring images below 0.05 bits of image data per displayed pixel, Chrome 116 made videos and animated images eligible in UKM and CrUX reporting but not PerformanceObserver observations in JavaScript, and Chrome 130 made transparent text with no visible decorations ineligible. A slightly coarsened render time has been available from Chrome 133 without Timing-Allow-Origin.
Written from the 55 established claims below, then checked against them. How that works.
Documented position27
What the operator of the system says in its own documentation.
Google's Search Central documentation on Core Web Vitals states that site owners should strive to have Largest Contentful Paint occur within the first 2.5 seconds of the page starting to load.
1 quote from 1 source
Largest Contentful Paint (LCP): Measures loading performance. To provide a good user experience, strive to have LCP occur within the first 2.5 seconds of the page starting to load.
web.dev's Largest Contentful Paint article states that LCP reports the render time of the largest image, text block, or video visible in the viewport, relative to when the user first navigated to the page.
1 quote from 1 source
LCP reports the render time of the largest image, text block, or video visible in the viewport, relative to when the user first navigated to the page.
web.dev states that a good Largest Contentful Paint value is 2.5 seconds or less.
1 quote from 1 source
A good LCP value is 2.5 seconds or less.
web.dev states that the…
- threshold to measure Largest Contentful Paint against is the 75th percentile of page loads.
- Largest Contentful Paint measurement threshold is segmented across mobile and desktop devices.
1 quote from 1 source
To ensure you're hitting this target for most of your users, a good threshold to measure is the 75th percentile of page loads, segmented across mobile and desktop devices.
- web.dev states that <video> elements are considered for Largest Contentful Paint.
- web.dev states that for a <video> element, the Largest Contentful Paint time is the earlier of the poster image load time and the first frame presentation time.
1 quote from 1 source
<video> elements (the poster image load time or first frame presentation time for videos is used—whichever is earlier)
web.dev states that <image> elements inside an <svg> element are among the element types considered for Largest Contentful Paint.
2 quotes from 1 source
the types of elements considered for Largest Contentful Paint are:
<image> elements inside an <svg> element
web.dev states that block-level elements containing text nodes or other inline-level text element children are among the element types considered for Largest Contentful Paint.
2 quotes from 1 source
the types of elements considered for Largest Contentful Paint are:
Block-level elements containing text nodes or other inline-level text element children.
web.dev states that restricting Largest Contentful Paint to a limited set of element types was intentional in order to reduce complexity.
1 quote from 1 source
Note that restricting the elements to this limited set was intentional in order to reduce complexity.
- web.dev states that Largest Contentful Paint measurements use heuristics to exclude certain elements that users are likely to see as non-contentful.
- web.dev states that the elements excluded by Largest Contentful Paint measurements include elements that cover the full viewport.
2 quotes from 1 source
As well as only considering some elements, LCP measurements use heuristics to exclude certain elements that users are likely to see as "non-contentful". For Chromium-based browsers, these include:
Elements that cover the full viewport, that are likely considered as background rather than content
web.dev states that the size of the element reported for Largest Contentful Paint is typically the size that is visible to the user within the viewport.
1 quote from 1 source
The size of the element reported for LCP is typically the size that's visible to the user within the viewport.
web.dev states that for image elements resized from their intrinsic size, the size reported for Largest Contentful Paint is either the visible size or the intrinsic size, whichever is smaller.
1 quote from 1 source
For image elements that have been resized from their intrinsic size, the size that gets reported is either the visible size or the intrinsic size, whichever is smaller.
web.dev states that for all elements, Largest Contentful Paint does not consider margins, paddings, or borders applied using CSS.
1 quote from 1 source
For all elements, LCP doesn't consider margins, paddings, or borders applied using CSS.
web.dev states that for text elements, Largest Contentful Paint considers only the smallest rectangle that can contain all text nodes.
1 quote from 1 source
For text elements, LCP considers only the smallest rectangle that can contain all text nodes.
web.dev states that the browser will stop reporting new Largest Contentful Paint entries as soon as the user interacts with the page via a tap, scroll, or keypress.
1 quote from 1 source
The browser will stop reporting new entries as soon as the user interacts with the page (via a tap, scroll, or keypress), as user interaction often changes what's visible to the user (which is especially true with scrolling).
web.dev states that if the largest contentful element is removed from the viewport or from the DOM, the largest contentful element remains the largest contentful element unless a larger element is rendered.
1 quote from 1 source
If the largest contentful element is removed from the viewport, or even from the DOM, it remains the largest contentful element unless a larger element is rendered.
web.dev states that for analysis purposes you should only report the most recently dispatched Largest Contentful Paint PerformanceEntry to your analytics service.
1 quote from 1 source
For analysis purposes, you should only report the most recently dispatched PerformanceEntry to your analytics service.
Google tools which measure Largest Contentful Paint do not report the metric if the page was loaded in the background.
1 quote from 1 source
Google tools that measure LCP don't report this metric if the page was loaded in the background, as it does not reflect the user-perceived load time.
- web.dev states that Largest Contentful Paint includes unload time from the previous page, connection set up time, redirect time, and other Time To First Byte delays.
- web.dev states that the unload time, connection set up time, redirect time, and other Time To First Byte delays included in Largest Contentful Paint can lead to differences between field and lab measurements.
1 quote from 1 source
It is important to note that LCP includes any unload time from the previous page, connection set up time, redirect time, and other Time To First Byte (TTFB) delays which can be significant when measured in the field and can lead to differences between field and lab measurements.
web.dev's article on defining Core Web Vitals thresholds concludes that 4 seconds is a reasonable "poor" threshold for Largest Contentful Paint.
1 quote from 1 source
Thus, we conclude that 2.5 seconds is a reasonable "good" threshold, and 4 seconds is a reasonable "poor" threshold for Largest Contentful Paint.
web.dev's Core Web Vitals thresholds article classifies a 75th percentile Largest Contentful Paint of…
- 2 seconds as good.
- 5 seconds as poor.
1 quote from 1 source
So, for example, a 75th percentile LCP of 2 seconds is classified as "good", while a 75th percentile LCP of 5 seconds is classified as "poor".
web.dev's Web Vitals article states that to provide a good user experience, Largest Contentful Paint should occur within 2.5 seconds of when the page first starts loading.
1 quote from 1 source
Largest Contentful Paint (LCP): measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading.
- Web Vitals | Articles | web.dev web.dev
Largest Contentful Paint's documented position, according to web.dev's Web Vitals article, is that tools assessing Core Web Vitals compliance should consider a page passing if it meets the recommended targets at the 75th percentile for all three metrics.
1 quote from 1 source
Tools that assess Core Web Vitals compliance should consider a page passing if it meets the recommended targets at the 75th percentile for all three of the Core Web Vitals metrics.
- Web Vitals | Articles | web.dev web.dev
Measured finding6
Something someone actually measured, with the method attached.
web.dev's Core Web Vitals thresholds article reports that the 1.5 second Largest Contentful Paint threshold is not consistently achievable
1 quote from 1 source
We find that the 1.5 and 2 second thresholds are not consistently achievable, while 2.5 seconds is consistently achievable.
The Chromium metrics changelog reports that the impact of the transparent-text exclusion on Largest Contentful Paint ecosystem metrics was…
- minimal.
- not statistically significant.
2 quotes from 1 source
## Exclude transparent text from LCP
We observed that this feature’s impact on ecosystem metrics was minimal and not statistically significant.
- The Chromium metrics changelog reports that the Chrome 83 change, which stopped Largest Contentful Paint measurement at input or scroll in any frame, produced a roughly 5% drop at the 75th percentile across all sites that use frames.
- The Chrome 83 change stopped Largest Contentful Paint measurement at input or scroll in any frame.
3 quotes from 1 source
Two bugs in the implementation of Largest Contentful Paint (LCP) were fixed in Chrome 83:
For the change that stops measuring LCP at input or scroll in any frame, we see a reduction in LCP at the higher percentiles on Android only (not desktop). Across all sites that use frames, we see the following impact.
At the 75th percentile, a ~5% drop
web.dev's Core Web Vitals thresholds article labels its table of candidate Largest Contentful Paint thresholds as the percentage of CrUX origins classified as poor as of April 2020.
1 quote from 1 source
% of CrUX origins classified as "poor" for candidate LCP thresholds as of April 2020
Changed on19
A dated change. This is where advice quietly stops being true.
A slightly coarsened render time for Largest Contentful Paint…
- is available from Chrome 133 even when Timing-Allow-Origin is not provided.
- was resolved in late 2024.
1 quote from 1 source
This was resolved in late 2024 and a slightly coarsened render time is available from Chrome 133 even when Timing-Allow-Origin is not provided.
In Chrome 130, transparent text with no visible decorations like shadows and strokes was made ineligible for Largest Contentful Paint, having previously been eligible.
2 quotes from 1 source
# Largest Contentful Paint Change in Chrome 130
When texts are transparent, and with no visible decorations like shadows, and strokes, they should be not eligible for LCP. But previously they are. We fixed this and did experiment to see if the fix would have impact on the LCP metric.
Videos were previously ignored for Largest Contentful Paint unless they had a poster image.
1 quote from 1 source
Videos have previously been ignored for LCP, unless they have a poster image.
The Chromium metrics changelog states that with the Chrome 116 change a video element can become a Largest Contentful Paint candidate, exactly like an image.
2 quotes from 1 source
Starting around Chrome 116, we're making two changes to the way that LCP handles animated images and videos.
With this change, a video element can become an LCP candidate, exactly like an image.
Animated GIFs and PNGs were previously not considered as Largest Contentful Paint candidates until they were fully loaded.
2 quotes from 1 source
Starting around Chrome 116, we're making two changes to the way that LCP handles animated images and videos.
Animated images (animated GIFs and PNGs) were previously not considered as LCP candidates until they were fully loaded.
The Chromium metrics changelog states that the Chrome 116 change to Largest Contentful Paint handling of animated content…
- affects only UKM and CrUX reporting.
- does not affect PerformanceObserver observations measured in JavaScript.
2 quotes from 1 source
Starting around Chrome 116, we're making two changes to the way that LCP handles animated images and videos.
Note for now, this only affects UKM (and so CrUX) reporting of LCP and does not affect PerformanceObserver observations as measured in JavaScript.
In Chrome 112, Largest Contentful Paint began to ignore images with very low content relative to their display sizes.
1 quote from 1 source
In Chrome 112, LCP will begin to ignore images with very low content relative to their display sizes.
For Largest Contentful Paint (LCP)…
- the low-entropy image threshold is 0.05 bits of image data per displayed pixel.
- images below the low-entropy image threshold are not considered for LCP.
1 quote from 1 source
The threshold is currently 0.05 bits of image data per displayed pixel, and images which fall below this threshold will not be considered for LCP.
The Chromium metrics changelog states that the Largest Contentful Paint low-entropy image change was launched to Chrome users starting on roughly April 6, 2023.
1 quote from 1 source
This change was launched to Chrome users starting on roughly April 6, 2023, and was rolled out to existing Chrome installs.
The Chromium metrics changelog states that the Chrome 96 fix made Largest Contentful Paint always use the full page viewport instead of the frame viewport when considering which images to ignore.
2 quotes from 1 source
In Chrome 96, a bug fix was made to the Chrome implementation.
This fixes this issue by always using the full page viewport instead of frame viewport when considering which images to ignore.
The Chromium metrics changelog states that in Chrome 88, full viewport images were no longer considered as the largest contentful paint.
2 quotes from 1 source
In Chrome 88, some bug fixes were made in the chromium implementation.
Full viewport images, which are visually equivalent to background images, are no longer considered as the largest contentful paint.
The Chromium metrics changelog states that in Chrome 88, Largest Contentful Paint stops recording after an input in an out of process iframe.
2 quotes from 1 source
In Chrome 88, some bug fixes were made in the chromium implementation.
Largest Contentful Paint stops recording after an input in an out of process iframe.
- Largest Contentful Paint measurement stops at the first input or scroll on the page.
- In Chrome 83, the Largest Contentful Paint rule correctly accounted for inputs and scrolls in subframes.
1 quote from 1 source
Largest Contentful Paint measurement should stop at the first input or scroll on the page. In Chrome 83, inputs and scrolls in subframes were correctly accounted for.
The Chromium Largest Contentful Paint changelog records that…
- in Chrome 79 the metric was elevated to stable.
- changes in metric definition would from then on be reported in the log.
2 quotes from 1 source
* Chrome 79
Metric is elevated to stable; changes in metric definition will be reported in this log.
Echoed without a primary source3
Widely repeated in the field, but traceable only to other repetitions. Listed because knowing something is merely echoed is worth as much as knowing it is documented.
Parachute Design's guide to Largest Contentful Paint asserts that a strong LCP score…
- reduces bounce on landing pages.
- supports higher conversion rates.
1 quote from 1 source
A strong LCP score reduces bounce on landing pages and supports higher conversion rates.
NitroPack's guide to fixing Largest Contentful Paint asserts that three years after the introduction of Core Web Vitals, 33.3% of websites globally still struggle to pass LCP.
1 quote from 1 source
Three years after the introduction of Core Web Vitals, a staggering 33.3% of websites globally still struggle to pass the notoriously challenging metric – Largest Contentful Paint (LCP).
Refused17
Claims the research produced that the grounding gate would not accept, with its reason. They are here because a site that only shows what passed gives you no way to judge whether the gate does anything.
Show what was refused
The Chrome 130 transparent-text change to Largest Contentful Paint launched the week of Oct 21, 2024.
Refused: The quote states a launch date but does not mention 'transparent-text change'; that specific detail is not supported.
Unsupported: transparent-text change
What it rested on
Launch was the week of Oct 21, 2024, when m130 was in stable, but a limited number of early adopters might have seen this change as early as m126.
The documented position of Largest Contentful Paint is that Google's Search Central documentation on page experience states that Core Web Vitals are used by Google's ranking systems.
Refused: The quote mentions Core Web Vitals generally but does not mention Largest Contentful Paint or its documented position.
Unsupported: documented position of Largest Contentful Paint
What it rested on
What aspects of page experience are used in ranking? Core Web Vitals are used by our ranking systems.
Largest Contentful Paint's documented position, as stated in Google's Search Central documentation on page experience, is that there is no single page experience signal used by Google Search for ranking.
Refused: The quote states there is no single page experience signal but never mentions Largest Contentful Paint.
Unsupported: Largest Contentful Paint's documented position
What it rested on
Is there a single "page experience signal" that Google Search uses for ranking? There is no single signal. Our core ranking systems look at a variety of signals that align with overall page experience.
web.dev states that an element with a background image loaded using the url() function is considered for Largest Contentful Paint, as opposed to a CSS gradient.
Refused: The quote only names the element type and does not state that it is considered for LCP.
Unsupported: is considered for Largest Contentful Paint
What it rested on
An element with a background image loaded using the url() function, (as opposed to a CSS gradient)
web.dev's Core Web Vitals thresholds article states that a site is classified as having good Largest Contentful Paint performance if at least 75 percent of page views meet the good Largest Contentful Paint threshold.
Refused: The quote states the 75% 'good' threshold for 'that metric' but does not specify Largest Contentful Paint.
Unsupported: Largest Contentful Paint
What it rested on
if at least 75 percent of page views to a site meet the "good" threshold, the site is classified as having "good" performance for that metric
web.dev's Web Vitals article states that all Core Web Vitals, of which Largest Contentful Paint is one, are first and foremost field metrics.
Refused: The quote establishes that all Core Web Vitals are field metrics but does not state that Largest Contentful Paint is one of them.
Unsupported: of which Largest Contentful Paint is one
What it rested on
While all of the Core Web Vitals are, first and foremost, field metrics, many of them are also measurable in the lab.
web.dev's Web Vitals article states that many Core Web Vitals, of which Largest Contentful Paint is one, are also measurable in the lab.
Refused: The quote says many Core Web Vitals are measurable in the lab but does not state that Largest Contentful Paint is among them.
Unsupported: of which Largest Contentful Paint is one
What it rested on
While all of the Core Web Vitals are, first and foremost, field metrics, many of them are also measurable in the lab.
web.dev's Web Vitals article states that for Largest Contentful Paint, lab measurement is an essential part of delivering great experiences.
Refused: The quote states lab measurement is essential generally but does not tie it to Largest Contentful Paint.
Unsupported: for Largest Contentful Paint
What it rested on
While lab measurement is an essential part of delivering great experiences, it is not a substitute for field measurement.
web.dev's Web Vitals article states that for Largest Contentful Paint, lab measurement is not a substitute for field measurement.
Refused: The quote makes a general statement about lab versus field measurement but does not specifically mention Largest Contentful Paint.
Unsupported: for Largest Contentful Paint
What it rested on
While lab measurement is an essential part of delivering great experiences, it is not a substitute for field measurement.
web.dev's Core Web Vitals thresholds article reports that at a 4 second Largest Contentful Paint threshold, roughly 26% of phone origins would be classified as poor.
Refused: The quote only says a 4 second threshold, not that it is the Largest Contentful Paint threshold.
Unsupported: Largest Contentful Paint
What it rested on
For a 4 second threshold, roughly 26% of phone origins, and 21% of desktop origins, would be classified as poor.
web.dev's Core Web Vitals thresholds article reports that at a 4 second Largest Contentful Paint threshold, roughly 21% of desktop origins would be classified as poor.
Refused: The quote gives the 21% desktop figure for a 4 second threshold but does not state that this threshold is Largest Contentful Paint.
Unsupported: Largest Contentful Paint threshold
What it rested on
For a 4 second threshold, roughly 26% of phone origins, and 21% of desktop origins, would be classified as poor.
web.dev's Core Web Vitals thresholds article reports that the 2 second Largest Contentful Paint threshold is not consistently achievable
Refused: The quote says the 2 second threshold is not consistently achievable but does not identify it as the Largest Contentful Paint threshold.
Unsupported: Largest Contentful Paint
What it rested on
We find that the 1.5 and 2 second thresholds are not consistently achievable, while 2.5 seconds is consistently achievable.
web.dev's Core Web Vitals thresholds article reports that the 2.5 second Largest Contentful Paint threshold is consistently achievable
Refused: The quote states 2.5 seconds is consistently achievable but does not specify that this threshold is for Largest Contentful Paint.
Unsupported: Largest Contentful Paint
What it rested on
We find that the 1.5 and 2 second thresholds are not consistently achievable, while 2.5 seconds is consistently achievable.
The Chrome 83 change stopping Largest Contentful Paint measurement at input or scroll in any frame produced a roughly 40% drop at the 99th percentile across all sites that use frames.
Refused: The source states this drop occurred on Android only, but the claim omits that restriction.
Unsupported: produced a roughly 40% drop at the 99th percentile across all sites that use frames
What it rested on
Two bugs in the implementation of Largest Contentful Paint (LCP) were fixed in Chrome 83:
For the change that stops measuring LCP at input or scroll in any frame, we see a reduction in LCP at the higher percentiles on Android only (not desktop). Across all sites that use frames, we see the following impact.
At the 99th percentile, a ~40% drop
Google's Search Central documentation on page experience states that getting good Largest Contentful Paint results in reports like Search Console's Core Web Vitals report or third-party tools does not guarantee that pages will rank at the top of Google Search results.
Refused: The quote says good results in Core Web Vitals reports or third-party tools, not specifically Largest Contentful Paint results.
Unsupported: Largest Contentful Paint
What it rested on
Keep in mind that getting good results in reports like Search Console's Core Web Vitals report or third-party tools doesn't guarantee that your pages will rank at the top of Google Search results; there's more to great page experience than Core Web Vitals scores alone.
Google's Search Central documentation on page experience states that trying to get a perfect Core Web Vitals score, which includes Largest Contentful Paint, just for SEO reasons may not be the best use of your time.
Refused: The quote says 'these scores' and 'perfect score' but never names Core Web Vitals or Largest Contentful Paint, so that specific attribution is not established.
Unsupported: Core Web Vitals score, which includes Largest Contentful Paint
What it rested on
These scores are meant to help you to improve your site for your users overall, and trying to get a perfect score just for SEO reasons may not be the best use of your time.
For Largest Contentful Paint, Google's Search Central documentation on page experience states that Google Search always seeks to show the most relevant content even if the page experience is sub-par.
Refused: The cited quote states the general page experience principle but does not tie it to Largest Contentful Paint.
Unsupported: For Largest Contentful Paint
What it rested on
Google Search always seeks to show the most relevant content, even if the page experience is sub-par.