largest-contentful-paint

edit

WPT coverage of the tests of largest-contentful-paint at the revision 5602b0f210e3. The tests link to their results in the browsers on wpt.fyi. The tentative tests (experimental features) and the reftests are listed separately from the stable tests.

Group	Passing	Tests	Pass rate
Stable	63	66	95%
Tentative	4	8	50%
Reftests	0	0	–
All	67	74	91%

Failure reasons

The tests that do not pass (failing or disabled), by kind of reason. A test with several reasons counts once per kind.

NOT IMPLEMENTED: 7

Stable tests

Test	Result	Subtests	Kind	Description
`background-image-set-image.html`	Pass	1 / 1
`broken-image-icon.html`	Pass	1 / 1
`contracted-image.html`	Pass	1 / 1
`cross-origin-image.sub.html`	Pass	1 / 1
`element-only-when-fully-active.html`	Pass	1 / 1
`expanded-image.html`	Pass	1 / 1
`first-letter-background.html`	Pass	1 / 1
`first-paint-equals-lcp-text.html`	Pass	1 / 1
`idlharness.html`	Pass	30 / 30
`iframe-content-not-observed.html`	Pass	1 / 1
`image-TAO.sub.html`	Pass	1 / 1
`image-element-when-fully-active.html`	Pass	1 / 1
`image-full-viewport.html`	Pass	1 / 1
`image-inside-svg.html`	Pass	1 / 1
`image-not-fully-visible.html`	Pass	1 / 1
`image-removed-after-paint.html`	Pass	1 / 1
`image-removed-before-load.html`	Pass	1 / 1
`image-src-change.html`	Pass	1 / 1
`image-sw-same-origin.https.html`	Pass	1 / 1
`image-upscaling-empty-url.html`	Pass	10 / 10
`image-upscaling.html`	Pass	10 / 10
`initially-invisible-images.html`	Pass	1 / 1
`invisible-images-composited-1.html`	Pass	1 / 1
`invisible-images-composited-2.html`	Pass	1 / 1
`invisible-images.html`	Pass	1 / 1
`larger-image.html`	Pass	1 / 1
`larger-text.html`	Pass	1 / 1
`loadTime-after-appendChild.html`	Pass	1 / 1
`modified-text-not-reconsidered.html`	Pass	1 / 1
`multiple-image-same-src.html`	Pass	1 / 1
`multiple-redirects-TAO.html`	Pass	1 / 1
`observe-after-untrusted-scroll.html`	Pass	1 / 1
`observe-css-generated-image.html`	Pass	1 / 1
`observe-css-generated-text.html`	Pass	3 / 3
`observe-image.html`	Pass	1 / 1
`observe-mathml.html`	Pass	1 / 1
`observe-random-namespace.html`	Pass	1 / 1
`observe-svg-background-image.html`	Pass	1 / 1
`observe-svg-data-uri-background-image.html`	Pass	1 / 1
`observe-svg-data-uri-image.html`	Pass	1 / 1
`observe-svg-image.html`	Pass	1 / 1
`observe-text.html`	Pass	1 / 1
`performance-entry-sequence.html`	Pass	1 / 1
`placeholder-image.html`	Pass	1 / 1
`progressively-loaded-image.html`	Pass	1 / 1
`pseudo-content-image.html`	Pass	1 / 1
`redirects-tao-star.html`	Pass	1 / 1
`repeated-image.html`	Pass	1 / 1
`resized-image-not-reconsidered.html`	Pass	1 / 1
`same-origin-redirects.html`	Pass	1 / 1
`supported-lcp-type.html`	Pass	1 / 1
`text-fragment-union.html`	Pass	1 / 1
`text-with-display-style.html`	Pass	1 / 1
`toJSON.html`	Pass	1 / 1
`transparent-text-with-shadow.html`	Pass	1 / 1
`transparent-text-with-text-stroke.html`	Pass	1 / 1
`transparent-text.html`	Pass	1 / 1
`update-on-style-change.html`	Pass	1 / 1
`video-data-uri.html`	Timeout	0 / 1	NOT IMPLEMENTED	the frames of a video are not candidates of the largest contentful paint (only Chromium reports them)
`video-play-after-poster.html`	Pass	1 / 1
`video-poster.html`	Pass	1 / 1
`web-font-styled-text-resize-block.html`	Pass	1 / 1
`web-font-styled-text-resize-swap-after-interaction.html`	Pass	1 / 1
`web-font-styled-text-resize-swap-smaller.html`	Pass	1 / 1
`web-font-styled-text-resize-swap-subnode.html`	Fail	0 / 1	NOT IMPLEMENTED	the paints are only computed once a script observes or reads the paint timing entries: the test observes them (`buffered`) after the web font is loaded, so the text painted with the fallback font is not reported and there is 1 entry instead of 2; the same assertion fails in Chrome, Firefox and Safari on wpt.fyi
`web-font-styled-text-resize-swap.html`	Fail	0 / 1	NOT IMPLEMENTED	the paints are only computed once a script observes or reads the paint timing entries: the test observes them (`buffered`) after the web font is loaded, so the text painted with the fallback font is not reported and there is 1 entry instead of 2; the same assertion fails in Chrome, Firefox and Safari on wpt.fyi

Tentative tests

Test	Result	Subtests	Kind	Description
`animated/observe-animated-image-gif.tentative.html`	Fail	0 / 1	NOT IMPLEMENTED	the first frame of an animated image is not painted before the whole image is received (the image is available once it is completely loaded), so `renderTime` is after the 2 s delay of the second frame; the same assertion fails in Chrome, Firefox and Safari on wpt.fyi
`animated/observe-animated-image-webp.tentative.html`	Fail	0 / 1	NOT IMPLEMENTED	the first frame of an animated image is not painted before the whole image is received (the image is available once it is completely loaded), so `renderTime` is after the 2 s delay of the second frame; the same assertion fails in Chrome, Firefox and Safari on wpt.fyi
`animated/observe-animated-image.tentative.html`	Fail	0 / 1	NOT IMPLEMENTED	the first frame of an animated image is not painted before the whole image is received (the image is available once it is completely loaded), so `renderTime` is after the 2 s delay of the second frame; the same assertion fails in Chrome, Firefox and Safari on wpt.fyi
`animated/observe-cross-origin-animated-image.tentative.html`	Pass	1 / 1
`animated/observe-cross-origin-tao-animated-image.tentative.html`	Pass	1 / 1
`animated/observe-non-animated-image.tentative.html`	Pass	1 / 1
`animated/observe-video.tentative.html`	Timeout	0 / 1	NOT IMPLEMENTED	the frames of a video are not candidates of the largest contentful paint (only Chromium reports them)
`observe-pseudo-element.tentative.html`	Pass	1 / 1