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WPT

This page compares scores on the Web Platform Tests across web engines, using the latest master runs from wpt.fyi and Blitz's own test runner.

wpt / intersection-observer

Spec: Intersection Observer ↗

Runs: Chrome 158.0.8110.0 (wpt@d6615bd69, 2026-10-18) | Firefox 160.0a1 (wpt@b58866519, 2026-10-18) | Safari 254 preview (wpt@470a7adf8, 2026-10-18) | Ladybird 1.0-44fe0 (wpt@850b36a56, 2026-10-18) | Servo Servo 0.7 (wpt@df642c414, 2026-10-17) | Blitz fb8d6c15e (wpt@cd1d8aa5b, 2026-10-17)

Score history

Percentage of subtests passing over time, one master run per day. Every engine's percentage is relative to the same denominator: the total number of subtests known to any engine in the latest runs (so lines are not distorted by tests being added to WPT, and an engine that skips tests is not flattered for it).

1 month3 months6 months1 year2 years4 yearsAll time
0%20%40%60%80%100%Nov 2025Dec 2025Jan 2026Feb 2026Mar 2026Apr 2026May 2026Jun 2026Jul 2026Aug 2026Sep 2026Oct 2026ChromeFirefoxSafariLadybirdServo

Sort: alphabetical | by subtest count

AreaChromeFirefoxSafariLadybirdServoBlitz
Total93.1%393/42275.8%320/42282.9%350/42268.9%291/42273.4%310/4220.0%0/422
v278.5%55/7021.4%15/7021.4%15/7030.0%21/7045.7%32/700.0%0/70
TestChromeFirefoxSafariLadybirdServoBlitz
Total96.0%338/35286.6%305/35295.1%335/35276.7%270/35278.9%278/352NO DATA
animating.htmlPASSPASSFAILFAILPASSNOT RUN
bounding-box.html5/55/55/54/54/5NOT RUN
callback-cross-realm-report-exception.htmlPASSPASSPASSPASSPASSNOT RUN
client-rect.html2/22/22/22/22/2NOT RUN
clip-path-animation.htmlPASSFAILFAILFAILFAILNOT RUN
clip-path.htmlPASSFAILFAILFAILFAILNOT RUN
containing-block.html5/55/55/55/55/5NOT RUN
cross-document-root.html2/22/22/21/22/2NOT RUN
cross-origin-iframe.sub.html5/53/55/51/51/5NOT RUN
cross-origin-tall-iframe-rendering.sub.htmlPASSPASSPASSPASSPASSNOT RUN
cross-origin-tall-iframe.sub.htmlPASSPASSPASSFAILFAILNOT RUN
disconnect.html3/33/33/33/33/3NOT RUN
display-contents.htmlPASSPASSPASSPASSPASSNOT RUN
display-none.htmlPASSPASSPASSFAILPASSNOT RUN
document-scrolling-element-root.html2/22/22/22/22/2NOT RUN
edge-inclusive-intersection.html5/55/55/55/55/5NOT RUN
empty-root-margin.htmlPASSPASSPASSPASSPASSNOT RUN
explicit-root-different-document.htmlPASSPASSPASSPASSPASSNOT RUN
fixed-position-child-scroll.html3/33/33/33/33/3NOT RUN
fixed-position-iframe-scroll.html3/33/33/33/33/3NOT RUN
fixed-position-scroll.html3/33/33/33/33/3NOT RUN
grow-height-and-scrolled.html3/33/33/33/33/3NOT RUN
idlharness.window.html49/5043/5045/5048/5050/50NOT RUN
iframe-no-root-with-wrapping-scroller.html5/55/55/52/55/5NOT RUN
iframe-no-root.html5/55/55/52/55/5NOT RUN
iframe-root-with-overflow-propagation.html3/33/33/33/33/3NOT RUN
img-lazy-loading-not-blocked-by-img-outside-viewport.htmlPASSPASSPASSPASSFAILNOT RUN
initial-observation-with-threshold.html3/33/33/31/33/3NOT RUN
inline-client-rect.html3/31/33/31/31/3NOT RUN
inline-with-block-child-client-rect.html2/22/22/22/22/2NOT RUN
intersection-ratio-ib-split.html2/22/22/22/22/2NOT RUN
intersection-ratio-with-fractional-bounds-2.htmlPASSPASSPASSPASSPASSNOT RUN
intersection-ratio-with-fractional-bounds-in-iframe.htmlPASSPASSPASSPASSPASSNOT RUN
intersection-ratio-with-fractional-bounds.htmlPASSPASSPASSPASSPASSNOT RUN
isIntersecting-change-events.html5/55/55/55/55/5NOT RUN
isIntersecting-threshold.html3/33/33/33/33/3NOT RUN
multicol-2.htmlFAILPASSPASSPASSPASSNOT RUN
multicol.htmlFAILPASSPASSPASSPASSNOT RUN
multiple-targets.html5/55/55/55/55/5NOT RUN
multiple-thresholds.html10/1010/1010/1010/1010/10NOT RUN
nested-cross-origin-iframe.sub.htmlPASSPASSPASSPASSFAILNOT RUN
not-in-containing-block-chain.htmlPASSPASSPASSPASSPASSNOT RUN
observe-after-unobserve.htmlPASSPASSPASSPASSPASSNOT RUN
observer-attributes.html9/99/99/99/99/9NOT RUN
observer-callback-arguments.htmlPASSPASSPASSPASSPASSNOT RUN
observer-exceptions.html9/99/99/99/99/9NOT RUN
observer-without-js-reference.html3/33/33/33/33/3NOT RUN
padding-clip.htmlPASSPASSPASSPASSPASSNOT RUN
reinsert-element.htmlPASSPASSPASSPASSPASSNOT RUN
remove-element.html6/66/66/62/66/6NOT RUN
root-is-table-with-overflow-scroll.html3/31/33/33/33/3NOT RUN
root-margin-in-same-origin-iframe.htmlPASSPASSPASSPASSPASSNOT RUN
root-margin-root-element.html7/77/77/73/77/7NOT RUN
root-margin-rounding.htmlPASSPASSPASSFAILPASSNOT RUN
root-margin-scroll-margin-units.html14/142/1414/146/142/14NOT RUN
root-margin.html2/52/52/55/55/5NOT RUN
root-vertical-rl.html3/33/32/31/31/3NOT RUN
rtl-clipped-root.html2/22/22/22/22/2NOT RUN
same-document-no-root.html4/44/44/44/44/4NOT RUN
same-document-root.html7/77/77/73/77/7NOT RUN
same-document-with-document-root.html3/33/33/33/33/3NOT RUN
same-document-zero-size-target.html4/44/44/44/44/4NOT RUN
same-origin-grand-child-iframe.sub.htmlFAILPASSPASSFAILFAILNOT RUN
scroll-and-root-margin.htmlPASSPASSPASSPASSFAILNOT RUN
scroll-margin-4-val.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-clip-path.htmlPASSFAILFAILFAILFAILNOT RUN
scroll-margin-dynamic.html2/22/22/20/22/2NOT RUN
scroll-margin-horizontal.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-iframe.html2/22/22/21/21/2NOT RUN
scroll-margin-nested-2.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-nested-3.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-nested.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-no-intersect.htmlPASSPASSPASSFAILPASSNOT RUN
scroll-margin-non-scrolling-root.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-not-contained.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-percent.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-propagation.html0/33/33/32/31/3NOT RUN
scroll-margin-with-border-outline.htmlPASSPASSPASSPASSPASSNOT RUN
scroll-margin-zero.htmlPASSPASSPASSFAILPASSNOT RUN
scroll-margin.htmlPASSPASSPASSPASSPASSNOT RUN
shadow-content.html2/22/22/22/22/2NOT RUN
slotted-target.htmlPASSPASSPASSPASSPASSNOT RUN
svg-clipped-rect-target.html4/43/43/43/41/4NOT RUN
svg-container-element.html3/33/33/33/31/3NOT RUN
svg-group-target.html4/44/44/42/41/4NOT RUN
svg-image.html3/33/33/33/31/3NOT RUN
svg-intersection-with-fractional-bounds-2.html6/61/66/61/61/6NOT RUN
svg-intersection-with-fractional-bounds.html4/41/44/41/41/4NOT RUN
svg-rect-target.html4/44/44/44/41/4NOT RUN
svg-stroke-change.html3/33/33/33/31/3NOT RUN
svg-target-changes-position.html3/33/33/33/31/3NOT RUN
svg-transformed-rect-target.html4/44/44/42/41/4NOT RUN
svg-viewbox.html3/33/33/33/31/3NOT RUN
target-in-detached-document.html3/31/33/31/31/3NOT RUN
target-in-different-window.htmlPASSFAILTIMEOUTFAILPASSNOT RUN
target-is-root.htmlPASSPASSPASSPASSPASSNOT RUN
text-target.html4/44/44/41/44/4NOT RUN
thresholds-frozen-array.htmlPASSFAILPASSPASSPASSNOT RUN
timestamp.html3/33/33/32/33/3NOT RUN
transform-animation.htmlPASSPASSPASSPASSFAILNOT RUN
transformed-iframe-001-cross-origin.html2/32/32/33/32/3NOT RUN
transformed-iframe-001-same-origin.html2/33/32/31/30/3NOT RUN
transformed-iframe-002-cross-origin.html2/22/22/22/21/2NOT RUN
transformed-iframe-002-same-origin.html2/22/22/21/21/2NOT RUN
transformed-iframe-003-cross-origin.html2/22/22/22/22/2NOT RUN
transformed-iframe-003-same-origin.html1/21/22/20/21/2NOT RUN
transformed-iframe-004-cross-origin.html2/22/22/22/22/2NOT RUN
transformed-iframe-004-same-origin.html1/21/22/20/21/2NOT RUN
transformed-non-invertible-iframe-cross-origin-crash.sub.htmlPASSPASSPASSPASSPASSNOT RUN
transformed-non-invertible-iframe-same-origin-crash.htmlPASSPASSPASSPASSPASSNOT RUN
unclipped-root.html3/33/33/33/33/3NOT RUN
visibility-hidden.html3/33/33/33/33/3NOT RUN
zero-area-element-hidden.html2/22/22/22/22/2NOT RUN
zero-area-element-visible.html2/22/22/22/22/2NOT RUN
zoom-scaled-target.html2/22/22/21/21/2NOT RUN