Hey all, It's great to see this highly requested feature completed! The test suite <https://wpt.fyi/results/css/css-gaps?label=experimental&label=master&aligned> looks quite big in terms of number of tests, and tests across layout models, but there are 9 failing tests <https://wpt.fyi/results/css/css-gaps?label=master&label=experimental&aligned&q=chrome%3A%21ok%20chrome%3A%21pass>. Are the reasons for these failures understood? It it feasible to fix them all?
Best regards, Philip On Tue, Apr 28, 2026 at 9:25 PM 'Sam Davis Omekara' via blink-dev < [email protected]> wrote: > *Contact emails* > [email protected], [email protected], [email protected], > [email protected] > > *Explainer* > > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/CSSGapDecorations/explainer.md > > *Specification* > https://drafts.csswg.org/css-gaps-1 > > *Summary* > CSS Gap Decorations enables styling of gaps in container layouts like Grid > and Flexbox, similar to ‘column-rule’ in multicol layout. This feature is > highly requested by web authors who must use hacks to style the gaps in > Grid and Flexbox layouts today. > > *Blink component* > Blink>Layout > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ELayout%22> > > *Web Feature ID* > gap-decorations <https://webstatus.dev/features/gap-decorations> > > *Motivation* > Today, web authors rely on non-ergonomic workarounds such as the following > examples to apply styles to the gaps in Grid and Flexbox layouts: > https://www.smashingmagazine.com/2017/09/css-grid-gotchas-stumbling-blocks/#how-do-i-add-backgrounds-and-borders-to-grid-areas > https://x.com/geddski/status/1004731709764534274 CSS Gap Decorations > will allow authors to avoid such workarounds and apply styles in a seamless > manner provided by the platform. > > *Initial public proposal* > https://github.com/w3c/csswg-drafts/issues/10393 > > *Search tags* > grid <https://chromestatus.com/features#tags:grid>, flexbox > <https://chromestatus.com/features#tags:flexbox>, multicol > <https://chromestatus.com/features#tags:multicol>, column > <https://chromestatus.com/features#tags:column>, row > <https://chromestatus.com/features#tags:row>, gap > <https://chromestatus.com/features#tags:gap>, decoration > <https://chromestatus.com/features#tags:decoration> > > *TAG review* > https://github.com/w3ctag/design-reviews/issues/1035 > > *TAG review status* > Issues addressed > > > *Risks* > > > *Interoperability and Compatibility* > Gap Decorations is a highly requested feature among web developers. Early > discussions within the CSSWG meeting did not highlight any major concerns > from other browser vendors so far. See discussions on: > https://github.com/w3c/csswg-drafts/issues/10393 > > *Gecko*: Positive ( > https://github.com/mozilla/standards-positions/issues/1158) > > *WebKit*: No signal ( > https://github.com/WebKit/standards-positions/issues/444) > > *Web developers*: Positive Developers are excited about the CSS Gap > Decoration feature. See discussions around this here: > https://github.com/w3c/csswg-drafts/issues/10393 > > This also surfaced as a most requested missing feature in State of CSS > 2023. https://2023.stateofcss.com/en-US/usage/#css_missing_features > > The chromium tracking issue (https://issues.chromium.org/issues/357648037) > has 18 upvotes from developers. > > Following dev trials, the feature drew substantial enthusiasm across web > developer channels: > > Social media: > - > https://www.linkedin.com/pulse/day-164-new-way-style-gaps-emiliano-pisu-x0h1f > > - https://mastodon.social/@anatudor/114201225562770826 > - https://app.daily.dev/posts/a-new-way-to-style-gaps-in-css-9lolqu2yp > - https://x.com/Manz/status/1968682837453799570 > - https://x.com/shadeed9/status/1822025452476592630 > - > https://www.linkedin.com/posts/kirangrandhi_goodbye-to-css-hackshello-to-native-gap-activity-7341108234121900034-_ObL > > > Articles and videos: > - https://www.alwaystwisted.com/articles/styling-the-gap-with-css > - https://youtu.be/L1-7dFQFb1c > - https://css-tricks.com/the-gap-strikes-back-now-stylable/ > - https://heydesigner.com/newsletter/product-design-2025/ > > *Other signals*: > > *WebView application risks* > *Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications?* > There are no WebView application risks. > > > *Debuggability* > DevTools already provides a layout overlay for gaps in Grid and Flexboxes. > Computed values for new properties introduced for gap decoration will be > exposed. > > *Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)?* > Yes > > *Is this feature fully tested by **web-platform-tests* > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > *?* > Yes > https://wpt.fyi/results/css/css-gaps > > *Flag name on about://flags* > enable-experimental-web-platform-features > > *Finch feature name* > CSSGapDecoration > > *Rollout plan* > Will ship enabled for all users > > *Requires code in //chrome?* > False > > *Tracking bug* > https://issues.chromium.org/issues/357648037 > > *Estimated milestones* > Shipping on desktop > 149 > DevTrial on desktop > 139 > Shipping on Android > 149 > Shipping on WebView > 149 > > > *Anticipated spec changes* > *Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way).* > There are no open issues affecting the current level of the spec. All open > issues are scoped to a future level of the spec and do not introduce web > compat or interop risk for what is shipping now. > > *Link to entry on the Chrome Platform Status* > https://chromestatus.com/feature/5157805733183488?gate=6254826279927808 > > *Links to previous Intent discussions* > Intent to Prototype: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/PH8PR00MB1471DB453B0D0025F83B1F06D8BA2%40PH8PR00MB1471.namprd00.prod.outlook.com > Ready for Trial: > https://groups.google.com/a/chromium.org/g/blink-dev/c/vmO3X2aYL2Y/m/f9LLE_W8AAAJ > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CH3PR00MB2681301B231C1C1B50B21206D8372%40CH3PR00MB2681.namprd00.prod.outlook.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CH3PR00MB2681301B231C1C1B50B21206D8372%40CH3PR00MB2681.namprd00.prod.outlook.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAARdPYeNmAdrtMwH0LMj-oURmt%2BYpSa4kjOb2h6Y2ofwiZe_OQ%40mail.gmail.com.
