{
 "compat_features": [
  "css.selectors.open"
 ],
 "description": "The :open CSS pseudo-class matches elements that have open states, like <details>, <dialog>, or <select>, based on their state.",
 "description_html": "The <code>:open</code> CSS pseudo-class matches elements that have open states, like <code>&#x3C;details></code>, <code>&#x3C;dialog></code>, or <code>&#x3C;select></code>, based on their state.",
 "group": [
  "selectors"
 ],
 "kind": "feature",
 "name": ":open",
 "spec": [
  "https://drafts.csswg.org/selectors-4/#open-state"
 ],
 "status": {
  "baseline": "low",
  "baseline_low_date": "2026-05-11",
  "by_compat_key": {
   "css.selectors.open": {
    "baseline": "low",
    "baseline_low_date": "2026-05-11",
    "support": {
     "chrome": "133",
     "chrome_android": "133",
     "edge": "133",
     "firefox": "136",
     "firefox_android": "136",
     "safari": "26.5",
     "safari_ios": "26.5"
    }
   }
  },
  "support": {
   "chrome": "133",
   "chrome_android": "133",
   "edge": "133",
   "firefox": "136",
   "firefox_android": "136",
   "safari": "26.5",
   "safari_ios": "26.5"
  }
 },
 "id": "open-pseudo",
 "groups": [
  "selectors"
 ],
 "specs": [
  {
   "url": "https://drafts.csswg.org/selectors-4/#open-state",
   "seriesComposition": "full",
   "shortname": "selectors-4",
   "series": {
    "shortname": "selectors",
    "currentSpecification": "selectors-4",
    "title": "Selectors",
    "shortTitle": "Selectors",
    "releaseUrl": "https://www.w3.org/TR/selectors/",
    "nightlyUrl": "https://drafts.csswg.org/selectors/"
   },
   "seriesVersion": "4",
   "seriesPrevious": "selectors-3",
   "seriesNext": "selectors-5",
   "organization": "W3C",
   "groups": [
    {
     "name": "Cascading Style Sheets (CSS) Working Group",
     "url": "https://www.w3.org/groups/wg/css/"
    }
   ],
   "release": {
    "url": "https://www.w3.org/TR/selectors-4/",
    "status": "Working Draft",
    "filename": "Overview.html"
   },
   "nightly": {
    "url": "https://drafts.csswg.org/selectors-4/",
    "status": "Editor's Draft",
    "alternateUrls": [
     "https://w3c.github.io/csswg-drafts/selectors-4/",
     "https://w3c.github.io/csswg-drafts/selectors/"
    ],
    "repository": "https://github.com/w3c/csswg-drafts",
    "sourcePath": "selectors-4/Overview.bs",
    "filename": "index.html"
   },
   "title": "Selectors Level 4",
   "source": "w3c",
   "shortTitle": "Selectors 4",
   "categories": [
    "browser"
   ],
   "standing": "good",
   "tests": {
    "repository": "https://github.com/web-platform-tests/wpt",
    "testPaths": [
     "css/selectors"
    ]
   },
   "fragment": "open-state"
  }
 ],
 "mdnUrls": [
  {
   "slug": "Web/CSS/Reference/Selectors/:open",
   "title": "`:open` CSS pseudo-class",
   "anchor": null,
   "url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Selectors/:open"
  }
 ],
 "standardPositions": [],
 "hasNegativeStandardPosition": false,
 "stateOfSurveys": [],
 "chromeUseCounters": {},
 "interop": [
  {
   "year": 2026,
   "label": "interop-2026-dialogs-and-popovers",
   "url": "https://wpt.fyi/interop-2026?feature=interop-2026-dialogs-and-popovers"
  }
 ],
 "wpt": {
  "url": "https://wpt.fyi/results?q=feature:open-pseudo"
 },
 "developerSignals": null,
 "bugs": {
  "chrome": [
   "https://issues.chromium.org/issues/324293874"
  ]
 },
 "baselineLowDateAsObject": "2026-05-11T00:00:00.000Z",
 "baselineHighDateAsObject": null,
 "expectedBaselineHighDate": "2028-11-11"
}