{
 "caniuse": [
  "x-doc-messaging"
 ],
 "compat_features": [
  "api.DedicatedWorkerGlobalScope.message_event",
  "api.DedicatedWorkerGlobalScope.postMessage",
  "api.MessageEvent",
  "api.MessageEvent.MessageEvent",
  "api.MessageEvent.data",
  "api.MessageEvent.lastEventId",
  "api.MessageEvent.origin",
  "api.MessageEvent.source",
  "api.Window.message_event",
  "api.Window.postMessage",
  "api.Worker.message_event",
  "api.Worker.postMessage"
 ],
 "description": "The postMessage() global method sends cross-origin messages to windows and workers, including popups and iframes. Also known as cross-document messaging.",
 "description_html": "The <code>postMessage()</code> global method sends cross-origin messages to windows and workers, including popups and iframes. Also known as cross-document messaging.",
 "group": [
  "messaging"
 ],
 "kind": "feature",
 "name": "postMessage",
 "spec": [
  "https://html.spec.whatwg.org/multipage/web-messaging.html#web-messaging"
 ],
 "status": {
  "baseline": "high",
  "baseline_high_date": "2018-01-29",
  "baseline_low_date": "2015-07-29",
  "by_compat_key": {
   "api.DedicatedWorkerGlobalScope.message_event": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "4",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3.5",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "5"
    }
   },
   "api.DedicatedWorkerGlobalScope.postMessage": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "4",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3.5",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "5"
    }
   },
   "api.MessageEvent": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.MessageEvent.MessageEvent": {
    "baseline": "high",
    "baseline_high_date": "2019-02-02",
    "baseline_low_date": "2016-08-02",
    "support": {
     "chrome": "16",
     "chrome_android": "18",
     "edge": "14",
     "firefox": "26",
     "firefox_android": "26",
     "safari": "6",
     "safari_ios": "6"
    }
   },
   "api.MessageEvent.data": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.MessageEvent.lastEventId": {
    "baseline": "high",
    "baseline_high_date": "2020-10-30",
    "baseline_low_date": "2018-04-30",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "17",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.MessageEvent.origin": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.MessageEvent.source": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.Window.message_event": {
    "baseline": "high",
    "baseline_high_date": "2020-02-01",
    "baseline_low_date": "2017-08-01",
    "support": {
     "chrome": "60",
     "chrome_android": "60",
     "edge": "12",
     "firefox": "9",
     "firefox_android": "9",
     "safari": "4",
     "safari_ios": "4"
    }
   },
   "api.Window.postMessage": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "3.2"
    }
   },
   "api.Worker.message_event": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "4",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3.5",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "5"
    }
   },
   "api.Worker.postMessage": {
    "baseline": "high",
    "baseline_high_date": "2018-01-29",
    "baseline_low_date": "2015-07-29",
    "support": {
     "chrome": "2",
     "chrome_android": "18",
     "edge": "12",
     "firefox": "3.5",
     "firefox_android": "4",
     "safari": "4",
     "safari_ios": "5"
    }
   }
  },
  "support": {
   "chrome": "2",
   "chrome_android": "18",
   "edge": "12",
   "firefox": "3",
   "firefox_android": "4",
   "safari": "4",
   "safari_ios": "3.2"
  }
 },
 "id": "postmessage",
 "groups": [
  "messaging"
 ],
 "specs": [
  {
   "url": "https://html.spec.whatwg.org/multipage/web-messaging.html#web-messaging",
   "seriesComposition": "full",
   "shortname": "html",
   "series": {
    "shortname": "html",
    "currentSpecification": "html",
    "title": "HTML",
    "shortTitle": "HTML",
    "nightlyUrl": "https://html.spec.whatwg.org/multipage/"
   },
   "nightly": {
    "url": "https://html.spec.whatwg.org/multipage/",
    "status": "Living Standard",
    "sourcePath": "source",
    "alternateUrls": [],
    "repository": "https://github.com/whatwg/html",
    "pages": [
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     "https://html.spec.whatwg.org/multipage/infrastructure.html",
     "https://html.spec.whatwg.org/multipage/common-microsyntaxes.html",
     "https://html.spec.whatwg.org/multipage/urls-and-fetching.html",
     "https://html.spec.whatwg.org/multipage/common-dom-interfaces.html",
     "https://html.spec.whatwg.org/multipage/structured-data.html",
     "https://html.spec.whatwg.org/multipage/dom.html",
     "https://html.spec.whatwg.org/multipage/semantics.html",
     "https://html.spec.whatwg.org/multipage/sections.html",
     "https://html.spec.whatwg.org/multipage/grouping-content.html",
     "https://html.spec.whatwg.org/multipage/text-level-semantics.html",
     "https://html.spec.whatwg.org/multipage/links.html",
     "https://html.spec.whatwg.org/multipage/edits.html",
     "https://html.spec.whatwg.org/multipage/embedded-content.html",
     "https://html.spec.whatwg.org/multipage/images.html",
     "https://html.spec.whatwg.org/multipage/iframe-embed-object.html",
     "https://html.spec.whatwg.org/multipage/media.html",
     "https://html.spec.whatwg.org/multipage/image-maps.html",
     "https://html.spec.whatwg.org/multipage/embedded-content-other.html",
     "https://html.spec.whatwg.org/multipage/tables.html",
     "https://html.spec.whatwg.org/multipage/forms.html",
     "https://html.spec.whatwg.org/multipage/input.html",
     "https://html.spec.whatwg.org/multipage/form-elements.html",
     "https://html.spec.whatwg.org/multipage/form-control-infrastructure.html",
     "https://html.spec.whatwg.org/multipage/interactive-elements.html",
     "https://html.spec.whatwg.org/multipage/scripting.html",
     "https://html.spec.whatwg.org/multipage/canvas.html",
     "https://html.spec.whatwg.org/multipage/custom-elements.html",
     "https://html.spec.whatwg.org/multipage/semantics-other.html",
     "https://html.spec.whatwg.org/multipage/microdata.html",
     "https://html.spec.whatwg.org/multipage/interaction.html",
     "https://html.spec.whatwg.org/multipage/dnd.html",
     "https://html.spec.whatwg.org/multipage/popover.html",
     "https://html.spec.whatwg.org/multipage/browsers.html",
     "https://html.spec.whatwg.org/multipage/nav-history-apis.html",
     "https://html.spec.whatwg.org/multipage/document-sequences.html",
     "https://html.spec.whatwg.org/multipage/browsing-the-web.html",
     "https://html.spec.whatwg.org/multipage/document-lifecycle.html",
     "https://html.spec.whatwg.org/multipage/speculative-loading.html",
     "https://html.spec.whatwg.org/multipage/webappapis.html",
     "https://html.spec.whatwg.org/multipage/dynamic-markup-insertion.html",
     "https://html.spec.whatwg.org/multipage/timers-and-user-prompts.html",
     "https://html.spec.whatwg.org/multipage/system-state.html",
     "https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html",
     "https://html.spec.whatwg.org/multipage/comms.html",
     "https://html.spec.whatwg.org/multipage/server-sent-events.html",
     "https://html.spec.whatwg.org/multipage/web-messaging.html",
     "https://html.spec.whatwg.org/multipage/workers.html",
     "https://html.spec.whatwg.org/multipage/worklets.html",
     "https://html.spec.whatwg.org/multipage/webstorage.html",
     "https://html.spec.whatwg.org/multipage/syntax.html",
     "https://html.spec.whatwg.org/multipage/parsing.html",
     "https://html.spec.whatwg.org/multipage/named-characters.html",
     "https://html.spec.whatwg.org/multipage/xhtml.html",
     "https://html.spec.whatwg.org/multipage/rendering.html",
     "https://html.spec.whatwg.org/multipage/obsolete.html",
     "https://html.spec.whatwg.org/multipage/iana.html",
     "https://html.spec.whatwg.org/multipage/indices.html",
     "https://html.spec.whatwg.org/multipage/references.html",
     "https://html.spec.whatwg.org/multipage/acknowledgements.html"
    ],
    "filename": "index.html"
   },
   "organization": "WHATWG",
   "groups": [
    {
     "name": "HTML Workstream",
     "url": "https://html.spec.whatwg.org/multipage/"
    }
   ],
   "title": "HTML",
   "source": "whatwg",
   "shortTitle": "HTML",
   "categories": [
    "browser"
   ],
   "standing": "good",
   "tests": {
    "repository": "https://github.com/web-platform-tests/wpt",
    "testPaths": [
     "close-watcher",
     "custom-elements",
     "eventsource",
     "html",
     "imagebitmap-renderingcontext",
     "import-maps",
     "navigation-api",
     "webmessaging",
     "webstorage",
     "workers",
     "worklets",
     "x-frame-options"
    ],
    "excludePaths": [
     "html/cross-origin-embedder-policy/credentialless",
     "html/dom/partial-updates/tentative",
     "html/cross-origin-embedder-policy/credentialless"
    ]
   },
   "fragment": "web-messaging"
  }
 ],
 "mdnUrls": [
  {
   "slug": "Web/API/Window/postMessage",
   "title": "Window: postMessage() method",
   "anchor": null,
   "url": "https://developer.mozilla.org/docs/Web/API/Window/postMessage"
  },
  {
   "slug": "Web/API/Worker/postMessage",
   "title": "Worker: postMessage() method",
   "anchor": null,
   "url": "https://developer.mozilla.org/docs/Web/API/Worker/postMessage"
  }
 ],
 "standardPositions": [],
 "hasNegativeStandardPosition": false,
 "stateOfSurveys": [],
 "chromeUseCounters": {},
 "interop": [],
 "wpt": {
  "url": "https://wpt.fyi/results?q=feature:postmessage"
 },
 "developerSignals": null,
 "bugs": {
  "chrome": [
   "https://crbug.com/861735",
   "https://bugs.chromium.org/p/chromium/issues/detail?id=425896",
   "http://crbug.com/158865"
  ]
 },
 "baselineLowDateAsObject": "2015-07-29T00:00:00.000Z",
 "baselineHighDateAsObject": "2018-01-29T00:00:00.000Z"
}