coderef

CloseWatcherLimited availability

The CloseWatcher API listens and responds to close requests on in-page components, such as modals, popovers, and sidebars.

Not yet supported in all major browsers — check the table and provide a fallback.

Browser support

DesktopChrome
1–125Not supported
126+Supportedsince Jun 11, 2024
Current: 155
Edge
12–125Not supported
126+Supportedsince Jun 13, 2024
Current: 154
Firefox
1–148Not supported
149+Supportedsince Mar 24, 2026
Current: 157
Safari
✕Not supportedup to 27
Current: 27
MobileChrome Android
18–125Not supported
126+Supportedsince Jun 11, 2024
Current: 155
Firefox Android
4–148Not supported
149+Supportedsince Mar 24, 2026
Current: 157
Safari iOS
✕Not supportedup to 27
Current: 27

How to use

Not supported in Safari, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.

Example

Full syntax and examples are on MDN: CloseWatcher.

Feature detection

JS · check before using
if ("CloseWatcher" in globalThis) {
  // CloseWatcher is available
} else {
  // load a polyfill or use a fallback
}

Sub-features

Support for each part of the feature (7). The overall table above shows when the whole feature works.

Sub-featureChromeEdgeFirefoxSafariChrome AndroidFirefox AndroidSafari iOS
CloseWatcher126126149✕126149✕
CloseWatcher.CloseWatcher126126149✕126149✕
CloseWatcher.cancel_event126126149✕126149✕
CloseWatcher.close126126149✕126149✕
CloseWatcher.close_event126126149✕126149✕
CloseWatcher.destroy126126149✕126149✕
CloseWatcher.requestClose126126149✕126149✕