Launch handlerLimited availability
The launch_handler web app manifest member, with the client_mode property, configure how web app launches behave when an instance of the app is already open. For example, you can choose to focus the existing app instance instead of launching a new one.
Not yet supported in all major browsers — check the table and provide a fallback.
Browser support
DesktopChrome
1–109Not supported
110+Supportedsince Feb 7, 2023
Current: 155Edge
12–109Not supported
110+Supportedsince Feb 9, 2023
Current: 154Firefox
✕Not supportedup to 157
Current: 157Safari
✕Not supportedup to 27
Current: 27MobileChrome Android
✕Not supportedup to 155
Current: 155Firefox Android
✕Not supportedup to 157
Current: 157Safari iOS
✕Not supportedup to 27
Current: 27How to use
Not supported in Firefox, Safari, Chrome Android, Firefox Android, Safari iOS. Use feature detection below and provide a fallback (or a polyfill) for those browsers.
Example
Full syntax and examples are on MDN: LaunchParams.
Feature detection
JS · check before using
if ("LaunchParams" in globalThis) {
// LaunchParams is available
} else {
// load a polyfill or use a fallback
}Specification
Sub-features
Support for each part of the feature (7). The overall table above shows when the whole feature works.
| Sub-feature | Chrome | Edge | Firefox | Safari | Chrome Android | Firefox Android | Safari iOS |
|---|---|---|---|---|---|---|---|
| LaunchParams | 102 | 102 | ✕ | ✕ | ✕ | ✕ | ✕ |
| LaunchParams.targetURL | 110 | 110 | ✕ | ✕ | ✕ | ✕ | ✕ |
| LaunchQueue | 102 | 102 | ✕ | ✕ | ✕ | ✕ | ✕ |
| LaunchQueue.setConsumer | 102 | 102 | ✕ | ✕ | ✕ | ✕ | ✕ |
| Window.launchQueue | 102 | 102 | ✕ | ✕ | ✕ | ✕ | ✕ |
| manifests.webapp.launch_handler | 110 | 110 | ✕ | ✕ | 110 | ✕ | ✕ |
| manifests.webapp.launch_handler.client_mode | 110 | 110 | ✕ | ✕ | 110 | ✕ | ✕ |