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What is the App Badging API?
Short answer
The Badging API lets an installed PWA set a small numeric badge (or a plain dot) on its home-screen or taskbar icon, mirroring the unread-count badges native apps show. Call navigator.setAppBadge(count) to set it and navigator.clearAppBadge() to remove it — no argument shows a plain dot.
By InstantPWA engineering·Reviewed July 25, 2026
Where it works
Supported on Chromium desktop and Android, and on Windows, macOS and ChromeOS taskbars/docks for installed PWAs.
Typical use
Pairs with the service worker’s push event handler so an incoming push notification can also update the badge count.
Limits
Only works for installed apps, not open browser tabs, and iOS Safari does not support it as of 2026.
Sources
Related
Can a PWA send push notifications on iOS?
Yes. Since iOS 16.4 (March 2023), a PWA can send Web Push notifications on iPhone and iPad — but only after the user installs it to the home screen. Push in a regular Safari tab is not supported, and the user must explicitly grant notification permission from inside the installed PWA.
What is a PWA?
A PWA (Progressive Web App) is a regular website that meets three technical criteria — HTTPS, a Web App Manifest and a service worker — so browsers let visitors install it on their home screen. Once installed, it launches like a native app, works offline and can send push notifications.
What is the Web Share API?
The Web Share API lets a page call navigator.share({ title, text, url }) to open the operating system’s native share sheet, so users can send a link to Messages, Mail, social apps or any other installed share target — the same experience as sharing from a native app.
What is the Web Share Target API?
The Web Share Target API lets an installed PWA declare a share_target entry in its manifest so it shows up in the device’s share sheet as a destination — the same way Twitter or Google Photos appear when you tap "Share" from another app. The declared URL receives the shared title, text, url or files as a request.
What is the Screen Wake Lock API?
The Screen Wake Lock API lets a page request navigator.wakeLock.request("screen") to prevent the device screen from dimming or auto-locking while the page is active — useful for recipe apps being followed hands-free, presentation tools, or video calls. The lock automatically releases when the tab is hidden or closed.