Allows web apps (as defined by the Web App Manifest standard) to set an app-wide badge in operating-system-specific places such as the shelf or home screen. Additionally, it gives the app a small, visible place to notify the user of new activity that might require attention, without showing a full notification. It can show additional information, such as an unread count or event type. It allows the app to convey this information when its windows are closed.
Documentation
Specification
Specification being incubated in a Community Group
Status in Chromium
Enabled by default
(tracking bug)
Consensus & Standardization
After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.
Owners
Intent to Prototype url
Intent to Prototype threadSearch tags
badge, notification, taskbar,Last updated on 2021-04-01
Comments
Shipped on Windows and macOS. Chrome OS support coming in (likely) 91. Android and Linux support are unlikely as those platforms don't have a native badge API.