Years of first stable shipment. Open circles mean "still not shipped, as of May 2026". For Safari I use the iOS Safari date where it differs from macOS, since iOS is where the PWA story is constrained. Click any API name to open its MDN reference (includes the live browser support matrix).
Sources: caniuse, MDN, vendor release notes. Web Serial in Firefox is Nightly only as of May 2026, drawn as 2026. Safari Push/Notifications/Badging dates are iOS 16.4 (March 2023), when Safari first allowed installed home-screen PWAs to use them.