I want installed PWAs to support an always-on-top window mode

I want installed Progressive Web Apps to be able to request an always-on-top window mode — either via the Web App Manifest or a JavaScript API — so that users can pin the PWA window above all other application windows on their desktop.

We are building video conferencing software as a PWA. One of the most-requested features from our users is the ability to keep the conference window visible while they navigate to other applications — just like native video calling apps (such as FaceTime or Google Meet on Android) that can float on top of everything else. Without an always-on-top capability, users have to manually arrange windows side-by-side, which is cumbersome and impossible on smaller screens.

Native desktop applications have long been able to request the "always on top" or "topmost" window flag from the operating system. Installed PWAs already benefit from many native-like capabilities through the Web App Manifest and APIs such as Window Management, but there is currently no way to achieve this specific behaviour.

A new display_override value (e.g., "always-on-top") in the manifest, or an opt-in JavaScript API that requires a user gesture and a permission prompt, would unlock this pattern while giving users control. This would make PWAs a viable replacement for native video conferencing, note-taking overlays, music players, and any other application where persistent visibility is a core part of the user experience.