PWA is the more common of the two in our index: it runs on 11,683 websites against 11 for WebSocket, and 6 sites use both. Counts come from real scans, not vendor claims.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
WebSocket is a communication protocol that provides full-duplex communication channels over a single, long-lived connection, enabling interactive communication between web browsers and servers.
6 sites run both PWA and WebSocket. That is 55% of the sites using WebSocket, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.