The default port for ng serve, the Angular development server.
Angular CLI's serve builder defaults to port 4200, so any machine doing Angular frontend work has one. IANA assigns the 4200-4299 range to vrml-multi-use, which you will not encounter. A 4200 on a scan is a developer workstation or a container that shipped a dev build instead of a production bundle.
Do not expose
It is an unauthenticated dev server with a live-reload websocket and unminified sources — keep it on localhost.
$ curl -s http://localhost:4200/ | head -20Seen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
Get Beige Box →also available as JSON · Markdown
Corrections or a missing port? Reply @rimrocksystems.