Screen Recorder (Display Capture)
Requires HTTPS or http://localhost. Allow screen share when prompted. System audio is optional in the picker.
Tip: To record system audio, check “Share system audio” (or similar) in the screen picker dialog. Not all OS/browser combos support it.
Offline: Service workers must be served from a separate JS file over HTTPS/localhost. This single-file demo includes the SW code below, and also a “Save service-worker.js” button so you can export it next to this HTML file and reload to enable offline caching.