npm i
npm start
# Now you can browse http://localhost on Chrome
# As of 29 April 2021, Chrome is the only major browser implementing UACH

1. The browser does the 1st request to http://localhost
2. The server answer with a Accept-CH response header, filled with checkboxes checked
3. Subsequent requests (for example style.css) are sent with the request headers asked from Accept-CH response header, in the previous request

• Check boxes to change Accept-CH response header value
• Click on the reload button to reload the page
• Headers are sent in GET query params, then parsed by the server, to minimise complexity and ease usability

Browsers

• Working on Chrome
• Not working on Brave
• Not working on Firefox

Combinations

• Emulating mobile devices gives different result: good to simulate how it works on mobile