How to determine if the site uses http2 (chrome)

By using natively availableperformance APIs:

window
.performance
.getEntriesByType("resource")
.filter(p => 'nextHopProtocol' in p)[0]
.nextHopProtocol // 'h2'

By using the deprecated loadTimesAPI:

window.chrome.loadTimes().wasFetchedViaSpdy; // true window.chrome.loadTimes().npnNegotiatedProtocol; // 'h2' window.chrome.loadTimes().connectionInfo; // 'h2'

The deprecation notice can be read here: https://chromestatus.com/feature/5637885046816768

Feature Flag

If you’re in an older machine OR browser, then go to chrome://net-internals/#http2 and open the network observation component, and select HTTP/2

View gist: https://bigfatsoftwareinc.wordpress.com/2022/04/16/how-to-determine-if-the-site-uses-http2-chrome/

Originally published at http://bigfatsoftwareinc.wordpress.com on April 16, 2022.