HTTP Indicator is a Chrome add-on developed by Rongjian Zhang. This free tool provides an indicator button that displays the HTTP/2, QUIC, and HTTP/3 support of each website you visit. With this extension, you can easily monitor the protocols being used by different websites.

The HTTP Indicator is a convenient alternative to HTTP/2 and SPDY indicators. It replaces the deprecated chrome.loadTimes() API with Navigation Timing 2, ensuring accurate and up-to-date information about the website protocols.

If you're interested in the technical details, you can check out the source code on GitHub. Overall, HTTP Indicator is a valuable tool for web developers, network administrators, or anyone who wants to stay informed about the protocols used by websites they visit.