How do you test a website for http2 protocol?

There are several ways to test a website for HTTP/2 protocol support:

Using Browser Developer Tools:

• Chrome:
  1. Open the website in Chrome.
  2. Press F12 to open the Developer Tools.
  3. Go to the “Network” tab.
  4. Enable the “Protocol” column by right-clicking anywhere on the table header and selecting “Show columns” -> “Protocol”.
  5. Reload the page. You will see which resources are using HTTP/2 in the “Protocol” column.
  6. Additionally, a blue lightning bolt icon appears near the search bar if the entire page is loaded over HTTP/2.
• Firefox:
  1. Open the website in Firefox.
  2. Press F12 to open the Developer Tools.
  3. Go to the “Network” tab.
  4. Right-click anywhere on the table header and select “Add column” -> “Protocol”.
  5. Reload the page. You will see which resources are using HTTP/2 in the “Protocol” column.

Using Online Tools:

• KeyCDN HTTP/2 Test: https://www.keycdn.com/blog/keycdn-http2-support
• CDNsun HTTP/2 Support Test: https://www.keycdn.com/blog/http2-cdn
• Site24x7 HTTP/2 Checker: https://support.site24x7.com/portal/en/kb/articles/can-i-monitor-websites-that-requires-http-post-to-determine-availability

Using Command Line Tools:

• cURL: Download the latest version of cURL and run the following command: curl --http2 <website_url>
• OpenSSL: Make sure OpenSSL is built with ALPN support and run: openssl s_client -alpn h2 -connect <website_url>:<port> -status

Using Browser Extensions:

• HTTP/2 and SPDY Indicator (Chrome): https://chrome.google.com/webstore/detail/http-indicator/hgcomhbcacfkpffiphlmnlhpppcjgmbl
• HTTP/2 Indicator (Firefox): https://addons.mozilla.org/en-US/firefox/addon/http2-indicator/

Remember, HTTP/2 requires HTTPS encryption, so make sure the website uses HTTPS before testing.