When a request is handled by Railgun, Cloudflare inserts a header with diagnostic information to track how the protocol is doing. Besides that , If you want to see these headers, you’ll need to use a browser that supports examining header information.

How to check with various browsers: 

Google Chrome: View > Developer > Developer Tools menu. You can also install Cloudflare’s Claire extension.

Safari: Develop > Show Web Inspector menu

Firefox: Install Firebug

Microsoft Internet Explorer: You can use a tool like Fiddler

cf-railgun:   e95b1c46e0 0.02 0.037872 0030 9878

cf-ray:   478149ad1570291

However , the CF-Railgun header has up to five codes separated by a space. In this order, from the example of cf-railgun, these codes and their corresponding values: e95b1c46e0 0.02 0.037872 0030 9878 are as follows:

• Railgun Request ID: e95b1c46e0 (internal process number that allows us to track what connection handled a request )
• Compression Ratio: 0.02 (the size of the response after Railgun’s delta compression expressed as a percentage)
• Origin Processing Time: 0.037872 (that Railgun waits for the origin web server to generate the page)
• Railgun Flags: 0030 (how a request was processed)
• Version Number: 9878 (indicates the version of the Railgun Listener software on the origin server’s network)