I've installed FireBug, but I am not sure how to find out if a certain http header is present in my HTTP response. Where should I look for this information?
Use the Net tab in Firebug to monitor network traffic. There you can see the complete headers as well as the timing and content of any network/HTTP queries.
Looks like this:
Fiddler is the best tool I know of to do this and much more, including inspecting the entire request/response in many formats including a nice XML browser.
Fiddler in good but sometimes it causes problems because of changing the system proxy configuration.
Check the HTTP Debugger, it's not a proxy and doesn't create such problems https://www.httpdebugger.com
来源：https://stackoverflow.com/questions/5374100/how-to-debug-the-http-response-headers-from-a-http-call