Here are some tools to help you view HTTP headers for web design or development.
Firefox is my first choice. Use the Live HTTP Headers extension.
If you are using an operating system like Linux, BSD, or Mac OS/X, you can use curl. First make sure that curl is installed by opening a terminal and typing
curl. If it isn’t installed and you are using Linux Mint, Ubuntu, or similar distro, type
sudo apt-get install curl to install it.
Once curl is installed, type
curl -I http://example.com/ to see the HTTP headers of the URL. Replace
http://example.com/ with the URL that you want to examine.
In Chrome or Chromium browsers, press F12 to open the developer console. Then click the network menu item and visit a webpage. Or install the HTTP Headers extension.