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Jamsheer Ali
Jamsheer Ali

Posted on • Originally published at dnsfly.net

How to Read HTTP Headers

Every website sends hidden information with every page load. HTTP headers control security, caching, redirects, and more — here's how to read them and what to look for

What Are HTTP Headers?

When you visit a website, your browser sends a request to the server, and the server sends back a response. Both the request and the response include headers — metadata that tells each side how to handle the communication.

Think of it like sending a package. The package itself is the web page content (HTML, images, CSS). The headers are the shipping label — they don't contain the content, but they tell the carrier where it's going, how to handle it, and what's inside.

The Headers That Matter Most

There are dozens of possible HTTP headers, but most of the time you only need to care about a handful. Here are the ones you'll see most often.

  • content-type
  • server
  • cache-control
  • location
  • set-cookie
  • content-encoding
  • x-powered-by

Security Headers You Should Check

  • Strict-Transport-Security (HSTS)
  • X-Frame-Options
  • X-Content-Type-Options
  • Referrer-Policy
  • Permissions-Policy

How to Check HTTP Headers

1.DNSFly HTTP Headers Tool
2.Browser DevTools
3.Command Line

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