HTTP headers of a URL

What are HTTP headers for ?

Every web page returns invisible headers : the status code (200, 301, 404…), the server, cache handling, and above all the security headers (HSTS, CSP, X-Frame-Options). A good audit checks that they are present.

Frequently asked questions

What does a 301 or 302 code mean ?

They are redirects. A 301 is permanent (good for SEO), a 302 is temporary.