How to Use the HTTP Header Checker

What the tool does

HTTP headers are notes a web server attaches to every answer: what kind of content it sent, how long it may be kept, which software answered, and instructions for the browser. The tool requests the address from our server, follows any redirects, and shows the headers of the final answer.

How to use it

1. Type a web address, such as example.com, and press Show headers.
2. Read the summary, then the At a glance lines: status, content type, server, caching, compression and how long it took.
3. Open the security headers and the full table for the technical detail.

A worked example

After the summary you see six common security headers, then every header in a table. A security header that is not sent is shown as information, never as a fault. Whether a site needs a given header depends on the site, so nothing here calls a site unsafe. Cookie values are never shown, only the cookie names.

Things to know

• These are the headers our server received once. A browser, a search engine or a visitor elsewhere can receive different ones.
• Only the final address after redirects is shown in the table. Use the Redirect Checker for each step.
• The address you enter is sent to our server, which requests it and discards the page. We do not keep the address or a history.

Common questions

Why does a missing security header not count as a fault? Because what a site needs depends on the site. The tool reports what it sees and leaves the judgment to you.

Can I check a private or local address? No. Only public websites can be checked.

HTTP Header Checker: Open the HTTP Header Checker and try your own numbers.