What are HTTP response headers?

Metadata a server returns alongside a page — security policies (HSTS, CSP), caching directives, content type, and the server stack.

Which security headers should I look for?

Strict-Transport-Security (HSTS), Content-Security-Policy, X-Content-Type-Options, and X-Frame-Options are common ones worth verifying.

HTTP Header Checker

Inspect the HTTP response headers a URL returns — security headers, caching, server, and more.

About this tool

Response headers reveal a lot: security policies (HSTS, CSP), caching, content type, and the server stack. Enter a URL to see exactly what it returns.

Frequently asked questions

What are HTTP response headers?: Metadata a server returns alongside a page — security policies (HSTS, CSP), caching directives, content type, and the server stack.
Which security headers should I look for?: Strict-Transport-Security (HSTS), Content-Security-Policy, X-Content-Type-Options, and X-Frame-Options are common ones worth verifying.