📋 HTTP Header Checker
Inspect HTTP response headers for any URL. Review security headers, caching, content type, SEO-relevant headers, and raw server response.
Check Response Headers
About the HTTP Header Checker
This tool fetches the full HTTP response headers from any URL and categorizes them for easy review. HTTP headers control everything from caching, security, and content type to SEO directives and server identification.
Why HTTP Headers Matter
- Security — Missing HSTS, CSP, or X-Frame-Options headers leave your site vulnerable.
- SEO — X-Robots-Tag can block indexing; Link headers can specify canonicals for non-HTML files.
- Performance — Cache-Control and ETag headers enable browser caching, reducing load times.
- Debugging — Server and X-Powered-By headers reveal technology stack (sometimes sensitive).
Frequently Asked Questions
What are HTTP response headers?
HTTP headers are key-value pairs sent by the server along with every page response. They control caching, security, content type, and can even tell search engines not to index a page (X-Robots-Tag).
Which security headers should I look for?
Key security headers include Strict-Transport-Security (HSTS), X-Content-Type-Options (prevents MIME sniffing), X-Frame-Options (prevents clickjacking), Content-Security-Policy (CSP), and Referrer-Policy.
What is X-Robots-Tag?
X-Robots-Tag is an HTTP header that can control search engine indexing (noindex, nofollow) at the server level — useful for non-HTML files like PDFs. It works like the meta robots tag but via HTTP headers.