HTTP Header Checker
Enter any URL to see its HTTP response status and every header it returns — cache directives, security headers, cookies, server info, and more. Useful for debugging caching behavior, checking security headers like Content-Security-Policy, or seeing what a server reveals about itself.
Frequently asked questions
Why does the request go through your server instead of my browser?
Browsers block reading most response headers from a different origin unless that server explicitly allows it via CORS — that's what keeps one website from snooping on another's traffic. Fetching server-side sidesteps that restriction so you can inspect any public URL's real headers.
Why was my request rejected?
This tool blocks requests to localhost, private IP ranges (like 192.168.x.x or 10.x.x.x), and internal hostnames as a safety measure, since it's a publicly accessible tool that could otherwise be used to probe internal networks.