View all HTTP headers sent by your browser with our free HTTP headers viewer tool. This header checker shows request headers, user agent information, cookies, referrer data, and other metadata transmitted with every web request. Perfect for debugging, testing APIs, verifying proxy configurations, and understanding what information your browser sends to websites.
HTTP headers are metadata fields sent with every web request and response.
This shows the exact headers your browser sent on this request — including proxy/CDN headers like X-Forwarded-For if you're behind one. It's the same data a server-side script would see, useful for debugging why a server is behaving differently than expected for your connection.
Custom headers typically start with "X-" by convention, though modern standards prefer using standard headers or defining new ones properly. View these headers to verify they're being sent correctly by your application.