View your browser request headers and explore common HTTP headers with descriptions. Free, fast, and private.
Click the button below to fetch your actual browser request headers via httpbin.org. This shows what your browser sends to servers.
HTTP headers are key-value pairs that accompany every request and response on the web, carrying metadata about the message: content type, caching directives, security policies, authentication tokens, encoding, and dozens of other concerns. Browsers, servers, CDNs, and intermediate proxies all read and write headers to coordinate behavior. Inspecting them is essential for diagnosing performance, caching, security, and integration issues.
This viewer fetches a URL and displays the response headers exactly as the server returned them. Common headers like Content-Type, Cache-Control, Content-Security-Policy, Strict-Transport-Security, and Set-Cookie are highlighted. The tool follows redirects by default, showing each step in the chain.
Some headers are particularly important for security and SEO. CSP (Content-Security-Policy) controls what resources a page can load. HSTS (Strict-Transport-Security) forces HTTPS. X-Frame-Options prevents clickjacking. Cache-Control influences how much traffic the server actually sees. Inspecting these on real responses helps verify configuration.
Most performance and security configuration on the web lives in headers rather than in HTML or JavaScript. CDN caching, browser caching, security policies, CORS, and HTTPS enforcement are all controlled by response headers. Inspecting actual responses confirms whether the configured headers are reaching clients.
Headers also help diagnose subtle bugs. A missing Content-Type triggers MIME sniffing. A wrong Cache-Control causes stale content or excessive load. A missing CSP allows unintended scripts. The viewer surfaces the actual headers so misconfigurations become visible.
Enter a URL, see all the response headers.
HTTP/1.1 (RFC 7230) defines headers as case-insensitive key-value pairs separated by colons, with the value continuing to the end of the line. HTTP/2 (RFC 7540) and HTTP/3 use a binary framing format internally but the header semantics remain the same; viewers display them as if HTTP/1 syntax for readability.
Common response headers: Content-Type (MIME type and charset), Content-Length, Content-Encoding (gzip, br for compression), Cache-Control, ETag, Last-Modified, Set-Cookie, Server, Date, X-Content-Type-Options, X-Frame-Options, Strict-Transport-Security, Content-Security-Policy.
The browser's same-origin policy may prevent JavaScript-based viewers from reading certain headers (cookies and authentication headers in particular). Proxy-based viewers (a server fetches and reports back) avoid this limitation.