HTTP Header Analyzer
Paste or retrieve HTTP response headers to organize important fields and understand how a browser or crawler may handle the response.
How to Use HTTP Header Analyzer
- Provide the response headers exactly as returned, keeping one header per line.
- Analyze the block and review content, caching, redirect, and policy fields.
- Compare unexpected values with the web server, application, proxy, and CDN configuration that can each modify headers.
What Response Headers Control
HTTP headers carry metadata outside the response body. Content-Type describes the representation, Cache-Control guides caches, Location provides a redirect target, and policies such as Content-Security-Policy affect browser behavior.
Interpret related headers together. For example, a long cache lifetime may be appropriate for versioned assets but harmful for frequently changing HTML. Duplicate or proxy-added headers can also produce behavior that differs across hops.
HTTP Header Analyzer Example
Analyzing `Cache-Control: public, max-age=31536000, immutable` shows a one-year cache policy suited to a fingerprinted asset, not normally to an unversioned homepage.
Frequently Asked Questions About HTTP Header Analyzer
Are HTTP headers case-sensitive?
Header field names are case-insensitive, although their values follow rules specific to each header.
Why do browser headers differ from an origin-server test?
A CDN, reverse proxy, hosting layer, service worker, or browser cache can add, remove, or reuse headers.
Does a security header prove that a site is secure?
No. Headers can reduce specific browser risks, but they do not audit application code, authentication, dependencies, or infrastructure.