HTTP Header Analyzer
Fetch HTTP response headers from any URL or paste raw headers from curl / browser DevTools. Get a parsed breakdown with explanations, security audit, caching analysis, and CORS checks.
Uses a HEAD request via the Fetch API. Due to browser CORS restrictions, only headers from CORS-enabled URLs will be visible. For full headers, use curl -I <url> and paste the output below.
About HTTP Header Analyzer
HTTP headers carry metadata about requests and responses between clients and servers. They control caching, security, authentication, content negotiation, and more. Misconfigured headers can lead to security vulnerabilities, poor performance, or broken CORS.
This tool parses raw headers, categorizes each one, explains what it does, and runs automated audits for security best practices, caching efficiency, and cross-origin resource sharing configuration.
Features
- Parse raw HTTP headers from curl, browser DevTools, or any source
- Structured table with header name, value, category, and explanation
- Click any header name to see full documentation and examples
- Security audit: checks for CSP, HSTS, X-Frame-Options, X-Content-Type-Options, and more
- Caching analysis: interprets Cache-Control directives, Expires, ETag, Last-Modified
- CORS analysis: explains Access-Control-* header configuration
- Color-coded severity: green (good), yellow (warning), red (missing/bad)
- Pre-built example header sets for common scenarios
- Copy parsed results to clipboard
- 100% client-side — your data never leaves your browser