HTTP Header Parser

HTTP Header Parser
Enter a URL to fetch and analyze its HTTP response headers

About This Tool

HTTP Headers Parser helps developers inspect and understand the metadata sent by web servers in HTTP responses. Headers contain critical information about caching, security policies, content encoding, cookies, server configuration, and more. This tool fetches real HTTP headers from any URL and organizes them by category for easy analysis. Use it to debug API responses, audit security configurations, check CDN settings, troubleshoot caching issues, or learn about HTTP protocol mechanics. All parsing happens client-side for privacy, and results can be exported as JSON for documentation or further analysis.

How to Use

Enter a valid URL (must start with http:// or https://), then click 'Parse Headers' to fetch the response. View headers organized by category in the table view, or switch to JSON view for raw output. Copy or download headers for further analysis. The tool shows response status, timing, and categorizes headers into General, Security, Content, CORS, Caching, and other groups.

Common Use Cases

Security Audit

Check if a website has proper HSTS, CSP, and X-Frame-Options headers configured.

API Debugging

Inspect Content-Type, Content-Encoding, and custom API headers from backend responses.

Cache Analysis

Verify Cache-Control, ETag, and Expires headers to understand caching behavior.

CORS Troubleshooting

Check Access-Control-Allow-Origin and CORS-related headers for API integration issues.

Performance Check

Analyze compression headers and response timing.

Limitations & Important Notes

This tool fetches headers through a proxy API due to browser CORS restrictions—direct fetch from browser would be blocked by same-origin policy. Some websites may block requests from unknown user agents or IPs. Headers shown are from the proxy request, which may differ slightly from direct browser requests (User-Agent, Cookie headers won't match your browser). The tool cannot bypass authentication or access protected resources without proper credentials. Rate limiting applies to prevent abuse. For local development, use browser DevTools Network tab for more accurate headers.

Tips & Best Practices

**Status Codes**: 200-299 indicate success, 300-399 indicate redirects, 400-499 indicate client errors, 500-599 indicate server errors. **Security Headers**: Missing HSTS, CSP, or X-Frame-Options may indicate security vulnerabilities. **Caching**: Cache-Control and Expires headers determine how browsers and CDNs cache content. **Compression**: Content-Encoding: gzip or br indicates compressed responses for faster loading. **CORS**: Access-Control-Allow-Origin controls which domains can access the resource via JavaScript.