HTTP Header & CORS Tester
Test HTTP headers, check CORS configuration, and analyze security headers.
Test HTTP headers, check CORS configuration, and analyze security headers for any website.
Cross-Origin Resource Sharing (CORS) is a security feature implemented by browsers.
Key headers:
Access-Control-Allow-OriginAccess-Control-Allow-MethodsAccess-Control-Allow-Headers
Strict-Transport-Security: Forces HTTPS connections
Content-Security-Policy: Prevents XSS attacks
X-Frame-Options: Prevents clickjacking
X-Content-Type-Options: Prevents MIME sniffing
This tool runs in your browser and is subject to CORS restrictions.
What works: Testing your own domains, CORS-enabled APIs (like GitHub API)
What doesn't work: Testing third-party sites that don't allow CORS
Pro version: Uses server-side proxy to test any URL without CORS limitations
✨ Test any URL without CORS restrictions (server-side)
✨ Full request/response analysis including body
✨ Custom request headers and methods
✨ Certificate and TLS/SSL analysis
✨ Performance waterfall and timing breakdown
✨ Historical tracking and monitoring
✨ Automated security header recommendations
✨ Batch testing for multiple URLs
About This Tool
This tool processes all data locally in your browser for maximum privacy and security. No data is sent to any server.