CORS Tester
NewAnalyze CORS (Cross-Origin Resource Sharing) configuration by parsing Access-Control-* response headers. Enter the headers returned by a server to check: allowed origins (Access-Control-Allow-Origin), allowed methods, allowed headers, credentials support (Access-Control-Allow-Credentials), and preflight cache duration (Access-Control-Max-Age). Identifies overly permissive CORS policies (wildcard with credentials) and explains the security implications.
CORS Tester
Simulate CORS origin validation. Check if a requesting origin would be allowed by your CORS policy.
Origin "https://example.com" would be ALLOWED
How to Use CORS Tester
- 1Paste the CORS response headers
- 2View analysis of each CORS directive
- 3Check for security issues
- 4Read remediation recommendations
Your Privacy is Protected
CORS Tester runs entirely in your browser. Your files and data are never uploaded to any server, never stored, and never shared. Everything happens locally on your device using secure browser APIs.
Frequently Asked Questions
What is the CORS vulnerability with credentials?
Setting Access-Control-Allow-Origin: * with Access-Control-Allow-Credentials: true is not allowed by browsers, but misconfigured APIs that echo the Origin header can create security issues.
Why Use This Tool?
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