What is CORS Tester?
CORS Tester is a free online tool that tests Cross-Origin Resource Sharing (CORS) configurations for APIs and web applications. It validates CORS headers, tests cross-origin requests, and helps identify configuration issues.
Built with modern web technologies, this tool operates entirely in your browser, allowing you to test CORS configurations without installing any software or browser extensions.
Why Use CORS Tester?
This tool eliminates the guesswork from CORS configuration. Test your API endpoints, validate CORS headers, and identify issues before deploying to production.
Perfect for web developers, API developers, DevOps engineers, and anyone working with cross-origin requests who needs to debug CORS policies quickly and reliably.
Common Use Cases
API Development: Test CORS configurations during API development and ensure proper header setup.
Debugging: Troubleshoot CORS errors in web applications and identify missing or incorrect headers.
Security Testing: Validate that CORS policies are properly configured to prevent unauthorized access.
Integration Testing: Test cross-origin requests before integrating third-party APIs or services.
How to Use CORS Tester
Enter the API endpoint URL you want to test and select the HTTP method (GET, POST, PUT, DELETE). Add any custom headers required for your request.
Click 'Test CORS' to send the request and view the CORS headers returned by the server. The tool will highlight any configuration issues and provide recommendations for fixing them.