utilitybelt.dev
Sponsored

CORS Test

Test CORS headers and make cross-origin HTTP requests with custom methods and headers.

Custom Headers (one per line: Key: Value)

Sponsored

What is CORS Test?

The CORS Tester is a free, browser-based tool for developers who need to quickly test Cross-Origin Resource Sharing (CORS) headers on APIs and web services. Make custom HTTP requests with any method, headers, and body to verify your CORS configuration. No backend required—all requests are made directly from your browser. Perfect for debugging CORS issues, testing API endpoints, and validating server configurations.

Common Use Cases

  • Testing CORS headers on REST APIs
  • Debugging cross-origin request failures
  • Validating server CORS configurations
  • Testing preflight OPTIONS requests

Example: Input & Output

Sample Input

See the tool above for interactive examples.

Expected Output

The processed output will appear here instantly.

How to Use

  1. Step 1: Enter the API endpoint URL you want to test
  2. Step 2: Select the HTTP method (GET, POST, etc.)
  3. Step 3: Add any custom headers or request body if needed
  4. Step 4: Click 'Send Request' to execute the test
  5. Step 5: Review the response headers and body in the results panel

Frequently Asked Questions

Is this CORS tester free?

Yes, 100% free with no signup or account required.

Can I test CORS headers on any API?

Yes, as long as the API is publicly accessible and responds to cross-origin requests.

Why am I seeing CORS errors?

CORS errors occur when the server does not include the correct Access-Control-Allow-Origin headers in its response. Check the server's CORS configuration.

Can I test preflight OPTIONS requests?

Yes, select OPTIONS as the HTTP method and include any custom headers to simulate a preflight request.

Does this tool support authentication headers?

Yes, you can add any custom headers, including Authorization headers for Bearer tokens or API keys.

Privacy & Security

All data processing for the CORS Test happens entirely on your local machine within your browser. No data is ever sent to our servers, ensuring your information remains private and secure. We believe in privacy by design, and our tools are built to be used without compromising your data.