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CORS Policy Tester

Simulate and validate Cross-Origin Resource Sharing (CORS) requests. Get instant feedback on header configurations and specific server setup guides for Nginx, Apache, and Node.js.

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aboutTool

CORS Policy Tester diagnoses and tests Cross-Origin Resource Sharing (CORS) configurations, a common pain point in API development. Simulate API calls from specific domains to verify header settings.

howToUse

  1. Enter the URL of the server you wish to test
  2. Configure your request method (GET, POST, etc.) and custom headers
  3. Click Send to see how the browser and server react to the security policy
  4. Review the suggested server-side fixes if the request fails

features

  • Real-time HTTP request simulation
  • Deep analysis of CORS violations and successes
  • Preflight (OPTIONS) request verification
  • Config snippets for Nginx, Apache, and Node.js
  • Customizable request headers
  • Clear error log tracking for debugging

faq

Is this an actual browser request?

Yes, it executes from your browser session to faithfully represent real-world CORS behavior.

Is wildcard (*) safe?

Using "*" is convenient but often insecure; we recommend explicit origin allow-lists for production.