CORS Header Tester
Test CORS (Cross-Origin Resource Sharing) headers of any URL. Debug CORS issues.
Enter a URL to test CORS headers...
How to Use Cors Tester
- Enter the URL or data you want to check.
- Click the Check/Test button to analyze.
- Review the results and recommendations.
All processing happens locally in your browser. Your data is never uploaded to any server.
Frequently Asked Questions
Is Cors Tester free to use?
Yes, completely free. No signup, no limits. All processing happens in your browser — your data never leaves your device.
Does Cors Tester work on mobile?
Yes, it works on all devices including phones and tablets. The interface is fully responsive.
Is my data safe?
Absolutely. Everything runs locally in your browser using JavaScript. No data is uploaded to any server.