Is CORS Header Tester free to use?

Yes, CORS Header Tester on DevHexLab is completely free. No login, no account, and no payment required.

Does CORS Header Tester upload my data to a server?

No. CORS Header Tester runs entirely in your browser using client-side JavaScript. Your data never leaves your device and is never sent to any server.

Can I use CORS Header Tester offline?

Yes. Once the page is loaded, CORS Header Tester works without an internet connection because all processing happens locally in your browser.

What category does CORS Header Tester belong to?

CORS Header Tester belongs to the "Network & API" category on DevHexLab. Test APIs, inspect headers, check DNS, and debug network issues

CORS Header Tester

Check what CORS headers a URL returns and debug cross-origin issues

corsheadersapicross-origindebug

CORS Test Configuration

Quick test:

Learn more

Step-by-step guide

How to Test CORS Configuration

Step-by-step guide to checking whether an API endpoint is configured to allow cross-origin requests using the DevHexLab CORS Tester.

In-depth article

CORS Explained: What It Is, Why It Exists, and How to Fix It

CORS errors are one of the most common headaches in web development. Learn exactly what Cross-Origin Resource Sharing is, why browsers enforce it, and how to configure it correctly.

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