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 HTTP endpoints, inspect request and response headers, perform DNS lookups, check IP geolocation, and encode URLs for safe transmission. These tools speed up API debugging and infrastructure troubleshooting without requiring any local installation.

CORS Header Tester

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

corsheadersapicross-origindebug

CORS Test Configuration

Quick test:

CORS Header Tester is coming soon

This tool is actively being built and will be available shortly. All other tools on DevHexLab are free and ready to use now.

Check back soon

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.

Related Tools

API Request Tester

Test HTTP API endpoints with custom headers and request body

HTTP Status Code Reference

Searchable reference for all HTTP status codes with explanations

HTTP Header Viewer

Inspect and decode HTTP request and response headers