Free CORS Tester Online
Test Cross-Origin Resource Sharing configurations. Free, fast, and works entirely in your browser with no sign-up required.
CORS Tester & Debugger
Test CORS headers for any API endpoint and debug cross-origin issues.
CORS Tester
Frequently Asked Questions
What is the CORS Tester?
The CORS Tester is a free online tool that tests Cross-Origin Resource Sharing configurations to help you debug API access issues between different domains.
Is the CORS Tester free?
Yes, it is completely free with no registration required.
What is CORS?
CORS (Cross-Origin Resource Sharing) is a browser security feature that controls which domains can access your API. The CORS Tester helps you verify your configuration.
Is my data safe with this tool?
Absolutely. The CORS Tester processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the CORS Tester work on mobile devices?
Yes, the CORS Tester is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the CORS Tester in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
How do I use the CORS Tester?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
Which browsers are supported?
The CORS Tester works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.
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About Free CORS Tester Online
Free CORS Tester Online is a free, browser-based tool in our Security Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.