IT & Developers
CORS Headers Generator - Generate CORS configuration for different servers
Generate CORS configuration for different servers
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
Frequently asked questions
What is CORS?
Cross-Origin Resource Sharing - browser security feature controlling cross-domain requests.
Why can't I use * with credentials?
Spec prohibits Access-Control-Allow-Origin: * when credentials are included. Must specify exact origin.
What is preflight?
OPTIONS request sent before actual request for non-simple requests. Max-Age caches this.
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About this tool
This CORS Headers Generator turns your inputs into practical results. Provide Preflight Cache (seconds), Allowed Origins, and Allowed Methods to calculate CORS Headers and Server Configuration.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.