About
CORS Tester is a web-based tool for checking Cross-Origin Resource Sharing behavior against an API endpoint. It accepts an API URL, origin, HTTP method, optional credentials, custom headers, and request body, then returns preflight response headers and API server response headers for review.
The tool is aimed at developers and API testers who need to debug CORS errors, verify allowed methods and headers, and confirm credential handling. The page also includes a CORS support checklist covering OPTIONS responses, Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, Access-Control-Allow-Credentials, and Access-Control-Max-Age.
- API URL and origin testing
- OPTIONS preflight response inspection
- Custom headers and request body
- Credentialed request support
- CORS error checklist
- Access-Control-Max-Age guidance
Free Tier Value
This free tier appears to be a perpetual, uncapped public tool with no signup or credit card friction, so it scores above a token free sample. Because there is no paid plan shown to anchor against, the practical value is estimated at about $2/month for a small but genuinely usable developer utility.
What's included in the free tier
- Access to the CORS Tester tool for checking CORS headers and debugging CORS errors.
- Ability to enter an API URL, origin, method, credentials, custom headers, and custom body for tests.
- Ability to test preflight OPTIONS responses and view request/response headers.
- Ability to share a CORS test with API URL, origin, and method included.
See CORS Tester pricing for current limits.