CORS Test

Cross-Origin Resource Sharing configuration checker

CORS Test Tool Usage Guide

Main Features

  • Preflight Detection - Send OPTIONS request to test preflight
  • Header Parsing - Parse all Access-Control-* headers
  • Issue Diagnosis - Automatically detect CORS configuration issues
  • Fix Suggestions - Provide server-side configuration modification suggestions

What is CORS

  • CORS is the browser's cross-origin security policy mechanism
  • Cross-origin requests require servers to set correct response headers
  • Complex requests send a preflight OPTIONS request first
  • Credential requests require explicit Allow-Credentials