Security

What is CORS? CORS (Cross-Origin Resource Sharing) is a browser security mechanism that controls which websites can make API calls to other domains. What is an Origin? Origin = Protocol + Domain + Port https://example.com:443 ↑ ↑ ↑ Protocol Domain Port Same-Origin Examples: Origin 1: https://example.com/page1 Origin 2: https://example.com/page2 → Same origin ✓ Cross-Origin Examples: Origin 1: https://example.com Origin 2: https://api.example.com → Different domain = Cross-origin ✗ Origin 1: https://example.com Origin 2: http://example.com → Different protocol = Cross-origin ✗ Origin 1: https://example.com:443 Origin 2: https://example.com:8080 → Different port = Cross-origin ✗ Why CORS Exists Without CORS: ...