(development only) Extensions like Moesif CORS or Allow CORS can add the required headers on the fly — but never rely on this in production.
CORS is a browser-side security feature that restricts how a web page from one "origin" can request resources from a different "origin." An origin is defined by three things: (HTTP vs. HTTPS) Domain (example.com vs. example.com) Port (80 vs. 443) cors policy chrome
Vance sighed. "I believe you, kid. But my security protocols are strict. I can't just give data to anyone who asks. I need to know who you are." (development only) Extensions like Moesif CORS or Allow
When your frontend (e.g., localhost:3000 ) tries to call a backend API on another origin ( api.example.com ), Chrome requires the backend to explicitly allow that request using special HTTP headers like Access-Control-Allow-Origin . If those headers are missing or don’t match your frontend’s origin, Chrome blocks the request. example
: The browser (Chrome) adds an Origin header to the outgoing HTTP request, identifying where the request is coming from.