CORS Preflight Response Invalid HTTP Status Code 405 on OPTIONS Verb
A 405 Method Not Allowed specifically on the automatic OPTIONS preflight request means your server (or a framework/router within it) has no route configured to...
Search
21 results for "CORS"
CORS Error Despite Headers Present (Preflight OPTIONS Request Failing)
When your actual API endpoint clearly returns correct CORS headers, but the browser still blocks the request with a CORS error, the real problem is almost...
Nginx CORS Header "Multiple Values" Received Error
The browser error about receiving multiple values for a CORS header means both Nginx and your backend application are independently setting the same...
CORS vs CSRF, What's the Actual Difference
CORS and CSRF get confused constantly because they both involve cross-origin requests and both show up in the same part of the stack — but they solve...
Flask CORS Blocking Requests From Local Network IP
A Flask API that works fine when accessed from localhost but gets blocked by CORS when accessed from another device on the local network (like a phone testing...
Gin CORS Error Blocking React Native Requests
A CORS error between a React Native app and a Gin backend is technically a browser-enforced restriction, but it commonly shows up during development with tools...
How to Fix "Gin Error: c.JSON() Not Sending Response Headers"
You call c.JSON() in a Gin handler expecting custom headers (CORS, cache-control, auth tokens) to reach the client, but they're missing from the actual HTTP...
How to Fix "401 Unauthorized" with Bearer Token Header in API
Receiving an HTTP 401 Unauthorized status code when passing an Authorization: Bearer <token> header is a common hurdle in API integration. This response...
Nginx "Upstream Sent Too Big Header While Reading Response Header From Upstream"
This error means the response headers sent by your backend exceed the buffer size Nginx has allocated to hold them — Nginx's default buffer sizes are...