Cannot access my backend from my frontend

I am trying to run a MERN application in the workspace. I have both the frontend and backend in the same workspace. My NodeJS server is running in port 4000 where as my React application is running in port 5173
and the mapped urls for both of them are as follows:

when trying to access the backend from the browser directly it does hit the server but when trying to hit the server using the frontend it responds with
Access to XMLHttpRequest at ‘backendurl’) from origin ‘frontendurl’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

and I have tried the steps from the docs as well

and have ran the following bash command
export port=4000

export API_SERVICE=“


still cannot access the server from the frontend

1 Like

Hi @NimAce,

Can you check my post about the same issue and confirm if you have the same result: Cors Issue?

I think your application has an Authorization token sent to its backend, is this correct? Also, your calls should include the withCredentials parameter (depending on what library you are using).

Looking forward to your feedback!

Thank you @Yel-kobi,
It did fix the issue. All I had to do was add

withCredentials: true,

Thank you for your help.

It works for get request but doesnt work with post request
Is there any thing I need to change for it too?

the server.js has

    origin: process.env.CLIENT_URL,
    credentials: true,
    methods: ["GET", "POST", "PUT", "DELETE"],
    allowedHeaders: ["Content-Type", "Authorization"],

and for the frontend I am using axios
as follows"/user/auth/login", data)

where API is

import axios from "axios";
const API = axios.create({
  withCredentials: true,
  baseURL: import.meta.env.VITE_API_URL,

export default API;

I am getting the same issue , above solution works for GET Method , but not working for POST method getting “preflight invalid allow credentials” cors error. Do you find any solution for this?

1 Like