Fix Next.js Error: fetch failed due to Network or CORS Issues (2025 Guide)

Posted on: April 9, 2025

Encountered an "Error: fetch failed due to Network or CORS Issues" in Next.js? This error occurs when a `fetch` request fails due to network problems or CORS policy violations. Let’s fix it fast in this 2025 guide!

What Causes "Error: fetch failed due to Network or CORS Issues"?

This error occurs when a `fetch` request in Next.js fails due to network or CORS issues. Common causes include:

• Network Failure: The API endpoint is down or unreachable.
• CORS Policy Violation: The server doesn’t allow cross-origin requests.
• Invalid Endpoint: The API URL is incorrect or misconfigured.

Here’s a Next.js example that triggers the error:

export async function getServerSideProps() {
  // This will trigger "Error: fetch failed"
  const res = await fetch('https://invalid-api-endpoint.com/data');
  const data = await res.json();
  return { props: { data } };
}

export default function Page({ data }) {
  return 
Data: {data}
;
}

Running this in Next.js will throw the error if the endpoint is invalid or CORS is not configured.

For a simpler demo of a failed fetch, check this simulation (open console with F12):

How to Fix It: 3 Solutions

Let’s resolve this error with practical steps:

(Diagram: Developer makes fetch request, gets error, fixes CORS, fetches successfully.)

Solution 1: Configure CORS on the Server

Ensure the API server allows cross-origin requests by setting CORS headers:

// Example: Node.js/Express server
const express = require('express');
const cors = require('cors');
const app = express();

app.use(cors()); // Enable CORS for all routes

app.get('/data', (req, res) => {
  res.json({ message: 'Hello from API' });
});

app.listen(3000, () => console.log('Server running on port 3000'));

Adding CORS headers on the server allows your Next.js app to fetch data without restrictions.

Solution 2: Use a Proxy in Next.js

Set up a proxy in Next.js to bypass CORS issues by routing requests through your server:

// next.config.js
module.exports = {
  async rewrites() {
    return [
      {
        source: '/api/:path*',
        destination: 'https://external-api.com/:path*', // Proxy to external API
      },
    ];
  },
};

// getServerSideProps
export async function getServerSideProps() {
  try {
    const res = await fetch('http://localhost:3000/api/data');
    const data = await res.json();
    return { props: { data } };
  } catch (err) {
    return { props: { error: err.message } };
  }
}

export default function Page({ data, error }) {
  if (error) return 
Error: {error}
;
  return 
Data: {data}
;
}

Using a proxy routes requests through your Next.js server, avoiding CORS issues.

Solution 3: Add Error Handling for Network Issues

Handle network errors gracefully with `try-catch` and validate the API response:

export async function getServerSideProps() {
  try {
    const res = await fetch('https://invalid-api-endpoint.com/data');
    if (!res.ok) throw new Error('Network error: Failed to fetch data');
    const data = await res.json();
    return { props: { data } };
  } catch (err) {
    return { props: { error: err.message } };
  }
}

export default function Page({ data, error }) {
  if (error) return 
Error: {error}
;
  return 
Data: {data}
;
}

Proper error handling ensures your app doesn’t crash on network failures.

Quick Checklist

• CORS issue? (Configure CORS on the server)
• Cross-origin restrictions? (Use a proxy in Next.js)
• Network failure? (Add error handling)

Conclusion

The "Error: fetch failed due to Network or CORS Issues" in Next.js can be resolved by configuring CORS, using a proxy, and handling errors. With these 2025 solutions, your data fetching will stay reliable. Got another Next.js error? Let us know in the comments!