Cross-Origin Resource Sharing (CORS) is a security feature of the modern web that prevents websites from making requests across different domains. In Node.js, you can fix CORS issues by using middleware libraries like cors.
Here's an example of how to use cors in your Express.js application:
- First, install the
corspackage if you haven't already:
npm install cors
- Then, require and use it in your server file (e.g.,
server.js) like this:
const express = require('express');
const cors = require('cors');
const app = express();
app.use(cors());
// Your routes go here...
app.listen(3000, () => {
console.log('Server is running on port 3000');
});
If you need to customize the CORS behavior, you can pass an options object to cors():
const cors = require('cors');
app.use(cors({
origin: 'http://example.com', // Allow requests from this origin only
methods: ['GET', 'POST'], // Allow these methods only
allowedHeaders: ['Content-Type'] // Allow these headers only
}));
If you want to allow all origins (not recommended in production), you can use '*' as the value for origin.
That's it! With this setup, your Express.js application will be CORS-compliant and will handle requests from any origin by default.