You may have noticed that you cannot upload files to a server using Node.js and Express.js, despite trying various solutions. This article aims to provide a comprehensive guide to help you find a solution to this problem. If you tried many things but you didn't get good results so after reading this article you will get a great result. So below I described Multer a npm package that helps you a lot.

What is Multer?

The big question is what is multer? So basically Multer is a middleware used in Node.js to manage file uploads. It is made particularly to interact with Express.js, a well-liked Node.js web application framework. Multipart/form-data, the codec used for file uploads in HTML forms, is handled simply by Multer.

You may specify routes in your Express.js application that support file uploads using Multer. It handles processing the incoming request, retrieving the uploaded contents, and putting them in a designated spot on the server's filesystem or in cloud storage services like Amazon S3 or Google Cloud Storage.

How to use Multer in your Project?

I described some steps to use Multer in your project.

1. Install Multer as a dependency by running the following command in your project's directory:

npm install multer

1. Import Multer and configure it in your Express.js app file (app.js or index.js). Add the following code near the top of your file:

const multer = require('multer');
const upload = multer({ dest: './uploads' }); // Define the photos directory

1. Create a route in your Express.js app to handle the single file and multiple file uploads. For example, if you have a POST request to '/upload', use the following code:

// Below code for single file upload
app.post('/upload', upload.single('file'), (req, res) => {
  // Access the uploaded file using req.file
  // Process the file or perform any necessary operations
  // Send a response indicating success
  res.json({ message: 'File uploaded successfully!' });
});
// Below code for Multiple files upload
app.post('/upload', upload.array('file'), (req, res) => {
  // Access the uploaded files using req.file
  // Process the files or perform any necessary operations
  // Send a response indicating success
  res.json({ message: 'File uploaded successfully!' });
});

1. Finally, start your Express.js server and test the file upload functionality using a tool like Postman or by submitting a form with a file input field.

Make sure to customize the code based on your specific requirements and directory structure. You can check out Multer-NPM link for getting more information about Multer.

Conclusion

Using Multer you are able to upload any single or multiple files to the server without any error. Thank you for reading this blog.