File uploads are a core feature in most modern web applications — whether it’s profile pictures, product images, documents, or CSV imports. Express.js doesn’t handle multipart/form-data out of the box, which is why we need Multer . This is your one-stop, brain-friendly guide to mastering file uploads with Multer. Why Do We Need Middleware for File Uploads? HTML forms with enctype="multipart/form-data" send data differently from regular application/x-www-form-urlencoded forms. Text fields → easy Files → binary data + metadata Node.js/Express req.body and req.query can’t parse this format natively. That’s where Multer comes in — it parses the multipart request, extracts files and fields, and attaches them to the request object ( req.file / req.files ). Simple Analogy : Think of Multer as a helpful receptionist who opens the package (multipart request), sorts the documents (text fields) and gifts (files), and hands them to you in an organized way. What is Multer?…