Node.js Express File Upload

Handle file uploads in Node.js Express using multer middleware with disk and memory storage strategies, file filtering by MIME type, size limits, and.

Javascript Node File Upload Updated: 2026-01-15

Code

snippet

import multer from 'multer';

const storage = multer.diskStorage({
  destination: (req, file, cb) => cb(null, 'uploads/'),
  filename: (req, file, cb) => cb(null, `${Date.now()}-${file.originalname}`),
});

const upload = multer({
  storage,
  limits: { fileSize: 10 * 1024 * 1024 },
  fileFilter: (req, file, cb) => {
    const allowed = ['image/png', 'image/jpeg', 'application/pdf'];
    cb(null, allowed.includes(file.mimetype));
  },
});

app.post('/upload', upload.single('file'), (req, res) => {
  res.json({ path: req.file.path, size: req.file.size });
});