HTTP 413 Content Too Large — Request Entity Too Large Fix

When to Return 413

Typically configured at the server/proxy level (nginx client_max_body_size, Express bodyParser limit). Return 413 from application code when you enforce file size limits for uploads.

Common Causes

• File upload exceeding server limit
• JSON body larger than parser limit
• nginx client_max_body_size reached
• Attempting to upload video to an image-only endpoint

HTTP Response Example

HTTP/1.1 413 Content Too Large
Content-Type: application/json

{"error": "File too large. Maximum size is 5 MB."}

Code Examples

import multer from 'multer'

const upload = multer({
  limits: { fileSize: 5 * 1024 * 1024 }, // 5 MB
})

app.post('/upload', upload.single('file'), (req, res) => {
  res.json({ filename: req.file?.originalname })
})

// Multer error handler
app.use((err, req, res, next) => {
  if (err.code === 'LIMIT_FILE_SIZE') {
    return res.status(413).json({ error: 'File too large. Maximum size is 5 MB.' })
  }
  next(err)
})

// next.config.ts
export default {
  api: { bodyParser: { sizeLimit: '4mb' } }, // pages/ router
}

// App Router route handler
export const maxRequestBodySize = '4mb' // experimental

export async function POST(request: Request) {
  const formData = await request.formData()
  const file = formData.get('file') as File
  if (file.size > 5 * 1024 * 1024) {
    return Response.json({ error: 'File too large' }, { status: 413 })
  }
}

Related Status Codes