When you see this status
- Uploading a file larger than server's max payload size
- Sending a request body exceeding configured limits
- POST/PUT request with body size beyond server threshold
Common causes
- Misconfigured server payload size limits
- Client sending unexpectedly large request body
- Network proxy or gateway enforcing size restrictions
How to debug it
- Check server configuration for max payload size
- Verify client request body size
- Inspect proxy/gateway size limits
- Split large payloads into smaller chunks
- Increase server's configured payload limit
Return this code in your framework
Express (Node.js)
app.post('/upload', (req, res) => { if (req.get('Content-Length') > 1048576) return res.status(413).send('Payload too large'); });
FastAPI (Python)
from fastapi import FastAPI, HTTPException; app = FastAPI(); @app.post('/upload'); async def upload(): raise HTTPException(status_code=413, detail='Payload too large')
NestJS
@Post('/upload') upload(@Body() data: any) { if (data.size > 1048576) throw new PayloadTooLargeException(); }
Go (net/http)
func handler(w http.ResponseWriter, r *http.Request) { if r.ContentLength > 1048576 { http.Error(w, "Payload too large", 413); return } }
About HTTP 413
HTTP status code 413 Payload Too Large is part of the
4xx Client Error family. Server refuses to process request because payload exceeds server limits. Understanding it is essential for
backend engineers, API designers, and anyone debugging integrations between services.
The Qaynaq Labs HTTP Status Code Explainer covers all standard codes with practical guidance:
what triggers them, how to debug them in production, and exactly how to return them from common
frameworks. Each code page is hand-curated and verified.