Nginx 413 Request Entity Too Large Fix

A 413 response means a request body or upload is larger than a configured limit. Check every layer that receives the upload.

Symptoms

  • Uploads fail with 413.
  • Large JSON payloads fail while small requests work.
  • The app logs show nothing because Nginx rejects the request first.

Likely causes

  • client_max_body_size is too low.
  • PHP or app upload limits are smaller than Nginx limits.
  • CDN or reverse proxy has its own body-size limit.

Fix steps

  1. Set client_max_body_size in the correct http, server or location block.
  2. Align PHP post_max_size and upload_max_filesize when PHP receives the upload.
  3. Run nginx -t before reload.

Verify the fix

  • Test with a known file size.
  • Check response headers to confirm which layer returns 413.
  • Review Nginx error logs after the request.

FAQ

Where should client_max_body_size go?

Use the narrowest block that matches the upload endpoint unless the limit is site-wide.

Can PHP fix Nginx 413?

No, if Nginx rejects the request first. Both layers may need aligned limits.

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Last updated: May 18, 2026