4xx Client Errors

HTTP 416 Range Not Satisfiable

The byte range requested cannot be fulfilled.

When is 416 used?

  • Requested file range exceeds file size
  • Invalid resume offset for downloads

How to handle a 416 response

Inspect the request — URL, method, headers, credentials, and body. Retrying the same request unchanged will usually fail again; 429 is the exception, where you should wait for the Retry-After period.

Check the status code a URL returns from the command line:

curl -s -o /dev/null -w "%{http_code}\n" https://example.com

How to return 416 from your server

Node.js (Express)

res.status(416).json({ message: 'Range Not Satisfiable' });

Python (Flask)

return {"message": "Range Not Satisfiable"}, 416

Go (net/http)

w.WriteHeader(416)

Frequently Asked Questions

What does HTTP 416 mean?

416 Range Not Satisfiable: The byte range requested cannot be fulfilled.

Is 416 an error?

Yes. 416 is in the 4xx Client Errors class. Client errors: the request is malformed, unauthorized, or targets something that does not exist.