416

Range Not Satisfiable

4xx Client Error

Back to list.md

ELI5

You asked for a specific part of a file (like pages 50-60), but the file only has 10 pages. I can't give you what doesn't exist.

Server perspective

Use 416 when a supported Range request is syntactically valid but unsatisfiable for the selected representation.

When to use

•Return 416 when the requested byte range falls outside the current representation length
•Use it only when range handling is relevant for the target resource
•Range request beyond file size
•Invalid byte range specifications
•Start position greater than file length
•Malformed Range headers

How to respond

•Include Content-Range in the form bytes */<complete-length>
•Expose Accept-Ranges when you want clients to know range requests are supported

Headers to consider

•Content-Range
•Accept-Ranges

Response body

•Include Content-Range with the current representation length when possible so the client can correct its range.

Server-side pitfalls

•Do not use 416 when there was no meaningful Range request to evaluate
•Do not omit the complete length when it is available
•Valid range requests (use 206 Partial Content)
•No Range header provided (use 200 OK)
•Server doesn't support ranges (use 200 OK)

Examples

Range beyond file size

Request:

GET https://api.example.test/video.mp4

# Headers
Range: bytes=100000000-200000000

Response:

416 Range Not Satisfiable

# Headers
Content-Range: bytes */50000000
Content-Type: application/json

# Body
{
  "error": "range_not_satisfiable"
}

Requested range starts beyond the 50MB file size

References

Related Status Codes

Partial Content

You asked for just a piece of a file (like pages 5-10 of a book), and here's that specific piece you wanted!

OK

Everything worked perfectly! The server understood your request and sent back exactly what you asked for.