422 Unprocessable Content
The server understands the content type and syntax but cannot process the contained instructions.
| Class | Client error (4xx) |
|---|---|
| Defined in | RFC9110, Section 15.5.21 |
| Cacheable by default | No, unless explicit freshness headers allow it |
Common causes
- JSON that is well-formed but fails validation, such as a missing required field.
- Business rules rejecting the data.
What to do
Return details about which fields are invalid so the client can correct them. Its official name is now 'Unprocessable Content'.
Related codes
- 400 Bad Request: The server cannot process the request because it looks malformed.
- 409 Conflict: The request conflicts with the current state of the resource.
- 415 Unsupported Media Type: The server refuses the request because the body's media type is not supported.