Skip to content

4xx Client error

422 Unprocessable Content

The request is well-formed, but its content fails validation.

What 422 means

The JSON parses fine, but the values are wrong: a required field is empty, an email is invalid, a date is in the past. Popular in REST APIs (Rails, Laravel, FastAPI use it for validation errors).

Common causes

  • A field fails validation (wrong format, out of range, missing).
  • Business rules reject the data.

How to fix it

If you're calling an API

  • Read the error list in the body; it usually names each invalid field.

If you run the server

  • Return every validation error at once, with field names, so clients can fix them all.

Should you retry?

After fixing the data.

Example response

HTTP
HTTP/1.1 422 Unprocessable Content
Content-Type: application/problem+json

{
  "type": "about:blank",
  "title": "Unprocessable Content",
  "status": 422,
  "detail": "The request is well-formed, but its content fails validation."
}

Defined in: RFC 9110 (originally WebDAV). 422 is a client error: change the request before retrying.

Debugging an API call? Convert your request with the cURL converter, check the response with the JSON formatter, or see whether the API is down on its status page.

Often confused with

HTTP 422 FAQ

What does HTTP 422 mean?

422 Unprocessable Content: The request is well-formed, but its content fails validation. The JSON parses fine, but the values are wrong: a required field is empty, an email is invalid, a date is in the past. Popular in REST APIs (Rails, Laravel, FastAPI use it for validation errors).

Is 422 a client or server error?

It's a client error (4xx): something about the request needs to change before it can succeed.

How do I fix a 422 error?

Read the error list in the body; it usually names each invalid field.

Should I retry after a 422?

After fixing the data.

Other 4xx status codes

All HTTP status codes