Complete HTTP status code reference with descriptions. Search all 1xx, 2xx, 3xx, 4xx, and 5xx status codes with explanations
A quick reference for every HTTP status code. Look up any code from 100 to 599, see what it means, when servers return it, and how to handle it in your application.
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Your API returns a 422 and a teammate insists "that is not a real status code." You want the authoritative meaning and when to use it.
Looked up
422
Reference entry
422 Unprocessable Entity (RFC 4918) Class: 4xx, Client Error The request was well-formed but failed semantic validation (e.g. valid JSON, but "email" is missing or malformed). Retry without changes: No, fix the payload first.
422 is a real, registered status from the WebDAV spec that REST APIs widely reuse for validation failures, distinct from 400 (malformed syntax the server could not parse) and 409 (a state conflict). Knowing the class (4xx = caller must change something, 5xx = server problem) tells you immediately whether retrying the identical request can ever succeed.
A quick reference for every HTTP status code. Look up any code from 100 to 599, see what it means, when servers return it, and how to handle it in your application.
401 means the request lacks valid authentication credentials. 403 means the server understood who you are but you're not allowed to access the resource.
Use 404 when a resource is not found but might exist later. 410 signals the resource existed once but has been permanently removed.
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