Precondition Required
HTTP 428 Precondition Required is a Client errors (4xx) status code. The server requires the request to be conditional to avoid lost updates.
What 428 means
The server requires the request to be conditional to avoid lost updates.
Prompts clients to send If-Match so two simultaneous updates do not silently overwrite each other.
Client errors (4xx)
The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Other 4xx codes
FAQ — 428
What does HTTP 428 mean?
428 Precondition Required: The server requires the request to be conditional to avoid lost updates. Prompts clients to send If-Match so two simultaneous updates do not silently overwrite each other.
Which class does status code 428 belong to?
428 is a Client errors (4xx) code. The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Where is the 428 code defined?
Status code 428 is defined in RFC 6585 and is part of the IANA HTTP Status Code Registry.