412
Precondition Failed
Client errors (4xx)·RFC 9110
What 412 means
One of the conditions in the request headers was not met.
Used with conditional headers like If-Match to prevent lost updates when a resource changed since it was fetched.
Client errors (4xx)
The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Other 4xx codes
400Bad Request401Unauthorized402Payment Required403Forbidden404Not Found405Method Not Allowed406Not Acceptable407Proxy Authentication Required408Request Timeout409Conflict410Gone411Length Required413Content Too Large414URI Too Long415Unsupported Media Type416Range Not Satisfiable417Expectation Failed418I'm a teapot421Misdirected Request422Unprocessable Content423Locked424Failed Dependency425Too Early426Upgrade Required428Precondition Required429Too Many Requests431Request Header Fields Too Large451Unavailable For Legal Reasons
FAQ — 412
What does HTTP 412 mean?
412 Precondition Failed: One of the conditions in the request headers was not met. Used with conditional headers like If-Match to prevent lost updates when a resource changed since it was fetched.
Which class does status code 412 belong to?
412 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 412 code defined?
Status code 412 is defined in RFC 9110 and is part of the IANA HTTP Status Code Registry.