412 Precondition Failed

The HyperText Transfer Protocol (HTTP) 412 Precondition Failed client error response code indicates that access to the target resource has been denied. This happens with conditional requests on methods other than GET or HEAD when the condition defined by the If-Unmodified-Since or If-None-Match headers is not fulfilled. In that case, the request, usually an upload or a modification of a resource, cannot be made and this error response is sent back.

Status

412 Precondition Failed

Specifications

Browser compatibilityUpdate compatibility data on GitHub

The information below has been pulled from MDN's GitHub (https://github.com/mdn/browser-compat-data).

See also

• 304
• If-Unmodified-Since
• If-None-Match
• 428