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

Specification Title
RFC 7232, section 4.2: 412 Precondition Failed Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests

Browser compatibility

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

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes Yes Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes Yes Yes Yes Yes

See also

Document Tags and Contributors

Last updated by: RayannTedds,