The HyperText Transfer Protocol (HTTP) 501 Not Implemented server error response code indicates that the request method is not supported by the server and cannot be handled. The only methods that servers are required to support (and therefore that must not return this code) are GET and HEAD.

Notes:

  • A 501 error is not something you can fix, but requires a fix by the web server you are trying to access.
  • A 501 response is cacheable by default.

Status

501 Not Implemented

Specifications

Specification Title
RFC 7231, section 6.6.2: 501 Not Implemented Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

Browser compatibility

The information shown 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

Document Tags and Contributors

Contributors to this page: RayannTedds, haroldfredshort, fscholz, Jeremie
Last updated by: RayannTedds,