401 Unauthorized

The HyperText Transfer Protocol (HTTP) 401 Unauthorized client error status response code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource.

This error status is sent with an HTTP WWW-Authenticate response header that contains information on how the client can request for the resource again after prompting the user for authentication credentials.

This error status is similar to the 403 Forbidden error status, except that in situations resulting in this error status, user authentication can allow access to the resource.

Status

401 Unauthorized

Example response

HTTP/1.1 401 Unauthorized
Date: Wed, 21 Oct 2015 07:28:00 GMT
WWW-Authenticate: Basic realm="Access to staging site"

Specifications

Specification
Hypertext Transfer Protocol (HTTP/1.1): Authentication (HTTP/1.1)
# status.401

Browser compatibility

BCD tables only load in the browser

See also