401 Unauthorized

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

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
401	Yes	12	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes

See also

• HTTP authentication
• WWW-Authenticate
• Authorization
• Proxy-Authorization
• Proxy-Authenticate
• 403, 407