401 status code: The

The "401 Unauthorized Error" is a standard HTTP response status code that indicates that a request sent to a server cannot be completed because it lacks valid authentication credentials. This article lists standard and notable non-standard HTTP status codes. Standardized codes are defined by IETF as documented in Request for Comments (RFC) publications and maintained by the IANA. [1] Other, non-standard values are used by various servers. The descriptive text after the numeric code – the reason phrase – is shown here with typical value, but in practice, can be different or omitted. Learn about HTTP 401 status code meaning, causes, and solutions in this comprehensive guide. How to handle 401 unauthorized errors effectively HTTP 400 status codes are encountered when there is a problem making a request. A 401 error, in particular, happens when your browser denies you access to the page you’re trying to visit.