501
Updated: 08/02/2020 by Computer Hope
501 may refer to any of the following:
1. 501 is an HTTP (hypertext transfer protocol) status code for not implemented; generated because a server cannot fulfill a request or lacks the capability to recognize the request method.
Tip
See our HTTP definition for a listing of other error codes.
2. 501 is an area code, see our 501 area code listing for further information.