What does HTTP 401 mean?
Authentication is required or the supplied credentials are invalid.
Common causes and when you see it
Missing, expired or incorrect API key, token or password.
How to fix or handle it
Send valid credentials, for example an Authorization: Bearer token or X-API-Key header, and refresh expired tokens.
Test it yourself
Send a request with the online API tester, inspect the response with the HTTP header checker, or host an endpoint that returns 401 with the mock API generator to see how your app reacts.
HTTP 401 questions
Authentication is required or the supplied credentials are invalid.
Missing, expired or incorrect API key, token or password.
Send valid credentials, for example an Authorization: Bearer token or X-API-Key header, and refresh expired tokens.