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HTTP Status Codes

HTTP 401 Unauthorized

401 Unauthorized

The request lacks valid authentication credentials for the target resource, so the server refused to authorize access.

401 Unauthorizedauthentication

Observed message

401 Unauthorized

Why it happens

  • The request is missing required authentication credentials.
  • The token, session, or credential provided is invalid or expired.
  • The client is using the wrong authentication method for the endpoint.

How to fix it

  1. Send valid authentication credentials for the target resource.
  2. Refresh expired tokens or sessions before retrying.
  3. Check which authentication scheme the server expects and format the request accordingly.

Official reference

MDN: 401 Unauthorized

Related errors

403 ForbiddenHTTP 403 Forbidden400 Bad RequestHTTP 400 Bad Request404 Not FoundHTTP 404 Not Found405 Method Not AllowedHTTP 405 Method Not Allowed

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401 Unauthorized: what it means and how to fix it | Error Atlas