HTTP 401 Unauthorized vs 500 Internal Server Error
HTTP 401 (Unauthorized) is a 4xx Client Error response, while 500 (Internal Server Error) is a 5xx Server Error response. 401 indicates that the request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme. In contrast, 500 means that the server encountered an unexpected condition that prevented it from fulfilling the request. A generic catch-all for server-side errors.
Description
The request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme.
When You See It
When accessing a protected resource without credentials or with expired tokens.
How to Fix
Include valid authentication credentials (API key, Bearer token, Basic auth) in the Authorization header.
Description
The server encountered an unexpected condition that prevented it from fulfilling the request. A generic catch-all for server-side errors.
When You See It
When an unhandled exception occurs, a database connection fails, or server code has a bug.
How to Fix
Check server logs for the stack trace. Common causes: unhandled exceptions, database errors, misconfigurations.
Key Differences
401 is a 4xx Client Error response, while 500 is a 5xx Server Error response.
HTTP 401: The request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme.
HTTP 500: The server encountered an unexpected condition that prevented it from fulfilling the request. A generic catch-all for server-side errors.
You encounter 401 when when accessing a protected resource without credentials or with expired tokens.
You encounter 500 when when an unhandled exception occurs, a database connection fails, or server code has a bug.
When to Use Which
For 401 (Unauthorized): Include valid authentication credentials (API key, Bearer token, Basic auth) in the Authorization header. For 500 (Internal Server Error): Check server logs for the stack trace. Common causes: unhandled exceptions, database errors, misconfigurations.