HTTP Error & Status Code Explainer
Instantly look up HTTP response status codes, understand underlying causes, and find actionable troubleshooting steps for web development and API debugging.
200 OK
201 Created
301 Moved
400 Bad Req
401 Unauthorized
403 Forbidden
404 Not Found
408 Timeout
429 Rate Limit
500 Server Err
502 Bad Gateway
503 Unavailable
Understanding HTTP Status Classes
1xx: Informational
The request was received and the process is continuing.
2xx: Successful
The action was successfully received, understood, and accepted.
3xx: Redirection
Further action needs to be taken in order to complete the request.
4xx / 5xx: Errors
Client-side or server-side failure occurred while processing the request.
Frequently Asked Questions (FAQ)
401 Unauthorized means the request lacks valid authentication credentials (you need to log in first). 403 Forbidden means the server understands who you are, but you do not have the required permissions to access that specific resource.
Use 500 Internal Server Error for unexpected unhandled application crashes or exceptions. Use 503 Service Unavailable when the server is temporarily overloaded or down for scheduled maintenance.