Understanding Webpage Error Codes: A Guide to HTTP Status Messages
HTTP error codes are an integral part of web communication, providing feedback about the status of a request. These codes are generated by servers to inform clients, such as web browsers, about the outcome of their requests. The first digit of the code defines its category, while the remaining two digits offer specific details. Below is a breakdown of the five main categories of HTTP status codes.
1xx: Informational Responses
These codes indicate that the server has received the request and is continuing the process.
- 100 Continue : The server acknowledges the request and asks the client to proceed.
- 101 Switching Protocols : The server agrees to switch protocols as requested by the client.
2xx: Successful Responses
These codes confirm that the request was successfully received, understood, and processed. Common examples are:
- 200 OK : The request was successful, and the server returns the requested data.
- 201 Created : The request resulted in a new resource being created.
- 204 No Content : The request was successful, but no content is returned.
3xx: Redirection Messages
These codes indicate that further action is needed to complete the request, often involving redirection. Examples include:
- 301 Moved Permanently : The requested resource has been permanently moved to a new URL.
- 302 Found : The resource is temporarily available at a different URL.
- 304 Not Modified : The resource has not been modified since the last request.
4xx: Client-Side Errors
These codes signify that the client made an error, such as requesting a non-existent page. Common examples are:
- 400 Bad Request : The server cannot process the request due to client-side syntax errors.
- 401 Unauthorized : Authentication is required to access the resource.
- 403 Forbidden : The server refuses to fulfill the request, even if authenticated.
- 404 Not Found : The requested resource could not be found on the server.
5xx: Server-Side Errors
These codes indicate that the server failed to fulfill a valid request. Examples include:
- 500 Internal Server Error : A generic error message indicating server failure.
- 502 Bad Gateway : The server acting as a gateway received an invalid response.
- 503 Service Unavailable : The server is temporarily unable to handle the request.
Comparison of Common HTTP Error Codes
| Code | Description | Category |
|---|---|---|
| 200 | OK | Success |
| 301 | Moved Permanently | Redirection |
| 400 | Bad Request | Client Error |
| 404 | Not Found | Client Error |
| 500 | Internal Server Error | Server Error |
For further reading, refer to the official documentation from MDN Web Docs or the Internet Engineering Task Force (IETF) .