18 Essential HTTP Status Codes Every Web Developer Should Know

As a web developer, understanding HTTP status codes is crucial for troubleshooting and ensuring smooth client-server communication. Here’s a quick guide to the most important ones you need to keep in mind:

1. 200 OK:

This means your request was successful, and the server returned the desired response.

2. 201 Created:

A new resource has been successfully created as a result of the request.

3. 202 Accepted:

The request has been accepted for processing, but the operation is not yet completed.

4. 204 No Content:

The server successfully processed the request, but there’s no content to send back.

5. 301 Moved Permanently:

The requested resource has been permanently moved to a new URL.

6. 302 Found:

The resource is temporarily located at a different URL.

7. 304 Not Modified:

The cached version of the resource is still valid, so no new data is returned.

8. 400 Bad Request:

There’s something wrong with the request, and the server can’t process it.

9. 401 Unauthorized:

Authentication is required to access the resource.

10. 403 Forbidden:

You’re not allowed to access the requested resource, even with authentication.

11. 404 Not Found:

The server couldn’t find the requested resource.

12. 405 Method Not Allowed:

The request method is not supported for the resource.

13. 408 Request Timeout:

The server timed out waiting for the client’s request.

14. 500 Internal Server Error:

Something went wrong on the server, and it’s unable to complete the request.

15. 501 Not Implemented:

The server doesn’t support the functionality required to fulfill the request.

16. 502 Bad Gateway:

The server received an invalid response from an upstream server.

17. 503 Service Unavailable:

The server is currently unavailable, usually due to maintenance or overload.

18. 504 Gateway Timeout:

The gateway server didn’t receive a response in time from an upstream server.

Understanding these status codes helps you quickly identify issues during development, making debugging smoother and more efficient.