18 Common HTTP Status Codes You Must Know

HTTP, the backbone of communication on the internet, relies on status codes to convey the outcome of a client’s request. Understanding these codes is fundamental for any web developer or enthusiast.

Let’s delve into some common HTTP status codes and decode their meanings, this generally comes with HTTP status message.

1. HTTP 200 Series

These codes signify successful requests:

  • 200 OK: The request was successful.
  • 201 Created: Indicates that the requested resource has been created.
  • 202 Accepted: The request has been accepted for processing.
  • 204 No Content: The server successfully processed the request but returns no content.

2. HTTP 300 Series

These codes indicate redirection or further action:

  • 301 Moved Permanently: The requested resource has been permanently moved to a new location.
  • 302 Found: The requested resource temporarily resides under a different URI.
  • 304 Not Modified: The client’s cached copy is still valid; no modification needed.

3. HTTP 400 Series

These codes signify client-side errors:

  • 400 Bad Request: The server cannot process the request due to malformed syntax.
  • 401 Unauthorized: Authentication is required to access the resource.
  • 403 Forbidden: The client does not have permission to access the resource.
  • 404 Not Found: The requested resource could not be found.
  • 405 Not Allowed: The method specified in the request is not allowed for the specified resource.
  • 408 Request Timeout: The server timed out waiting for the request.

4. HTTP 500 Series

These codes indicate server-side errors:

  • 500 Internal Server Error: A generic error message indicating a server-side problem.
  • 501 Not Implemented: The server does not support the functionality required to fulfill the request.
  • 502 Bad Gateway: The server, while acting as a gateway or proxy, received an invalid response from the upstream server.
  • 503 Service Unavailable: The server is currently unable to handle the request due to temporary overloading or maintenance.
  • 504 Gateway Timeout: The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server.


Understanding these HTTP status codes provides valuable insights into troubleshooting web-related issues and ensuring smooth communication between clients and servers. By mastering these codes, developers and any other tech person can effectively diagnose and resolve various web-related problems, enhancing the overall user experience.

Leave a Reply

Your email address will not be published. Required fields are marked *