Understanding HTTP Error Codes and Their Meanings

Http Error Codes

In this blog, we will explore the most common HTTP error codes and their meanings. From successful requests to client and server errors, understanding these codes is essential for troubleshooting issues in web development and ensuring smooth user experiences. Whether you're a beginner or an experienced developer, this guide will help you decode HTTP responses and handle errors effectively.

1xx: Informational

These are rarely seen by end-users and are typically used for debugging or transitional states.

  • 100 Continue: The server has received the request headers and the client should proceed to send the request body.

2xx: Success

Indicates that the request was successfully received, understood, and processed.

  • 200 OK: The request was successful, and the response contains the requested data.
  • 201 Created: The request was successful, and a new resource was created (commonly used in POST requests).

3xx: Redirection

Indicates that further action is needed to complete the request.

  • 301 Moved Permanently: The requested resource has been permanently moved to a new URL.
  • 302 Found (Temporary Redirect): The resource is temporarily located at a different URL.
  • 304 Not Modified: The resource has not been modified since the last request; the client can use its cached version.

4xx: Client Errors

Indicates issues with the client’s request.

  • 400 Bad Request: The server cannot understand the request due to invalid syntax.
  • 401 Unauthorized: Authentication is required and has either failed or not been provided.
  • 403 Forbidden: The client is authenticated but does not have permission to access the requested resource.
  • 404 Not Found: The server cannot find the requested resource (common when a page doesn’t exist).
  • 405 Method Not Allowed: The HTTP method used is not allowed for the requested resource.
  • 408 Request Timeout: The server timed out waiting for the client's request.

5xx: Server Errors

Indicates issues with the server itself.

  • 500 Internal Server Error: A generic error message indicating something went wrong on the server.
  • 501 Not Implemented: The server does not support the requested functionality.
  • 502 Bad Gateway: The server received an invalid response from an upstream server.
  • 503 Service Unavailable: The server is currently unable to handle the request (e.g., due to maintenance or overload).
  • 504 Gateway Timeout: The server did not receive a timely response from an upstream server.

How to Handle These Errors

  • 4xx Errors: Typically resolved by the client, such as fixing incorrect URLs, sending valid data, or authenticating properly.
  • 5xx Errors: Need attention from the server-side developer or admin to fix bugs, increase capacity, or troubleshoot upstream services.

Thank You!