HTTP/1.1 Status Codes Overview

1. Introduction

HTTP status codes are issued by a server in response to a client's request made to the server. They represent the outcome of the request and provide information about what happened during the process.

2. Status Codes

HTTP/1.1 defines a set of status codes that can be grouped into five categories. Each status code is a three-digit number, and the first digit indicates the response type.

2.1 List of Common Status Codes

200 OK: The request has succeeded.
201 Created: The request has succeeded, and a new resource has been created.
204 No Content: The server successfully processed the request, but is not returning any content.
400 Bad Request: The server could not understand the request due to invalid syntax.
401 Unauthorized: The request requires user authentication.
403 Forbidden: The server understands the request, but refuses to authorize it.
404 Not Found: The server can't find the requested resource.
500 Internal Server Error: The server encountered a situation it doesn't know how to handle.

3. Categories of Status Codes

Status codes are categorized into five classes based on the first digit of the code:

100-199: Informational responses
200-299: Successful responses
300-399: Redirection messages
400-499: Client error responses
500-599: Server error responses

4. Best Practices

Tip: Always use the most specific status code that accurately reflects the outcome of the request.

4.1 Guidelines

Use 200 OK for successful GET requests.
Use 201 Created for POST requests that create resources.
Return 204 No Content for successful requests that do not return data.
Utilize 404 Not Found for unknown endpoints.
Log unexpected status codes for debugging and monitoring.

5. FAQ

What does a 404 error mean?

A 404 error indicates that the server can't find the requested resource. It is often displayed when a user tries to access a page that doesn't exist.

How do I handle 500 errors?

500 errors are server-side errors. They can be caused by various issues, such as server misconfigurations or application errors. Ensure to log these errors for further investigation.