When you’re working with an API, you’ll often see a response code and wonder what it means. Understanding HTTP status codes is essential for all web developers, as they are essential for understanding the flow of data between the client and the server. To help you, here is an answer to that most essential question: what are HTTP status codes?
1xx: Informational
Informational status codes are used to indicate that the request has been received and is being processed, but has not yet been fully completed. In other words, these codes are used to indicate that the server is still processing the request. This type of code is useful in that it allows the server to communicate its progress to the client without having to send a full response. This helps to reduce the load on the server, since it does not need to respond with a full response until the request is complete.
The most common type of informational codes are the 1xx series, including the 100 Continue status code, the 101 Switching Protocols status code, the 102 Processing status code, and the 103 Early Hints status code.
2xx: Success
HTTP success status codes can range from 200 (OK) to 206 (Partial Content). Each code is designed to provide information about the request, such as whether it was successful or not. The codes can also provide more detailed information, such as the number of bytes sent in a response, the type of content returned, the language settings used, the cache settings, and much more.
The most common codes in the 2xx series include the 200 OK code, the 201 Created code, the 202 Accepted code, the 203 Non-Authoritative Information code, the 204 No Content Code, the 205 Reset Content code, and the 206 Partial Content code.
3xx: Redirection
HTTP redirection status codes are an important part of the HTTP protocol and are an integral part of web development. Redirection codes are used to indicate that the browser should be redirected to another web page. These codes are often used to implement SEO (Search Engine Optimization) strategies in order to make sure that the most relevant content is available to the user.
Some of the most commonly used HTTP redirection status codes are 301, 302, 303, 307, and 308 codes, each showing that the requested resource should be found in a new location.
4xx: Client Error
HTTP client error status codes indicate that a client-side error has occurred due to an invalid request or incorrect syntax. These status codes are identified with the 4xx range of status codes, and they’re used to indicate a client-side error. They’re often referred to as 4xx status codes.
Examples of some of the most common 4xx status codes include the 400 Bad Request code, the 401 Unauthorized code, the 403 Forbidden code, the 404 Not Found code, and the 408 Request Timeout code.
5xx: Server Error
When making web requests, the browser and server must communicate with each other to ensure that the requested information is sent, received, and properly processed. When something goes wrong, the browser or server can send an HTTP status code to indicate the issue. This is especially important for web developers, who use these codes to diagnose and troubleshoot problems with their websites.
The most common 500-level codes are the 500 Internal Server Error, the 501 Not Implemented Error, the 502 Bad Gateway Error, the 503 Server Unavailable error, and the 504 Gateway Timeout Error.
Understanding the different HTTP status codes is an important part of developing web applications. Knowing which code to use for a particular response can help you improve the user experience, as well as your own debugging and troubleshooting processes.
