Understanding HTTP Status Codes

This is a guest post from our friends at The Blog Frog 🙂 I hope you find it useful

The internet has exploded in recent years and is now home to nearly 2 billion websites and growing. While the process of visiting a website is incredibly simple for you, there is actually a lot more going on behind the scenes than you might think. When visiting a website, there is an interaction that takes place between your browser and the website itself. This interaction is handled through HTTP, which is the Hypertext transfer protocol. This has been the standard since 1991 and most of the traffic throughout the internet is handled by HTTP.

The HTTP protocol as a whole can also be important for SEO specialists, as it has an impact on how a search engine will index a particular web page. In order to test this and understand it, you will likely need a capable log analyzer and other tools to make sure you aren’t missing something important. This could include incidents on your webpage or within your code that could be causing optimization issues.

In order to truly understand HTTP and navigate it successfully, you need to know about HTTP status codes. These status codes are sent by a website server in response to a client request of some kind. Their purpose is to inform the end user the type of action that has been taken place and basically acknowledges the request.

Now that you know a little about what HTTP status codes and the HTTP protocol are, let’s take a look at the different types of status codes that exist. In general, there are five main categories of HTTP status codes, and the first digit of the status code defines that category of that particular status code. While we won’t look at and describe every HTTP status code, we’ll take a brief look at each of the categories now.

1XX – Informational Codes

A response of an informational codes lets users know that the request was understood and received correctly. Essentially, these codes are telling you to wait while the process is continued and completed. Some of the codes in this category are :

  • 100 Continue
  • 101 Switching Protocol
  • 102 Processing

2XX – Successful Codes

This category of status codes is all about indicating to a user that the request was not only understood and received, but that is has been accepted, too. This is the desired code as it lets you know that the request was successful and nothing more needs to take place. Examples of this class of status codes are:

  • 200 OK
  • 201 Created
  • 202 Accepted

3XX – Redirection Codes

This class of codes indicates that additional action must be taken to complete the request. In plain english, this type of classification means you could likely return at a later time until it’s fixed. Types of codes in this class include:

  • 300 Multiple Choice
  • 301 Moved Permanently
  • 304 Not Modified

4XX – Client Error Codes

This error code is used when errors have been caused by the client. As a result, you will need to rectify the issue. Examples of these codes include:

  • 400 Bad Request
  • 403 Forbidden
  • 404 Not Found

5XX – Server Error Codes

These status codes indicate that the server has failed to complete the request. The server itself will be aware that it has encountered an error. Examples of this classification of code include:

  • 500 Internal Service Error
  • 502 Bad Gateway
  • 508 Loop Detected

In conclusion, we hope that this article has helped you understand HTTP status codes more clearly and learn what they all mean if you didn’t know before. While these are incredibly useful for SEO specialists, they can also be helpful for a wide range of other users, as well.