HTTP status codes are a way that web browsers and servers communicate. A client, usually your browser or computer, will request a web page and the server will send back an HTTP response. The response includes an HTTP status code that lets the client know the status of the web page.
There are five different types of HTTP status codes that help client and server communication:
|HTTP code range||HTTP response meaning|
|200-299||Client request successful|
|300-399||Client request redirected, further action required|
|400-499||Client request incomplete|
(Source: HTTP Pocket Reference)
There are many HTTP status codes but only a handful are important with regards to SEO. Let’s run through the status codes that you should be actively monitoring on your website.
A response code of 200 OK is what you’d expect to see when your page is working correctly and can be served to a website visitor. You want all your important pages to be returning a 200 OK.
A response code of 301 Moved Permanently is when a URL has been moved to a new URL. It’s also known as a 301 redirect in the SEO industry and they are very important when moving contents location. A 301 redirect will pass all the SEO value from one page to another.
A response code of 302 is the same as a 301, but the critical difference is that research has shown that it is not as effective in passing SEO value. That is why it is known as a temporary redirect.
The dreaded response of 404 Not Found is when a particular page or resource cannot be found on the server. Responses of 404 Not Found are perfectly normal on the web and you won’t be penalised by Google. However, too many can lead to a poor user experience and loss of SEO value on URLs. It’s best practice to 301 redirect URLs to their new location.
Rather than the page is missing or not found, a 500 is an error with your server. You don’t want to have these issues and should have a developer investigate it immediately.
You can easily monitor for status code errors in the Crawl Errors report in Google Search Console.
Keep an eye on the different types of status code errors. Remeber 4xx errors are client errors that can be fixed with a 301 redirect and 5xx errors a server errors which your developer can fix.