A HTTP status code, more commonly referred to simply as status code, is a three number code which is send from the webserver to the client (a web browser for example, or Google-Bot). It is an answer code from the webserver, send in response to a HTTP-request by the client. The HTTP-request itself happens when a client asks the webserver for a URL.
By transmitting the HTTP status code, the webserver is able to inform the client whether the HTTP-request has been processed successfully, or whether an error has occurred during the request for a URL.
Different HTTP status codes and their meaning
HTTP status codes are divided into five categories and each have different meanings:
- 1xx Informational
- 2xx Success (operation successful)
- 3xx Redirection
- 4xx Client Error
- 5xx Server Error
The first number in the HTTP Status Code represents the specific status category. Each category is then divided into additional status codes with different meanings.
The best known HTTP status codes
The probably best known HTTP status codes are:
- 200 – OK
Meaning: The requested resource (URL) has been found on the server and can be transmitted to the client.
- 301 – Moved Permanently
Meaning: The URL requested by the client has changed. The webserver automatically redirects the client to the new URL.
- 404 – Not Found
Meaning: The resource (URL) requested by the client could not be found on the webserver.
- 503 – Service Unavailable
Meaning: The webserver is temporarily not available. This could be due to maintenance or overload, for example.
What influence do HTTP status codes have on search engine optimisation?
You should always evaluate the HTTP status codes during the course of a website’s OnPage optimisation and improve or repair them, if necessary. Through the evaluation of HTTP status codes you will be able to shed some light on whether the webserver works well and if all available content can be accessed by clients without a hitch.
Seeing how Google-Bot will periodically crawl a website, you should make sure that all linked content and URLs are accessible. Otherwise it might happen that non-accessible content gets removed from the Google index, and will therefore be unable to show up in the search results anymore.
Detailed OnPage analysis and HTTP status code check
The SISTRIX Optimizer offers an automatic OnPage analysis of your websites and shows you all SEO relevant mistakes. Incorrect HTTP status codes, or those not beneficial for search engine optimization, will be displayed for every URL. Each type of error comes complete with its own explanation and concrete guidelines for improvements, which helps to introduce you to the Onpage-Optimisation for your website.