HTTP Status Codes | Website Status Codes, What are Header Status Codes

HTTP Status codes are codes returned by a server indicating the status of a requested document. Typically status codes are used by browser agents such as Mozilla, Internet Explorer etc, to identify if a page exists, if the agent has the correct permissions, if the document has moved and lots more. Search engines also use header status codes to identify the document as either Ok, Moved Temporarily, Moved Permanently, or not found.

All documents in a website should return as a HTTP 200 which signifies OK, this means that the document is present and can be requested.

HTTP 200:

Means the document can be requested and that it exists, this should be returned for all the pages within your website unless they have been redirected.

HTTP 301:

Means the document has moved permanently, in this case, the URL that was once followed will be replaced by the new location.

HTTP 302:

Means the document has moved temporarily, in this case, the old URL will remain as it will become useful when the re-direct is lifted.

HTTP 400:

Means that the document can no longer be found at the given URL, search engines will treat this as a broken link.

HTTP 404:

Means that the document can no longer be found and that no alternative document could be provided.

Of course they are only some of the many status codes that are in existence. Typically these are the most common status codes as these are present through most SEO and development projects. The first number indicates the series that the status codes belong too. Http 2xx codes are typically codes that mean the document exists, the proceeding numbers provide the actual state of the document at the time it was requested.

Frequent HTTP Status codes as per the W3 Directive:

201 Created

202 Accepted

203 Non-Authoritative Information

204 No Content

205 Reset Content

206 Partial Content

Why are Status Codes Important?

Status codes are vital to user agents and search engines because they provide clear instructions and permissions. If a document has a particular function, it will return a code to notify the user agent, for example, some documents process forms which makes a post or GET request. These documents will typically return more than one header status depending on the stage of its processing.

Other documents provide an indication to search engines for their location. If a document has moved, a status code can be assigned to the moved document to update search engines on the new location, this is a part of a 301 or 302 re-direct.

Importance of Status Codes

This is CRITICAL to search engine optimisation and website usability, if a document cannot be found, it could potentially affect the websites status whilst causing page rank to dissipate.

Common tags within SEO are 200, 301 and 302. All documents should utilise HTTP 200 to reflect that they have been found, if any of the documents move permanently they should be assigned a 301. 302 redirects should only be used temporarily, perhaps during a website migration or editing process.