Todays online world is full of new dynamic websites that offer more dynamic features than ever before. Primitive websites in the mid 90's rarely had any functionality other then basic form posting and e-mail functionality.
As time has gone on, there has been evolution in web technology including PHP, ASP, ASP.NET, JS, CSS, Javascript, Flash, AJAX and many other technologies.
The key difference between technologies is the way that they process and handle information. Some technologies are better suited to websites then others.
Todays online world is full of flashy websites that let you shop, calculate, process information, perform complex operations and much more. But how does this affect SEO? If we was together all the ways that dynamic technologies have an impact on SEO then the document would be thousands of pages long, so we will cover the basics.
Dynamic websites are exactly what they say, dynamic, meaning that the page displayed can be dependent on a number of factors, anything from the users login details to the visitors geographics. These web technologies really do offer millions of dynamic features.
Search engines have frequently had to overcome hurdles with dynamic websites, such as, when the website is visited by the search engine, what data is represented and does this data differ from what the user sees?. Or, when the search engine requests the page, is any textual content available, or is it only available when a visitor performs a certain action on the page?
Think of the immense problems that these issues can cause, imagine a visitor visiting a website that is dynamically generated, when a search engine visits it, it does not behave the same way a visitor does, meaning that there is potential for lots of things to go wrong.
Thankfully, with the evolution of these technologies, developers have found multiple ways to ensure a dynamic website remains SEO friendly.
Lets look at some of the common problems presented by dynamic websites.
Content Availability:
Dynamic websites can generate pages on the fly, meaning that when a visitor visits a page, the content is displayed. Search engines may not be able to index content unless something static exists. Developers typically have pages that always generate content even when a search engine user agent requests them, meaning that search engines get to index some form of content from the page.
Websites running on .NET are the biggest culprits of content delivery issues, although most distributions of .NET websites now provide raw content on page request.
Check with your webmaster on the websites policies, and how it behaves when user agents request the pages.
Dynamic URLs:
Dynamic URL's are very common, and many still present a problem to search engines. Dynamic URL's are URL's that are generated depending on the pages given criteria. This means that the page may remain the same, yet the URL may change. Imagine the problems this could cause for search engines.
If a search engine requests a page and indexes a URL, that URL may become invalid very quickly, meaning that Google could index a whole site full of erroneous URL's.
Dynamic URL's are often very long, more than 100 characters in length, causing truncation issues in Google's index. These URL's can appear messy in search results, as well as holding variables in them that way change or become nonexistent, meaning that if a visitor clicked on the URL from the search index, they maybe presented with a broken page or a page that is not rendered correctly.
Websites that are dynamic typically utilize databases, which means that a webpage Is generated via the means of a scripting language such as PHP, Javascript or AJAX which are development technologies. Dynamic websites are a common preference as they allow for automated tasks to become a quick and easy process rather then using static pages that can take a long time to edit or update.
Dynamic URL's will present a hazard in any SEO project, you will be able to recognize a dynamic URL, it will appear in a similar format to the example below:
www.mywebsite.com/forums/post.php?id=290940_&procid=form29848&sort=values
As you can see, the URL above shows lots of characters including & = and _. This URL is classed as dynamic because it has processing requirements in the URL, such as sort=values, meaning that the page should be arranged by values.
Search engines can index these URL's but will typically truncate the URL after the first set of processing variables.
So Google may index the URL as:
www.mywebsite.com/forums/post.php
or:
www.mywebsite.com/forums/post.php?id=290940
Although this may seem intelligent for search engines, it can create massive problems because other pages using the post.php script may also have different content, if search engines trim the same URLs and ignore the variables, you will end up having the same page indexed with different content and data.
This will cause all sorts of duplication issues, and even supplemental results, meaning that the page is not relevant and is unlikely to be returned for any sort of search query.
So,
www.mywebsite.com/forums/post.php?id=290940_&procid=form29848&sort=values
www.mywebsite.com/forums/post.php?id=301983_&procid=form29848&sort=values
Above, is the same post.php page, but it will display different content because of the variables in the URL, and because these variables are ignored, the 2 pages will be indexed as a duplicate result.
So how do you overcome this?
URL rewriting is the answer.
URL rewriting is the process of converting dynamic URL's into static URL's using your web servers technology. Using URL rewriting you can automatically generate URL's that static in appearance, even if they use the same source page, i.e.
www.mywebsite.com/forums/post.php?id=290940_&procid=form29848&sort=values
could become:
www.mywebsite.com/forums/my-car-wont-start/
URL rewriting is a complex system that should be enabled by your websites administrator or by your webhost. This will be covered later on in this document on how to implement URL rewriting.
Another culprit is search applications within a website.
Millions of websites across the internet using search facilities in their website to help users find what they are looking for.
Because of this system, a lot of websites suffer the indexation problem because search engines cannot emulate user behavior, items such as filling out form fields is not possible by search engines, meaning any content hidden behind those forms cannot be reached.
For example:
If you have a skiing website and you use a search function so that visitors can find a ski holiday, if your websites pages on ski holidays are hidden behind this search form system, they will not be accessible to search engines as the diagram below demonstrates.
Many websites suffer from this issue and can suffer critical ranking problems if internal pages on the website cannot be accessed via a different method.
To avoid this issue you should always make sure you have a group of pages that interconnect directly from the homepage to ensure that the search feature is visitor based only.
Providing a sitemap alone is not good enough as this will mean pages can only be reached through this method by search engines. If they determine this to be the only way through, they may devalue the website.
See the previous section again on interlinking to help overcome this problem.
