For the websites those have plenty of pages, writing or updating a hard coded page every time by hand is a monolithic task. So they use dynamic scripts like PHP or JavaScript to insert content into pages, such websites are called as dynamic websites where content is stored in a database and the site serves as a template for the content. Furthermore the page address that results from the search of such database-driven websites is called as dynamic URL.
Example of a dynamic URL:
http://www.yourdomainname.com/profile.php?mode=view&u=7
Dynamic URLs are generated from specific queries to a site’s database resulting in the different URLs for the same content unlike to static URLs in which URL or the file name of a webpage remains same until the webmaster makes any change in its HTML code.
Problems caused by dynamic URLs
Users may find different dynamic URLs having the same content moreover they are not likely to understand what the page is all about by its dynamic URL and will not click on it as it is not making sense to them causing the obvious decrease in click through rate. On the other hand Static URL looks more trustworthy with keywords bolded in the SERP snippets causing higher click through rates (even in emails, forums & blogs) and also serves as a valuable backlink because of having key-phrase in itself.
It is also observed that, Static URLs are ranked well than dynamic URLs in major search engines because it’s a known SEO fact that if you have your targeted keywords in the domain name or the page URL then you will surely rank high. (A few years ago when Amazon.com changed to static URLs, there page rankings increased suddenly)
The different dynamic URLs for the same content create the issue of indexing same page for more than 1 URL and in turn Pagepank dilution. Google indexes all the copies of same content at varying URLs moreover it tends to return one version of these URLs with some queries and other versions with other queries.
Besides all this, Some search engines in the past used to truncate dynamic URLs with multiple parameters after a specific number of variable strings (e.g. &, ?, =), which created an issue of two actually different URLs having their content indexed under the same truncated URL.
Let’s look at this example:
http://www.somedomainname.com/forums/thread.php?threadid=78632&sort=date
http://www.somedomainname.com/forums/thread.php?threadid=12345&sort=date
Both the URLs above, point to 2 different pages but cutting off the part after (?), made them look same for Google. Now, even if you had unique pages, they would have been ignored because of their same URL.
Available solutions and beliefs
However google claims to solve above mentioned issues with dynamic URL crawling…to get rid of all this, rewriting the dynamic URL to a static is handy but for that you should be savvy enough to implement the Mod Rewrite/ISAPI Rewrite. In that way, you can have 301 redirects from the unfriendly URL to an SEO friendly URL, without making the users or a search engine aware of it. Apache’s Mod Rewrite Rule handles the conversion for you, it then rewrites the SEO friendly URL back to the dynamic URL. This makes it so that while still keeping the dynamic URL, not only your content gets indexed under SEO friendly URLs but the users on your site also see only the SEO friendly URLs.
You may take a look at this model, http://httpd.apache.org/docs/1.3/mod/mod_rewrite.html
But problem with URL rewriting is, it’s quite hard to correctly create and maintain the rewrites…as in the process, some parameters which offer the Googlebot valuable information may be kept hidden and some irrelevant parameters may be embedded in to static form that will make the combining of duplicate URLs of a same page even more difficult for Google. So Google recommends avoiding the reformation of a dynamic URL to make it look static if you are not able to figure out which parameters to remove and which to keep. For more information take a look at Google declaration,
Some people are looking this recommendation by Google in a competitive industry standpoint (as getting webmasters to stop rewriting URL’s means a great loss of indexed content by Google’s competition that might have not yet progressed in the dynamic URL field), but almost all are agreed that the best practice for SEO is still in rewriting the dynamic URLS for on-page optimization and click through purpose; while keeping it limited to hide only superfluous parameters and stop exacerbating Google’s efforts.
If you are not conveniently technical, you would not like to puzzle out the composite Mod Rewrite code and issues related to it moreover you will simply not have the time to hunt for such a new learning treasure. Fortunately, You can now implement keyword rich URLs for almost any dynamic site correctly as most content management systems (CMS) support SEO friendly static URLs without requiring any additional installations, plug-ins or expansion packs.
P.S: No information in the world is valid forever. Make sure that you check recent posts regarding the topic:)
