The Official Google Webmaster Central Blog has a very interesting post on “Dynamic URLs vs. static URLs” and how Google deals with them as well as demystifying some of the rumours surrounding dynamic URLs.
The article starts by explaining the basic difference between the two types of URL and goes on to explain that, yes, Google can crawl and index dynamic URLs and has been able to do for a very long time. Personally I’ve known that and observed it in practice for several years whilst performing SEO on Action Figure Supplies, a site that uses dynamic URLs and has a very large number of number 1 rankings on all the major search engines.
A few parts of the article in particular caught my eye:
“One recommendation is to avoid reformatting a dynamic URL to make it look static. It’s always advisable to use static content with static URLs as much as possible, but in cases where you decide to use dynamic content, you should give us the possibility to analyze your URL structure and not remove information by hiding parameters and making them look static.”
“Does that mean I should avoid rewriting dynamic URLs at all?
That’s our recommendation, unless your rewrites are limited to removing unnecessary parameters, or you are very diligent in removing all parameters that could cause problems. If you transform your dynamic URL to make it look static you should be aware that we might not be able to interpret the information correctly in all cases… However, if you’re using URL rewriting (rather than making a copy of the content) to produce static-looking URLs from a dynamic site, you could be doing harm rather than good.”
These recommendations certainly underline the results of a recent experiment I did with URL rewriting on a client’s site, Rainbow Signs and Safety. I installed a third-party rewriting module into the customer’s third-party shopping cart software to create “SEO friendly URLs” which I hoped would help improve the site’s rankings for it’s sub-pages and large product catalogue. Basically it took URLs such as:
and turned it into:
Useful as it’s putting the product name in the URL, which has to help rankings, right? Wrong. Apart from the numerous sitemap errors that Google Sitemaps threw up (mainly about 302 redirects) and the incorrect stats that Google Analytics reported it also adversely affected the site’s rankings. Although the effect wasn’t massive, it was noticeable and also happened on MSN and Yahoo rankings as well. So I recently turned the module off and resubmitted the un-rewritten URLs to Google, Yahoo and MSN and the rankings are returning.