I talked with someone recently that was reading the Google blog and saw a post about URL rewriting being unnecessary. I wanted to comment here because a lot of people don’t understand the perspective Google is writing many of their ‘how to’ blog posts from. SEO testing has shown URL rewriting does work well and makes it easier for the engines to index pages. It’s also beneficial to have URLs that accurately describe the content in a good hierarchy. Logical layout comes directly from Google’s Webmaster guidelines. The problem with rewriting comes when someone does not know what they are doing and inadvertently causes serious spidering/indexing problems for the search engines.

Google’s stance is always ‘don’t make our job harder’. They have always promoted URL rewriting and apparently there are now more people messing their sites up with it than fixing things so they no longer promote it. The biggest thing to consider in Google’s comment is this:

Should I try to make my dynamic URLs look static?

Following are some key points you should keep in mind while dealing with dynamic URLs:

1. It’s quite hard to correctly create and maintain rewrites that change dynamic URLs to static-looking URLs.
2. It’s much safer to serve us the original dynamic URL and let us handle the problem of detecting and avoiding problematic parameters.
3. If you want to rewrite your URL, please remove unnecessary parameters while maintaining a dynamic-looking URL.
4. If you want to serve a static URL instead of a dynamic URL you should create a static equivalent of your content.

Their main premise here is that it is hard to rewrite URLs and it can cause more problems than it’s worth for novice Webmasters. Basically, Google doesn’t like the fact people can make dynamic content appear static via the URL. If used properly though, URL rewrites can be invaluable to a site.

For your rewrite to be effective make sure you consider the following:

1. URLs should be logical and follow a hierarchy. If your site is structured into categories and products, a good URL would look like this: http://www.yourdomain.com/category/product.html. This makes sure a URL is treated like breadcrumbs. A dynamic URL generally shows no hierarchy at all.
2.Make sure you don’t end up with duplicate content on your site.
3. Make sure the rewrite actually works properly and isn’t returning the wrong pages, 404s, etc… It’s best to use some kind of spider simulation tool and spider the site yourself.
4. The URLs should remove as many unnecessary parameters as possible. Simply converting an ugly dynamic URL to an ugly static URL doesn’t help anything. Dividing variables with / instead of & does not a good URL make.

The facts of the matter are that good, clean URLs are better for search engines and users alike. Saying dynamic URLs are better than static URLs goes against all accepted rules of usability. Just don’t break your site with a rewrite that doesn’t work correctly. You really have to be careful what you take from Google’s blog posts because they are aimed at the entire base of Webmasters and not necessarily at mid to high level programmers. This post from Google is basically throwing the baby out with the bath water.