11 January 2010

Google Guideline - How spiders view your site

In its "Guidelines for Webmasters" document Google notes that "search engine spiders see your site much as Lynx would".

A web spider is a program that searches through the internet for content (see here for more definitions.)

Lynx is a web browser that was used in the good old days of internet before we had fancy things like mouses, graphics, or sliced bread. Put very simply Lynx is a bareboned web browser that supports a minimal set of features. You can download a free copy from this website. There are other uses for Lynx other than SEO (such as pinging a webpage in a crontab), but for SEO it is mainly used for usability and visibility testing.

If you don't feel like installing new software there are a number of online spider emulators that will try to show you how a spider views your website. One that I found is available here.

Now that we have the means to see how Google spiders view our website we can have a look at what implications the guideline has for our site.

Firstly we need to realize that search spiders "crawl" through your site by following links. Obviously if a spider is unable to read a link then it won't find the page the link points to.

Certain technologies like can make links invisible to spiders. Google can now index text from Flash files and supports common Javascript methods. They don't currently support Microsoft Silverlight so you should avoid using it (it's probably a good idea to steer away from Microsoft proprietory formats anyway no matter how much crazy monkey man screams "developers!" and sweats in his blue shirt).

Google maintains an easy-to-read list of technologies that it supports. You can find it online here.

View your site in a spider emulator or Lynx and make sure that you can navigate through the links. If you can't then there is a good chance that Google can't either.

One way to nudge spiders along is to provide a sitemap. This also helps your human readers. Remember that Google does not like you to have more than 100 links on a page so if you have a large site try to identify key pages rather than providing an exhaustive list.

Some people argue that if you need a sitemap then your navigation system is flawed. Think about it - if your user can't get to content quickly through your navigation system then how good is your site at providing meaningful content? Personally I like to balance this out and provide sitemaps as an additional "bonus" while still ensuring that all my content is within 2 clicks of the landing page.
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