SEO Problems With Site Navigation

To make it possible for the major search engines to find your site’s pages, it is important that your site has good internal navigation. If a search engine can’t get at all of your site’s pages, there’s no hope for those pages showing up in the search engine results pages. This means avoiding common designs that search engines can’t deal with, or accommodating the search engines with alternatives.

Text Links and Image Links

The best navigation scheme for search engines are text links with keyphrases in the linking text. Image links with alt text are also acceptable, although they probably have less potential in improving rankings. Alt text usually is not visible to the user, and common sense dictates that factors that are not visible to users will get less weight in the rankings since they are more susceptible to manipulation.

JavaScript and Flash

Links hidden in JavaScript or Flash are not visible to search engines. Although navigation that is in Flash looks more appealing to the user, it will not get search engines to your pages. If Flash is used for the main navigation, there should also be an alternate form of navigation, such as text links at the bottom of each page.
Similar to Flash, search engines do not execute JavaScript. JavaScript links are typically easy to identify. They usually use an event handler like “onClick” and then a short script that changes the location value of the window object. When you mouse over a link, if the display in the lower left corner of your browser says something like:
javascript:scriptedLink (‘somelink.htm’)
instead of:

http://www.domain.com/somelink.htm

then it is a link hidden in JavaScript (this is a general guide with a lot of exceptions).
There are different reasons why a designer might use JavaScript to link to a page:

• The page that’s being opened might depend on some condition which JavaScript is being used to evaluate.
• The page being opened might be getting resized by JavaScript.
• The designer might be purposely hiding the destination from search engines (to stop PageRank from getting distributed, or something along these lines).

If you want pages that are linked to with JavaScript to be visible to search engines, you have to get other non-JavaScript links to the page or you need to make use of the <noscript> tag. The HTML between a <noscript> tag is used if a client (i.e. the search engine spider) does not execute JavaScript.

Frames

A page with frames is like multiple web pages shown in one window. With frames, the same URL can have different content. This causes problems for users and search engines. If a user wants to e-mail a link to a friend so they can see framed content, their friend won’t be able to follow the link and see what they were looking at (most of the time).
Search engines don’t index framed content for a particular URL. If they could and a single URL had multiple versions, which version would they show? Using frames for navigation is a bad idea and should be avoided. There are other more appropriate ways to use frames, although designers nowadays usually avoid frames.