Choose Text-Based Site Navigation for Better Search Engine Results
Text-based navigation is where all of the navigation info (links, information about those links, any cool little widgets you have, and so on) is listed in the text. There are a few reasons why you should rely on this when designing your page: Search engines can read the content of your text and can use the anchor text in the links to assign weight and relevance to those pages. Text is also clean, simple, and easy to use, and you don’t run the risk of users being unable to see it in their browsers because all browsers can read text.
If you’re still considering any of the other methods, read on.
Why image maps are bad for site navigation
Using an image map for your site navigation doesn't help with search engine optimization because you don't have any anchor text to take advantage of. Your anchor text is important because it tells the search engine what that page you are linking to is about. When a page is linked to the anchor text classic cars, search engines tend to think, "Hmm, this must be about classic cars." The more links you have with that anchor text pointing into that page from other pages, the more it's like a giant blinking neon sign telling the search engine that this page is about classic cars. The search engine then assigns more weight to the link and increases the perceived relevance of the linked page.
Because an image map does not contain any readable text, any text that is contained within the image is not going to be seen by a search engine spider. A spider is deaf, dumb, and blind and can only understand the code on the page, not what a human user sees. Any text within the navigation is not counted toward your overall page rank. The only text it’s going to read is the Alt attribute text. And because you have one image for the navigation, that’s only going to be one Alt attribute tag. Some designers break up a big image into several smaller images so that they can use multiple Alt attribute tags, but Alt attribute tags still do not carry as much weight as hyperlinked text, especially because it’s very easy to deceive a search engine with spam in the Alt attribute tags.
You also must consider the possibility that users do not have images turned on in their browser, usually because they’re still on a dial-up connection and they want pages to load sometime this century. (They are still out there.)
Why Flash is bad for site navigation
Another type of navigation system is Flash. There have been some advances when it comes to Flash: Newer versions of the program have made non-animated Flash file text readable by a search engine, but this is only for the latest versions, and search engines still won’t be able to read any of the links or anchor text.
Also, some search engines see Flash files as files separate from the page they’re attached to, and do not count the Flash content towards that overall Web page. Flash can also be annoying because it can break, increase load time, or start playing unwanted music or videos. Many people choose to turn Flash off on their browsers in order to avoid Flash-based advertisements, and they wind up stranded on your page if your navigation is Flash-based because they won’t even be able to see it.
Why frames are bad for site navigation
Frames have fallen by the wayside as site design has advanced in the past several years, but a few sites out there still choose to use them. Try not to be one of them. Search engines read a frame as a completely separate page, so if your navigation is in a different frame than your page content, they're being read as two separate pages. Splitting up the relationship between your content is a bad idea. Just don’t do it.