One of the most often overlooked elements of SEO (though I don’t really know why, given how much coverage it gets) is the alt attribute. You will notice that I am saying alt attribute rather than alt tag, because that is what it is. ‘Alt tag’ is used so often incorrectly, for there is no <alt ></alt> in html markup, therefor it cannot be a tag, there is however, an alt attribute that is attached to other tags, for example <img src”" alt”" /> where <img /> is the tag, and src=”" and alt=”" are the attributes.

The alt attribute’s use, as many will already know; is to describe the image, because search engines and screen readers cannot see what the image is of. Leaving out alt attributes from your image tags, or leaving them empty, means that search engines are missing some of your content.

For example on the product page you may have the title of the product in the Meta title, and the H1 of the page, but not in the page copy, because the page copy may be talking about the product without actually referring to it by its specific model name. If you have an image in the page copy with another instance of the product name located in the alt attribute, this can provide some further reenforcement to search engines as to the relevance of your page.

When I first learned to build websites, I would create my site layout in photoshop, then slice the layout up and present it in a table. I would then overlay my actual textual content with an absolutely positioned div (some of my old sites are still using this layout!). The benefit of this method was of course the very small amount of coding time, and the reasonable result. The downside however, was the need for image maps for links, javasccript for rollovers, and absolutely positioned divs, which aren’t the most flexible of creatures.

How does this relate to alt attributes? Well when I used this type of layout, i would have between 9 and 18 images that were simply the background of the site – there was no real appropriate alt attribute because they would have just had to have been ‘background image1, 2, 3′ etc. The option some people take of course is to use this to their advantage and put a different key phrase in every image’s markup, but if you think that search engines don’t know that trick, then you’re stuck in the 90’s.

That said, you don’t want your alt attributes to be too bare either, ‘my product, from my company name and my services’ will always be more effective than ‘my product’, if you catch my drift. There’s a fine balance, and unlike Meta content, there is no set limit as to how many characters search engines will accept. There are however, general guidelines that you can follow; if you have trouble reading it, you’ve tried too hard. If you feel like you’re reading an advertisement, you’ve tried too hard, and finally, if you find yourself reading a list of words rather than a very short sentence, you’ve tried too hard.

I’ll be honest, I don’t like alt attributes. As a FireFox user I rarely ever see them, and I like it that way. Thought I will admit that they are useful for SEO purposes, and definitely should not be overlooked.

This entry was posted on Saturday, February 16th, 2008 at 1:43pm and is filed under Search Engine Optimisation. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.