Images are a vital component of a website. Used well they are worth the thousand words as the popular phrase goes. Used incorrectly they can confuse a thousand times too.
There is another downside of using images in the right context but in the wrong places. You end up losing SEO opportunities to optimize your site for search engines.
First and foremost, search engines cannot directly ‘read’ images. They have to rely on indirect information such as the alt tag and any text surrounding the image. So, if you are planning to let search engines know the title of your topic with an image, they can guess the general idea but not the specific phrase.
Where not to use images?
Wherever an image does not enhance meaning or explanation, it is overkill. A number of times images are used in navigation, for phone numbers, addresses and various elements which can be easily represented textually. Let us look at some of these.
For usability, this is not much of an issue since the user can see where they go when they click a menu item so long as the message is visible. Search engines on the other hand value links. The anchor text within links gives them context on what the link is about. This information is lost when images are used instead of text in links. The alt text does not help as it gives context for the image, not for the link. There are two ways you can solve this.
1. Replace images with text and use CSS or special scripts like Cufon.
2. Ensure there is a text version of your navigation on the page as well.
Address and Phone numbers
Using images means users have to type out your number or address and cannot copy this easily. No wonder your conversions are not what they should be. Also some unhappy visitors who went to your competitor over such a simple matter.
With the new microformats for addresses amongst others, search engines have stressed their need for textual information over images when it comes to addresses. Also many applications and devices make it easy to directly call numbers from a website e.g. Skype or any smartphone. They need textual information for this and images means you miss this opportunity.
Another notoriously common area where images replace a position which rightfully belongs to text is the header tag especially the H1. This tag is an important way to convey to the search engines what the main content of the webpage is. Using an image means a search engine has to guess instead of know. Another little negative mark added in your SEO effort!
There are many areas where a simple change from image to text helps. One example is banners. If all you have is a static banner with a message that also happens to contain your target keywords, then use text. CSS is great to combine images and text and show great banners on your website.
Another side benefit of using less images in the above parts is a reduced page size, less server requests and a quicker website. Page speed is now an SEO factor too.
This blog post is by Dharne & Company, an Irvine SEO firm offering professional SEO services to businesses across California and the United States.