2009 November, 30th

Mihaela Lica

Optimizing images for search engines brings obvious benefits: more traffic to a site, creating content harmony, keeping the visitors interested and converting a casual passer-by into a visitor who spends time on site. The “cool” factor of a good image has an important psychological impact on the reader: images make the visitor stay and remember the page via associations. As far as social media goes, good images give visitors a reason to “share.” There are enough examples of content gone viral because it had an impactful image.

The search engines take into consideration the entire content of a Web page. That’s why the image and sound files you display on a Web page should be related with its topic.

The best way to define this is “harmony.” The search engines want you to create harmonious content and not a soup of mismatches. Just like algebra where you group like objects together, on a web page you don’t mix the apples with the pantyhose.

“But, hey there, wait a minute,” you say. “How can the search engines judge what I display on my pages since we all know that they only read text?”

In fact, they need your help to understand images and other collateral files and that’s the advantage you have over the bots.

You have to apply the most basic SEO principles to help the bots understand the content of the image and sound files. You need to target keywords and write, yep, you guessed it, text.

Use keywords to name the image files. This works pretty much the same as naming HTML files (this topic will be analyzed in a following article).

For example an image file called cloudy-sky.jpg will usually rank higher than cloudysky.jpg or cloudy_sky.jpg. That’s because cloudy-sky has a more logical spelling (for both the search bots and the people) than cloudysky or cloudy_sky. There are SEO voices that say that Google doesn’t parse keywords in URLs when they are run together, but I wouldn’t count on this as a general rule. There are enough exceptions.

The image file name is not the only factor to making images rank.

The search engines look at the content around the images (and video and sound files) to judge their content. They take most of the information they need from that text. So it is important to have the content and the images interrelated.

A properly optimized image code will have an alternative text (“alt”) attribute, and a title tag. The ALT attribute describes your image to the search engine, and when a user searches for a certain image this is a key determining factor for a match.

The TITLE tag plays a lesser role but is important for visitors, as this text will automatically appear in the tooltip when the mouse is over the image. When the image links to a web page, the title tag acts as microcontent, describing the link to the search engine. Ideally, the alt attribute and the title tag should have different content.

But the search engines, although they do take those elements into consideration, place more weight on the text content around the image than the text placed on the image itself. So although they don’t ignore your HTML image optimization work, the search engines place more weight on the content around the images than the content on the images themselves.

This is the reason why you should write a snippet that summarizes the content of the image, in the immediate vicinity of the image. This is also why you shouldn’t stuff your ALT and title attributes with keywords.

Google uses other algorithms to rank images.

The primary purpose of inserting ALT and title attributes for images is to explain the content to the users, not to the search engines.

If the search engines don’t place so much weight on ALT attributes and image titles why should you include them? First for accessibility reasons. People who are surfing with their images turned off will still know what the image is all about. Then, if you use correct descriptions for your images, the general SEO scores for the Web page as a whole will be higher. That’s because you will have created that harmony between text, images and site that the search engines are looking for in order to rank your website.

A correctly optimized image from an HTML point of view would be:

<img src=”http://www.yourwebsite.com/img/image.jpg” alt=”Your keyword focused image description.” title=”Your keyword focused image title” width=”100” height=”100”/>

where you replace width and height with the actual sizes of the picture you want to display on your website.

Also, “keyword focused” doesn’t mean that if you have a picture of a strawberry you write “SEO chart.” Describe the picture. Write “fresh strawberry” or, if you insist on including “SEO”, find a way out like: “fresh strawberry adds beauty to SEO content.”

Remember:

• use keywords in the image file names
• do not unite the keywords but separate them with dashes, not underscores
• include keywords in the image ALT attributes
• include keywords in the image title tag
• place the image in the immediate vicinity of keyword-related content
• keep the number of unnecessary images per page as low as possible (unless you are displaying a photo gallery or product search results)

Publishers who use WordPress and don’t want to do the manual work (although it is recommended to take the extra time to achieve the best results) could also download SEO Friendly Images, a plugin which automatically updates all images with proper ALT and TITLE attributes.

Image credit: feature image courtesy Web and Rank.

• 2009/12/08 -- Search Engine Optimization Tips: Writing SEO Content
• 2010/01/13 -- WordStream Offers Free Webinar for Search Marketing Resolutions
• 2010/01/13 -- Covario Acquisition Emphasizes the Power of SEM
• 2009/11/15 -- What Is SEO and Why Is It Important
• 2009/10/01 -- PR Tips: The SEO Value of a Press Release
• 2009/02/16 -- Binary Stars: Google and the Social Media

About the Author

Mihaela Lica is senior partner at Pamil Visions PR and editor at Everything PR. She is a widely cited authority on search engine optimization and public relations issues (BBC News, Force for Good, Reuters and others), with an experience of over 7 years in online PR and SEO. Mihaela writes for SitePoint, Search Engine Journal, and other online publications. She also maintains a personal blog called eWritings. Follow Mig on Twitter or send her an email at mig [at] pamil-visions [dot] com.

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