One of the most overlooked aspects of Search Engine Optimization is the image. Yet is is very easy to optimize your images through the effective use of “alt tags.” An Alt Tag is actually an HTML image attribute and is short for Alternative Description Text.
What are Alt Tags and why are they important?
Alt Tags are also known as Alt Text. Both terms are widely used, and the purpose of this attribute is three-fold:
- Alt Tags allow those who use text-only browsers to read an image’s description, and therefore understand what image is displayed alongside the post’s textual content.
- Many visually impaired persons use programs that convert text to audio. If the image file is labeled “img1.jpg,” then that’s what the person will hear. A concise description will enable them to know what the image actually is about and therefore how it relates to the post.
- Search Engines only “read” text, and the Alt Img tag or text is where they look to index images.
What does an Alt Tag look like and where can I find it?
When you upload an image into a WordPress post, the default Alt Tag is blank, also known as “null.” Here’s an example of the HTML image code for the image I uploaded into this post:
<a href=”http://onbloggingwell.com/wp-content/uploads/2010/01/blank_photo.jpg”><img title=”blank_photo” src=”http://onbloggingwell.com/wp-content/uploads/2010/01/blank_photo.jpg” alt=”” width=”417″ height=”288″ /></a>
I changed the font color of the Alt Tag to red so you could easily see it. The first part of this snippet of HTML code is the anchor reference. This tells which URL the browser will take you to if you click on the image. In WordPress, the default is the address of the image’s file, which is what is displayed here. You can change this if you wish to redirect those who click on an image. For example, in the right sidebar, if you click on the image of The Blogger’s Checklist, you’ll be taken to an external link to that site. If you click on the image at the top of this post, you’ll be taken to the image itself.
The next area starts with the image title. You can change this when you upload an image into your post. Simply select and delete the text within the Title box of the image upload screen and type in the title you want. This is the text that displays when a viewer hovers the mouse over an image.
SRC is the image’s source code. It is the address of the image’s file. Then comes the ALT TAG, followed by other attributes, such as width, height, and if you wish, you can add “align” to display the image at the left, right, or center. This can also be done within the WordPress image upload screen.
How can I edit an image’s Alt Tag?
There are two ways. The first is to type in your image’s alternative description text into the proper field of WordPress’s image upload screen.
If you don’t use WordPress or have an older version without this Alt Tag field in the upload screen, you change the ALT TAG by simply to your post’s edit or new post screen in your blog’s dashboard. In the upper right area of the post content box, click on the HTML tab. This will display your posts code. Look for the image code you wish to edit, and type in the desired description for your image within the quotation marks that follow the word ALT.
I edited the ALT TAG for the image displayed at the top of this post. Here is the edited code for this image:
<a href=”http://onbloggingwell.com/wp-content/uploads/2010/01/blank_photo.jpg”><img title=”blank_photo” src=”http://onbloggingwell.com/wp-content/uploads/2010/01/blank_photo.jpg” alt=”blank photo” width=”417″ height=”288″ /></a>
Note that now instead of a null ALT TAG, the text “blank photo” has been added. Now that text will be displayed in text-only browsers and be heard by those who are visually impaired and use text-to-audio conversion programs. This ALT TAG will also be indexed by search engines and can be found using Google’s Image Search.
How to Write Effective Image ALT TAGS:
The first “rule” is to be as precise as possible but be brief. For example, if I’ve included a picture of my dog in a post, I could put any of the following ALT TAGS to describe her:
- A Dog
- A Miniature Dachshund
- My dog, “Miss I’m Too Cute and Adorable to Potty Outside.”
The second choice in the above list would be best. Although the third option is often true, it doesn’t tell my audience what exactly is being displayed. Plus it’s overdone. I can almost hear Dave screaming at Alvin to stop overdoing it (in the Chipmonk’s Christmas Song).
Using Keywords within Image ALT TAGS
If I’m writing a post about miniature dachshunds, then the example above would be a way to use a good description of the image as well as include my post’s keyword phrase. Some bloggers abuse the ALT TAG function by including a long stream of keywords that in no way describe what is being displayed in the image. Remember (and I’ve said this in many previous SEO Saturday posts), write humans and the search engines will follow. This goes for your post content as well as image ALT TAGS.
When to use a “Null” tag
If the image has no real contribution to your post, such as a divider or some decorative spacer image, it’s best to simply leave the ALT TAG with no text between the quotation marks. You’re likely not trying to get good search engine results for the word “spacer” or “divider,” and this may confuse those with text-only browsers or audio readers.
If you haven’t been using the ALT TAG in your images, you can go back through and edit them to help boost your Search Engine Results in the Google Image Search.