About Me 0115: Alt Attribute & SEO Optimization

SEO Optimization images is becoming more and more essential in SEO (Search Engine Optimization) for websites. The ALT attribute is really a critical step that is often overlooked. This is often a lost chance of better rankings.

In Google's webmaster guidelines, they advise using alternative text for that images in your web site:

Images:. Make use of the alt attribute to supply descriptive text. In addition, we recommend using a human-readable caption and descriptive text round the image.

Why would they ask us to do that? The answer is easy, really; search engines have a similar problem as blind users. They cannot see the images.

Many webmasters and inexperienced or unethical SEOs abuse the use of this attribute, trying to stuff it with keywords, looking to achieve a certain keyword density, which isn't as relevant for rankings now as it once was.

On the other hand, high keyword density can, on some search engines like google, trigger spam filters, which might result in a penalty for your site's ranking. Even without this type of penalty, your site's rankings won't take advantage of this plan.
This method also puts persons who use screen readers at a greater disadvantage. Screen readers are software-based tools that actually read aloud the contents of what's displayed on the screen. In browsing the net, the alt features of images are read aloud as well.

Imagine listening to a paragraph of text which is then repetitions of many keywords. The page would be not even close to accessible, and, to put it mildly, will be found quite annoying.
What exactly is an Alt attribute?

An ALT attribute shouldn't be used like a description or perhaps a label for an image, though lots of people utilize it in that fashion. Though it might seem natural to assume that alternate text is really a label or a description, it is not!

The words used within an image's alt attribute ought to be its text equivalent and convey exactly the same information or serve the same purpose that the image would.

The thing is to supply the same functional information that the visual user would see. The alt attribute text should function as a "stand in" when the look itself is not available. Think about this: If you were to replace the look with the text, would most users get the same basic information, and wouldn't it generate the same response?
A few examples:

Some SEO Optimization Tips

If your search button is really a magnifying glass or binoculars its alt text ought to be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

If the image is supposed to convey the literal contents of the look, then a description is suitable.

If it is designed to convey data, then that data is what is appropriate.

If it's meant to convey the use of a function, then the function is what should be used.

Some Alt Attribute Guidelines:

Always add alt attributes to images. Alt is mandatory for accessibility and for valid XHTML.

For images that play only a decorative role in the page, use an empty alt (i.e. alt="") or a CSS background image so that reading browsers do not bother users by uttering such things as "spacer image".

Keep in mind that it is the function from the image we're attempting to convey. For example; any button images should not range from the word "button" in the alt text. They ought to emphasize the action performed through the button.

Alt text ought to be determined by context. The same image inside a different context may need drastically different alt text.

Attempt to flow alt text with the rest of the text because that is how it is going to be read with adaptive technologies like screen readers. Someone listening to your page should hardly remember that a graphic image is there.
Please keep in mind that using an alt attribute for each image is needed to meet the minimum WAI requirements, that are used since the benchmark for accessibility laws in UK and also the rest of Europe. Also, they are required to meet "Section 508" accessibility requirements in america.

It is important to categorize non-text content into three levels:

Eye-Candy
Mood-Setting
Content and Function

I. Eye-Candy

Eye-Candy are things that serve no purpose other than to create a site visually appealing/attractive and (oftentimes) satisfy the marketing departments. There isn't any content value (though there may be value to a sighted user).

Never alt-ify eye-candy unless there is something there that will enhance the usability of the site for someone utilizing a non-visual user agent. Use a null alt attribute or background images in CSS for eye-candy.

II. Mood-Setting

This is the middle layer of graphics which may serve to set the atmosphere or set happens as it were. These graphics are not direct content and may not be considered essential, but they are important in that they help frame what's going on.

Attempt to alt-ify the second group as makes sense and it is relevant. There might be instances when doing so may be annoying or detrimental with other users. Then try to avoid it.

For instance; Alt text that's just like adjacent text is unnecessary, and an irritant to screen reader users. I recommend alt="" or background CSS images in such cases. But sometimes, it's important to get this content inside for all users.

Usually it depends on context. The same image inside a different context may require drastically different alt text. Obviously, content should always be fully available. The way you go in this case is a judgment call.

III. Content and Function

This is when the image may be the actual content. Always alt-ify content and functional images. Title and long description attributes may also be in order.
The main reason many authors can't figure out why their alt text isn't working is they don't know why the images exist. You have to determined exactly what function an image serves. Consider what it's about the image that's important to the page's intended audience.

Every graphic includes a reason for being on that page: since it either enhances the theme/ mood/ atmosphere or it is critical to what are the page is trying to explain. Understanding what the image is for makes alt text easier to write. And exercise writing them definitely helps.
A way to look into the usefulness of alternative text would be to imagine reading the page over the telephone to someone. What would you say when encountering a specific image to create the page understandable to the listener?

Besides the alt attribute you have a couple more tools available for images.
First, in level of descriptiveness title is within between alt and longdesc. It adds useful information and may add flavor. The title attribute is optionally rendered by the user agent. Remember they are invisible and not shown as a "tooltip" when focus is received via the keyboard. (A lot for device independence). So use the title attribute just for advisory information.
Second, the longdesc attribute points towards the Link to a complete description of an image. When the information found in an image is essential towards the meaning of the page (i.e. some important content would be lost when the image was removed), an extended description compared to "alt" attribute can reasonably display should be used. It may provide for rich, expressive documentation of a visual image.

It ought to be used when alt and title are insufficient to embody the visual qualities of the image. As Clark [1] states, "A longdesc is really a long description of an image...The goal is to use any period of description necessary to impart the facts from the graphic.

It would not be remiss to hope that the long description conjures a picture - the look - in the mind's eye, an analogy that is true even for the totally blind."

Even though alt attribute is mandatory for web accessibility and for valid (X)HTML, not every images need alternative text, long descriptions, or titles.

Oftentimes, you're better off just choosing your gut instinct -- if it's not necessary to include it, and if you don't have a strong urge to do it, don't add that longdesc.

However, if it's necessary for the entire page to operate, then you've to include the alt text (or title or longdesc).

What's necessary and what's not depends a lot about the function of your image and it is context about the page.

The same image may require alt text (or title or longdesc) in one spot, but not in another. If an image provides simply no content or functional information alt="" or background CSS images might be appropriate to use. However, if the image provides content or adds functional information an alt will be required and maybe even a long description will be so as. Oftentimes this kind of thing is a judgement call.