About Me 0081: Alt Attribute & SEO Optimization

SEO Optimization images is becoming increasingly more important in SEO (Seo optimization) for websites. The ALT attribute is really a critical step that is often overlooked. This can be a lost chance of better rankings.

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

Images:. Use the alt attribute to provide descriptive text. In addition, we recommend using a human-readable caption and descriptive text around the image.

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

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

On the other hand, high keyword density can, on some search engines, trigger spam filters, which may result in a penalty for your site's ranking. Even without such a penalty, your site's rankings will not 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 really read aloud the items in what's shown on the screen. In browsing the web, the alt features of images are read aloud as well.

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

An ALT attribute shouldn't be used as a description or perhaps a label to have an image, though many people use it for the reason that fashion. Although it might seem natural to assume that alternate text is really a label or perhaps a description, it is not!

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

The goal is to provide the same functional information that a visual user would see. The alt attribute text should function as a "stand in" in the event that the image is not available. Ask yourself this question: Should you replace the image with the text, would most users receive the same basic information, and wouldn't it create the same response?
A few examples:

Some SEO Optimization Tips

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

If an image is meant to convey the literal items in the image, then a description is suitable.

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

If it is designed to convey using 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 as well as for valid XHTML.

For images that play merely a decorative role in the page, make use of an empty alt (i.e. alt="") or perhaps a CSS background image to ensure that reading browsers don't bother users by uttering such things as "spacer image".

Remember that it's the function of the image we're attempting to convey. For example; any button images shouldn't range from the word "button" within the alt text. They ought to emphasize the action performed by the button.

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

Attempt to flow alt text with the rest from the text because that's how it will be read with adaptive technologies like screen readers. Someone hearing your page should hardly remember that a graphic image is there.
Please keep in mind that using an alt attribute for every image is required to meet the minimum WAI requirements, which are used as the benchmark for accessibility laws in UK and the remainder of Europe. They are also required to meet "Section 508" accessibility requirements in the US.

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

Eye-Candy
Mood-Setting
Content and Function

I. Eye-Candy

Eye-Candy are stuff that serve no purpose other than to create a site visually appealing/attractive and (in many cases) fulfill the marketing departments. There is no content value (though there may be value to some sighted user).

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

II. Mood-Setting

This is actually the middle layer of graphics which may actually set the mood or set happens so to speak. These graphics are not direct content and could 't be considered essential, but they are essential in that they help frame what is going on.

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

For example; 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 vital that you get this content inside for those users.

Most times this will depend on context. The same image inside a different context may need drastically different alt text. Obviously, content ought to always be fully available. How you go in this case is really a judgment call.

III. Content and Function

This is where the look may be the actual content. Always alt-ify content and functional images. Title and long description attributes can also be in order.
The main reason many authors can't figure out why their alt text isn't working is that they don't know why the images are there. You need to figured out precisely what function an image serves. Consider what it's concerning the image that's vital that you the page's intended audience.

Every graphic has a reason for standing on that page: because it either improves the theme/ mood/ atmosphere or it is advisable to what the page is attempting to explain. Knowing what the look is perfect 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 particular image to make the page understandable to the listener?

Besides the alt attribute you've got a couple more tools at your disposal for images.
First, in level of descriptiveness title is in 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 never 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 full description of the image. When the information found in an image is important to the concept of the page (i.e. some important content would be lost when the image was removed), a longer description than the "alt" attribute can reasonably display should be used. It may offer 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 a long description of an image...The goal is by using any period of description essential to impart the details from the graphic.

It wouldn't be remiss to hope that the long description conjures an image - the look - in the mind's eye, an analogy that holds true even for that 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 are better off just going with your gut instinct -- if it's not necessary to include it, and when you don't possess a strong urge to get it done, don't add that longdesc.

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

What's necessary and what's not depends a great deal on the function of the image and it is context about the page.

Exactly the same image may need alt text (or title or longdesc) in a single spot, although not in another. If an image provides absolutely no content or functional information alt="" or background CSS images might be appropriate to make use of. However, if the image provides content or adds functional information an alt will be required and maybe even a long description will be in order. In many cases this kind of thing is a judgement call.