About Me 0052: Alt Attribute & Seo

SEO Optimization images has become increasingly more essential in SEO (Search Engine Optimization) for websites. The ALT attribute is a critical step that is sometimes forgotten. This is often a lost opportunity for better rankings.

In Google's webmaster guidelines, they advise the use of alternative text for that images on your web site:

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

Why would they ask us to do that? The answer is simple, really; search engines like google have the same problem as blind users. They can't begin to see the images.

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

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 such a penalty, your site's rankings will not take advantage of this tactic.
This process also puts persons who use screen readers in a greater disadvantage. Screen readers are software-based tools that actually read aloud the items in what is displayed on the screen. In browsing the web, the alt attributes of images are read aloud as well.

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

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

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

The goal would be 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 unavailable. Ask yourself this question: If you were to replace the look with the text, would most users get the same basic information, and wouldn't it create the same response?
A few examples:

Some SEO Optimization Tips

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

If the image is supposed to convey the literal items in the image, then a description is appropriate.

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

If it is designed to convey using a function, then your function itself is what ought to 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 only a decorative role within the page, use an empty alt (i.e. alt="") or a CSS background image so that reading browsers don't bother users by uttering such things as "spacer image".

Remember that it is the function from the image we are attempting to convey. For instance; any button images shouldn't range from the word "button" in the alt text. They should emphasize the action performed by the button.

Alt text should be determined by context. Exactly the same image in a different context may require drastically different alt text.

Attempt to flow alt text with the remainder of the text because that is the way it is going to be read with adaptive technologies like screen readers. Someone listening to your page should hardly be aware that a graphic image is there.
Please keep in mind that utilizing an alt attribute for every image is needed to meet the minimum WAI requirements, that are used as the benchmark for accessibility laws in UK and the rest of Europe. They are also necessary 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 stuff that serve no purpose other than to make 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 which will enhance the usability of the site for somebody utilizing a non-visual user agent. Make use of a null alt attribute or background images in CSS for eye-candy.

II. Mood-Setting

This is the middle layer of graphics which may actually set the mood or set happens as it were. These graphics aren't direct content and may not be considered essential, but they're essential in they help frame what's going on.

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

For example; Alt text that's identical to adjacent text is unnecessary, and an irritant to screen reader users. I suggest 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 use this example is a judgment call.

III. Content and Function

This is when the look 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 that they don't know why the images are there. You need to determined precisely what function an image serves. Consider what it's about the image that's vital that you the page's intended audience.

Every graphic includes a reason behind being on that page: because it either enhances the theme/ mood/ atmosphere or it is critical to what the page is trying to describe. Knowing what the look is for makes alt text simpler to write. And practice writing them definitely helps.
A method to check the usefulness of alternative text is to imagine reading the page over the telephone to someone. An amount you say when encountering a particular image to make 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 in between alt and longdesc. It adds useful information and can add flavor. The title attribute is optionally rendered through the user agent. Remember they are invisible and not shown as a "tooltip" when focus is received through the keyboard. (A lot for device independence). So make use of the title attribute just for advisory information.
Second, the longdesc attribute points to the Link to a full description of an image. If the information contained in an image is important towards the meaning of the page (i.e. some important content would be lost if the image was removed), a longer description compared to "alt" attribute can reasonably display should be used. It may offer rich, expressive documentation of the visual image.

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

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

Although the alt attribute is mandatory for web accessibility as well as for valid (X)HTML, not all images need alternative text, long descriptions, or titles.

In many cases, you're best just going with your gut instinct -- if it's not necessary to incorporate it, and if you don't possess a strong urge to do it, don't include that longdesc.

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

What's necessary and what's not depends a great deal 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 absolutely 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 would be required and maybe a long description would be so as. Oftentimes this type of thing is a judgement call.