About Me 0073: Alt Attribute & SEO Optimization

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

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

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

Why would they ask us to achieve that? The answer is simple, really; search engines like google 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, attempting to stuff it with keywords, looking to achieve a certain keyword density, which is not as relevant for rankings now as it once was.

On the contrary, high keyword density can, on some search engines like google, trigger spam filters, which might create a penalty for your site's ranking. Even without such a penalty, your site's rankings will not benefit from this tactic.
This method also puts persons who use screen readers at 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 features of images are read aloud too.

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

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

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

The thing is to supply the same functional information that the visual user would see. The alt attribute text should be the "stand in" in the event that the look itself is unavailable. Think about this question: If you were to replace the look using the text, would most users get the same basic information, and wouldn't it generate the same response?
Some examples:

Some SEO Optimization Tips

If a search button is 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, a description is suitable.

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

If it's designed to convey using a function, then the function 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 in the page, use an empty alt (i.e. alt="") or a CSS background image to ensure that reading browsers don't bother users by uttering things like "spacer image".

Remember that it is the function from the image we're trying to convey. For example; any button images should not include the word "button" in the alt text. They should emphasize the action performed through the button.

Alt text should be based on context. The same image in a different context may require drastically different alt text.

Attempt to flow alt text with the remainder 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 needed to satisfy the minimum WAI requirements, that are used as the benchmark for accessibility laws in UK and the rest of Europe. Also, they are 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 (in many cases) fulfill the marketing departments. There is no content value (though there might be value to some sighted user).

Never alt-ify eye-candy unless there is something there which will boost the usability of the site for somebody using 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 actually the middle layer of graphics which may actually set the mood or set the stage as it were. These graphics are not direct content and may 't be considered essential, but they are essential in that they help frame what is going on.

Attempt to alt-ify the 2nd group as makes sense and is relevant. There might be times when doing so may 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 vital that you understand this content in there for those users.

Most times it depends on context. Exactly the same image in a different context may require drastically different alt text. Obviously, content ought to always be fully available. How you use this case is a judgment call.

III. Content and Function

This is when the look is the actual content. Always alt-ify content and functional images. Title and long description attributes can also be so as.
The main reason many authors can't understand why their alt text isn't working is they don't know why the pictures exist. You need to determined exactly what function a picture serves. Think about what it's about the image that's important to the page's intended audience.

Every graphic has a reason for being on that page: because it either enhances the theme/ mood/ atmosphere or it is critical to what are the page is trying to describe. Understanding what the image is perfect for makes alt text simpler 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. 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 at your disposal for images.
First, in degree of descriptiveness title is within 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 like 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 towards the Link to a full description of the image. When the information found in an image is important to the meaning of the page (i.e. some important content would be lost if the image was removed), a longer description than the "alt" attribute can reasonably display ought to be used. It may provide for 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 really a long description of the image...The aim is by using any length of description necessary to impart the details of the graphic.

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

Although the 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 going with your gut instinct -- if it's not necessary to incorporate it, and when you don't have a strong urge to get it done, don't include that longdesc.

However, if it's necessary for the entire page to work, 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 on the page.

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