Lizards: Alt Attribute & SEO Optimization

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

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

Images:. Make use of the alt attribute to provide 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 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 is not as relevant for rankings now since it was previously.

On the other hand, high keyword density can, on some search engines like google, trigger spam filters, which might create a penalty for the site's ranking. Even without such a penalty, your site's rankings will not take advantage of this tactic.
This method 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's shown 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 numerous 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 should not 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!

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

The thing would be to supply the same functional information that a visual user would see. The alt attribute text should function as a "stand in" when the look is not available. Ask yourself this: Should you replace the image using the text, would most users receive the same basic information, and wouldn't it generate the same response?
A few examples:

Some SEO Optimization Tips

If a 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 meant to convey the literal contents of the look, then a description is appropriate.

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

If it is designed to convey using a function, then your 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 only a decorative role within the page, make use of 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 of the image we're 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. The same image in a different context may require drastically different alt text.

Attempt to flow alt text with the rest from the text because that is the way it is going to 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 since the benchmark for accessibility laws in UK and the remainder 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) satisfy the marketing departments. There isn't any content value (though there might be value to a sighted user).

Never alt-ify eye-candy unless there's something there that will boost 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 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 could 't be considered essential, but they are essential in that they help frame what's going on.

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

For example; Alt text that's identical to adjacent text is unnecessary, as well as an irritant to screen reader users. I suggest alt="" or background CSS images in such instances. But sometimes, it's vital that you get this content inside for those users.

Most times this will depend on context. Exactly the same image in a different context may need drastically different alt text. Obviously, content ought to always be fully available. How you go in this example 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 that they don't know why the pictures are there. You need to figured out exactly what function a picture serves. Think about what it is concerning the image that's vital that you the page's intended audience.

Every graphic has a reason behind standing on that page: because 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 perfect for makes alt text simpler to write. And exercise writing them definitely helps.
A method to check the usefulness of alternative text would be to imagine reading the page on the phone to someone. What would you say when encountering a particular image to make the page understandable towards the listener?

Aside from the alt attribute you've got a couple more tools available for images.
First, in degree 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 never shown as a "tooltip" when focus is received via the keyboard. (So much 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. If the information found in an image is essential to the meaning of the page (i.e. some important content would be lost if the image was removed), an extended description compared to "alt" attribute can reasonably display should be used. It may offer rich, expressive documentation of the visual image.

It ought to 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 an image...The goal is to use any period of description essential to impart the details of the graphic.

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

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

Oftentimes, you are best just choosing your gut instinct -- if it's not essential to include it, and if you don't possess a strong urge to do it, don't include that longdesc.

However, if it's essential for the whole page to operate, then you have to include the alt text (or title or longdesc).

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

The same image may require alt text (or title or longdesc) in a single spot, although not in another. If the image provides simply no content or functional information alt="" or background CSS images might be appropriate to use. But 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.