About Me 0093: Alt Attribute & SEO Optimization

SEO Optimization images has become increasingly more important in SEO (Seo optimization) for websites. The ALT attribute is 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:. Use the alt attribute to provide descriptive text. In addition, we recommend utilizing a human-readable caption and descriptive text around 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 can't begin to see the images.

Many webmasters and inexperienced or unethical SEOs abuse using this attribute, trying to stuff it with keywords, hoping to achieve a certain keyword density, which is not as relevant for rankings now since it once was.

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 won't 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 contents of 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 which is followed by 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 to have an image, though lots of people use it in that fashion. Though it might seem natural to assume that alternate text is really a label or perhaps a description, it's not!

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

The goal 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 image itself is not available. Think about this question: If you were to replace the look with the text, would most users get the same basic information, and would it create the same response?
Some examples:

Some SEO Optimization Tips

If your search button is really a magnifier or binoculars its alt text should 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 suitable.

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

If it is meant 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 do not bother users by uttering things like "spacer image".

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

Alt text should be based on context. Exactly the same image in a different context may need drastically different alt text.

Attempt to flow alt text with the remainder from 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 remember that a graphic image is there.
Please remember that using 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 remainder 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 apart from to create a site visually appealing/attractive and (oftentimes) satisfy 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 which will boost the usability from 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 might serve to set the atmosphere or set the stage as it were. These graphics aren't direct content and could 't be considered essential, but they're essential in that they help frame what's 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 to other users. Then avoid it.

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

Most times it depends on context. The same image inside a different context may require drastically different alt text. Obviously, content should always be fully available. How 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 that they don't know why the pictures exist. You have to determined exactly what function a picture serves. Consider what it's about the image that's vital that you the page's intended audience.

Every graphic has a reason behind being on that page: because it either improves the theme/ mood/ atmosphere or it is critical to what are the page is attempting to explain. Knowing what the image is for makes alt text easier to write. And practice writing them definitely helps.
A way to look into the usefulness of alternative text is to imagine reading the page on the phone to someone. An amount you say when encountering a specific image to create the page understandable towards the listener?

Aside from 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 may add flavor. The title attribute is optionally rendered by the user agent. Remember they're invisible and not shown like a "tooltip" when focus is received via the keyboard. (So much for device independence). So make use of the title attribute only for advisory information.
Second, the longdesc attribute points to the Link to a complete description of an image. When the information found in a picture is important to the concept of the page (i.e. some important content would be lost when the image was removed), a longer description compared to "alt" attribute can reasonably display should be used. It can 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 a long description of an image...The aim is to use any length of description essential to impart the facts of the graphic.

It wouldn't be remiss to hope that the long description conjures a picture - the image - within the mind's eye, an analogy that is true even for that 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.

In many cases, you're best just going with your gut instinct -- if it's not essential to incorporate it, and when 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'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.

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