About Me 0053: Alt Attribute & Seo

SEO Optimization images is becoming more and more important in SEO (Search Engine Optimization) for websites. The ALT attribute is really a critical step that is often overlooked. This is often a lost chance of better rankings.

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

Images:. Use 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 do that? The answer is easy, really; search engines have the same problem as blind users. They can't begin to see the images.

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

On the contrary, high keyword density can, on some search engines, trigger spam filters, which might create a penalty for your site's ranking. Even without this type of 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 really read aloud the contents of what is displayed on the screen. In browsing the web, the alt attributes of images are read aloud too.

Imagine listening to a paragraph of text that is followed by repetitions of numerous keywords. The page would be far from accessible, and, to put it mildly, will be found quite annoying.
What exactly is an Alt attribute?

An ALT attribute should not be used like a description or a label to have an image, though many people use it for the reason that fashion. Although it may appear natural to assume that alternate text is a label or a description, it's 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 that the image would.

The thing would be to supply the same functional information that a visual user would see. The alt attribute text should be the "stand in" when the image itself is not available. 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?
Some 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 an image is meant to convey the literal contents of the image, a description is suitable.

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

If it is designed to convey using a function, then your function itself is what should be used.

Some Alt Attribute Guidelines:

Always add alt attributes to images. Alt is mandatory for accessibility and for valid XHTML.

For images that play merely a decorative role within the page, use 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".

Keep in mind that it is the function of the image we are trying to convey. For example; any button images shouldn't include the word "button" in the alt text. They should emphasize the action performed by the button.

Alt text ought to be based on context. Exactly the same image in a different context may require drastically different alt text.

Try to flow alt text with the rest of the text because that is the way it will be read with adaptive technologies like screen readers. Someone listening to your page should hardly be aware that a graphic image is there.
Please remember that utilizing an alt attribute for each image is needed to meet the minimum WAI requirements, which are used since the benchmark for accessibility laws in UK and also the rest of Europe. They are also required to meet "Section 508" accessibility requirements in the US.

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

Eye-Candy
Mood-Setting
Content and Function

I. Eye-Candy

Eye-Candy are things that serve no purpose apart from 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 that will boost the usability from 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 the middle layer of graphics which might serve to set the atmosphere or set happens so to speak. These graphics aren't direct content and may 't be considered essential, but they are important in they help frame what's going on.

Try to alt-ify the 2nd group as is sensible and is relevant. There might be times when doing so might be annoying or detrimental with other users. Then try to avoid it.

For instance; 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 instances. But sometimes, it's vital that you get this content in there for all users.

Usually it depends 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 use this case 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 can also be so as.
The 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 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 for being on that page: since it either enhances the theme/ mood/ atmosphere or it is critical to what the page is attempting to explain. Understanding what the look is for makes alt text simpler to write. And practice writing them definitely helps.
A way to check 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 towards the listener?

Aside from the alt attribute you have 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're invisible and never 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 URL of a complete description of an image. When the information contained in a picture is essential 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 can 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 really a long description of the image...The aim is by using any period of description necessary to impart the facts of the graphic.

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

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

Oftentimes, you're best just choosing your gut instinct -- if it's not essential to incorporate it, and if you don't possess a strong urge to do it, don't add 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 the 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 make use of. But if the image provides content or adds functional information an alt would be required and maybe even a long description would be in order. Oftentimes this type of thing is a judgement call.