Friday, April 22, 2011

Alt Attribute & SEO Optimization

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


In Google's webmaster guidelines, they advise the use of alternative text for that images in your web 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 simple, really; search engines have a similar problem as blind users. They cannot begin to see the images.

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

On the contrary, high keyword density can, on some search engines, trigger spam filters, which may create a penalty for the site's ranking. Even without such a penalty, your site's rankings won't benefit from this tactic.
This method also puts persons who use screen readers at a greater disadvantage. Screen readers are software-based tools that really read aloud the items in what's shown on the screen. In browsing the net, the alt features of images are read aloud too.

Imagine listening to a paragraph of text which is then repetitions of many keywords. The page would be not even close to accessible, and, to put it mildly, will 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 utilize it for the reason that fashion. Although it might seem natural to assume that alternate text is really a label or a description, it's not!

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

The goal is to provide the same functional information that a visual user would see. The alt attribute text should function as a "stand in" when the image is unavailable. Think about this: If you were to replace the image 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 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, a description is suitable.

If it is designed to convey data, then that data 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 and for valid XHTML.

For images that play only a decorative role within the page, make use of an empty alt (i.e. alt="") or perhaps a CSS background image to ensure that reading browsers don't bother users by uttering things like "spacer image".

Keep in mind that it is the function from the image we're trying to convey. For example; any button images shouldn't include the word "button" within the alt text. They ought to emphasize the action performed through the button.

Alt text ought to be determined by context. Exactly the same image in a different context may need drastically different alt text.

Try to flow alt text with the remainder from the text because that's how 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 can there be.
Please remember that using an alt attribute for every image is needed to meet the minimum WAI requirements, that are used since the benchmark for accessibility laws in UK and the remainder of Europe. They are also necessary 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 (in many cases) fulfill the marketing departments. There is no content value (though there might be value to a sighted user).

Never alt-ify eye-candy unless there's something there that will enhance 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 actually the middle layer of graphics which might serve to set the atmosphere or set the stage so to speak. These graphics are not direct content and may not be considered essential, but they're essential in that they help frame what is going on.

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

For example; Alt text that is just like 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 get this content inside for those users.

Usually 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. The way you use this example is really a judgment call.

III. Content and Function

This is where 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 they don't know why the images exist. You have to determined precisely what function an image serves. Consider what it is about the image that's important to the page's intended audience.

Every graphic has a reason for standing on that page: since it either enhances the theme/ mood/ atmosphere or it is critical to what are the page is attempting to describe. Knowing what the look is perfect 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 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 have a couple more tools at your disposal for images.
First, in level 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're invisible and not shown like a "tooltip" when focus is received through the keyboard. (So much for device independence). So make use of the title attribute only for advisory information.
Second, the longdesc attribute points towards the URL of a complete description of an image. When the information found in an image is important to the concept of the page (i.e. some important content will be lost when the image was removed), a longer description compared to "alt" attribute can reasonably display should be used. It can offer rich, expressive documentation of a 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 the image...The aim is to use any period of description necessary to impart the facts from the graphic.

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

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

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

What's necessary and what's not depends a lot on the function of your image and it is context on the page.

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

Image Seo optimization Tips


Listed below are key steps in optimizing images:

Select a logical file name that reinforces the keywords. You can use hyphens in the file name to isolate the keyword, but avoid to exceeding two hyphens. Stay away from underscores like a word separator, like for example "brilliant-diamonds.jpg";

Label the file extension. For example, if the image internet search engine sees a ".jpg" (JPEG) file extension, it's likely to assume that the file is really a photo, and if it sees a ".gif" (GIF) file extension, it's going to assume that it is graphic;

Make sure that the written text at the image that's highly relevant to that image.
Again, do not lose an excellent chance to help your website with your images searching engines. Use these steps to rank better on all the engines and drive more traffic to your site TODAY.

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