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 that images on your web site:
Images:. Use the alt attribute to provide descriptive text. Additionally, we recommend utilizing 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 can't see the images.
Many webmasters and inexperienced or unethical SEOs abuse the use of this attribute, trying to stuff it with keywords, looking to achieve a particular keyword density, which isn't as relevant for rankings now since it once was.
On the other hand, high keyword density can, on some search engines, trigger spam filters, which may result in 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 in a greater disadvantage. Screen readers are software-based tools that actually read aloud the contents of what is displayed on the screen. In browsing the net, the alt attributes of images are read aloud too.
Imagine hearing a paragraph of text which is followed by repetitions of numerous keywords. The page would be not even close to accessible, and, to put it bluntly, would be found quite annoying.
What exactly is an Alt attribute?
An ALT attribute should not be used as a description or a label for an image, though lots of people utilize it in that fashion. Although it might seem natural to assume that alternate text is really a label or perhaps 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 goal is to supply the same functional information that a visual user would see. The alt attribute text should function as a "stand in" in the event that the look itself 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 should be 'search' or 'find' not 'magnifying glass' or 'binoculars'.
If the image is supposed to convey the literal contents of the image, a description is suitable.
If it's meant to convey data, then that information is what's appropriate.
If it is meant to convey the use of 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 merely a decorative role in 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 things like "spacer image".
Remember that it is the function of the image we are attempting to convey. For example; any button images should not include the word "button" within the alt text. They ought to emphasize the action performed through the button.
Alt text should be based on context. 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's how it is going to be read with adaptive technologies like screen readers. Someone hearing your page should hardly remember that a graphic image can there be.
Please remember that using an alt attribute for each image is needed to meet the minimum WAI requirements, that are used since the benchmark for accessibility laws in UK and the rest of Europe. They are also necessary to meet "Section 508" accessibility requirements in the US.
It is important to categorize non-text content into three levels:
Content and Function
Eye-Candy are things that serve no purpose other than to create a site visually appealing/attractive and (in many cases) fulfill the marketing departments. There is no content value (though there may be value to a sighted user).
Never alt-ify eye-candy unless there is something there that will enhance the usability of the site for someone utilizing a non-visual user agent. Use a null alt attribute or background images in CSS for eye-candy.
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're important in they help frame what is going on.
Try to alt-ify the 2nd group as makes sense and is relevant. There may be times when doing so may be annoying or detrimental with other users. Then 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 instances. But sometimes, it's important to understand this content inside for all users.
Most times it depends on context. The same image in 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 is the actual content. Always alt-ify content and functional images. Title and long description attributes can also be in order.
The reason many authors can't understand why their alt text isn't working is they don't know why the pictures are there. You have to determined exactly what function a picture serves. Think about what it's concerning the image that's vital that you the page's intended audience.
Every graphic includes a reason behind being on that page: because it either enhances the theme/ mood/ atmosphere or it is critical to what the page is attempting to explain. Understanding what the look is perfect for makes alt text easier to write. And practice 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. An amount you say when encountering a specific image to create the page understandable to the listener?
Besides the alt attribute you've got 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're invisible and never shown as a "tooltip" when focus is received through the keyboard. (So much for device independence). So use the title attribute just for advisory information.
Second, the longdesc attribute points to the Link to a complete description of an image. When the information contained in a picture is essential towards the concept of the page (i.e. some important content would be lost when the image was removed), an extended description compared to "alt" attribute can reasonably display ought to be used. It may 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  states, "A longdesc is really a long description of an image...The aim is to use any length of description necessary to impart the details of the graphic.
It would not be remiss to hope that the long description conjures an image - the image - 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.
In many cases, you're better off just going with your gut instinct -- if it's not essential to incorporate it, and if you don't have a strong urge to do it, don't add that longdesc.
However, if it's necessary for the entire page to work, then you have to include the alt text (or title or longdesc).
What's necessary and what's not depends a lot about the function of the image and it is context about the page.
The same image may need alt text (or title or longdesc) in a single spot, but 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. But if the image provides content or adds functional information an alt would be required and maybe even a long description will be in order. In many cases this kind of thing is a judgement call.
Image Seo optimization Tips
Listed below are key stages in optimizing images:
Select a logical file name that reinforces the keywords. You can use hyphens within the file name to isolate the keyword, but avoid to exceeding two hyphens. Avoid using underscores like a word separator, like for example "brilliant-diamonds.jpg";
Label the file extension. For example, when the image search engine sees a ".jpg" (JPEG) file extension, it's going to assume that the file is really a photo, and if it sees a ".gif" (GIF) file extension, it's likely to assume that it is a graphic;
Ensure that the text nearby the image that's relevant to that image.
Again, do not lose a great chance to help your website together with your images in search engines. Use these steps to rank better on all of the engines and drive more traffic for your site TODAY.