The Importance of the "alt" image attribute for SEO
The content of your website that the visitors see and the coding behind the page that search engine spiders read are important for search engine optimization. Anything you do to your website or any changes in your website will have a direct impact on how the search engines see your website.
"alt=" is the way to speak to search engine spiders and it should be descriptive about its context. Also it is compulsory if you want to write the right code and have your code validated. Specifically, ALT should be descriptive and it can also be a sentence. We cannot say that “alt” is a license for keyword stuffing but if used efficiently, it is the best way to get higher rankings for a keyword. Some webmasters and inexperienced SEO’s abuse the use of “alt” image attribute and try to stuff it with keywords thinking to achieve keyword density which is not that relevant for ranking as it used to be once. High keyword density, on some search engines may trigger span filters which causes penalty for your website’s ranking. Moreover, your site’s ranking will not be benefited form this tactic even without such a penalty.
The ALT attribute is a critical step but is often overlooked. This leads to the loss of opportunity to get better ranking in search engine results. An ALT attribute should never be used as a label for an image or descriptive. Many people use it in this fashion as it seems quiet natural to assume alternate text as a label or descriptive, but it is surely not.
Words used in an alt image attribute should be its text equivalent and deliver the similar information or serves the same purpose that the particular image would. The motive is to provide same purposeful information which a visual user would see. “Alt” image attribute is used to provide the descriptive text. Infact it is recommended to use descriptive text and human-readable caption around the image.
Alt attributes should always be added to the images. Alt is necessary for accessibility as well as for valid XHTML. Images only for decorative purpose should have an empty alt i.e. alt=”” or CSS background image so that users may not be bothered by uttering things like “spacer image”. Basically it is the function of the image that is to be conveyed. For example, any button image should not use the word ”button” in the alt text. It is necessary to determine alt text by context as the same image in a different context may require an entirely different alt text.
Basically the purpose of alt tag is to describe the image. The alt text is seen at the time of loading of an image, at the time of disabling images in a browser or a mobile device, or they use text browsers or the screen readers. In SEO, the importance of alt image attributes lies in boosting the ranking of your web page and if you choose to have images indexed; enhance your exposure by image search.