Search Engine Optimisation for images is becoming more crucial in the market, due to many of the search engines offering image searches, the most popular potentially being Google Image search.

Web browsers who are looking for specific images now generally use an image search instead of the old method of entering a search term in the main search engine.

To fully SEO your images for a high placement in image searches, there are a few elements to keep in mind.

Getting images indexed in a search engine such as Google is a very slow process.  For example Google uses a bot that indexes image results which visits a website far less regularly than a standard spider.  It has been reported that if a Googlebot visits your website on a weekly basis, a Googlebot-image may only visit your site every 6 months.

An effective method of image search engine optimisation is to get into the habit of designing your page’s code for a blind person, who uses a screen reader to browse the web.  This should always be done as it is a W3C standard. 

An Image-bot can not see an image, it relies on it’s description to index it appropriately.  With this in mind, it is important that you do not attempt to SEO images that are used as template files or a background on your webpage as they may be mistaken for genuine images by the search engine.

Here are the key elements that will help to search engine optimise your images and image pages:

The Image Filename
Naming images with a logical name means that you are performing SEO on your images.  The filename should always describe the content of the image, a good tip is to use keywords.

ALT Tags
The ALT tag should be used to describe the image. For example, if the image is of a cat sleeping, the Alt tag should start with “a cat sleeping”. Then optimise that a little more (without being accused of spamming) by expanding the ALT tag to “Cat Sleeping in the living room of my house”.

Surrounding Text
Surrounding text should also be used where possible around images to enhance the images SEO and usability. The Alt tag describes an image for those who can’t see it, but for those who can use captions or ensure that the surrounding paragraph explains what the image is.

As always with effective search engine optimisation, if there are SEO do’s, there are SEO don’ts.

Dynamic Images:
Search engines will only index files that it thinks are images. For example, if a script is use to generate dynamic images, resulting in something like “image.php?file=new.jpg”, the Search Engine’s image-bot will consider this to be a php file and not an image.

Move Images:
When working on your website, always use a logical folder structure for images and don’t change it.  An image-bot may take 6 months before it visits a website, if images have been moved they will not be found in the search results pointing at an old and out of date location, resulting in the dreaded “file not found” message.