SEO For Images

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The images on your website, if properly optimised, can contribute to your business’s SEO campaign. There are a couple of reasons why.

Firstly, search engines can’t see your images like visitors to your site can see them. They have only the coding of your site to work with, and if that code doesn’t clearly detail (in text form) what your images are of, then they give you no credit for having them on your site. The credit on offer? Improved rankings, which comes virtue of relevant images adding to the overall relevance a particular page has to the keyword being targeted, and relevance being a key factor in search engine algorithms.

Secondly, most search engines have an option that allows people to search only for images. By doing SEO for your images, you increase the likelihood of the images themselves (rather than just the page they’re on) ranking well in search engines. Traffic from image searches is unlikely to directly convert to sales, however, it builds brand awareness and can result in more backlinks to your site – if you allow people who find your images to use them in return for linking to your site.

So, what factors need to be considered as part of the image SEO process?

Image File Type & Size

The speed at which a webpage loads is known to be one of the factors that Google uses as part of their ranking algorithm, and each image that you have on a page on your site will slow down the speed at which that page loads. Therefore, it’s important to keep the size of image files to a minimum. By resizing an image, and saving it in the appropriate format, you can make the file size literally hundreds of times smaller, with only a slight compromise on the quality of it – most visitors won’t even be able to notice the difference.

You should aim to keep the dimensions of your images within 640×480 pixels and to save images in either JPEG or PNG format – formats which automatically compress the original file size. If you have bigger images, or images in other formats, then manually resize and convert them using an image editing program (such as Photoshop or GIMP). If your image editing software has some kind of “Save For Web” option then you should use that also, as it will further reduce the size of the file.

Image File Name

The name that you give an image file is included in the coding of the webpage that it’s displayed on, and search engines review every piece of that code when assessing the relevance of the page to the keyword being targeted. A random file name, such as image13579.jpg, adds no relevance to the page, whereas a file name with the keyword in it does add relevance. You need to find the balance between adding relevance and keyword over-usage though.

Don’t name all of the images on a page like this – keyword1.jpg, keyword2.jpg, keyword3.jpg, etc., as it could be classed as keyword stuffing, which is an SEO tactic that search engines warn against. If you have several images on a page, then include the keyword in some, but not all, of the image file names. As a guideline, don’t include the keyword in more than 75% of the file names of the images on any given page. Also, for each image file name it’s recommended to:

  • Make it a few words long.
  • Use hyphens (-) between each word.
  • Leave out stop words (a, to, the, etc.).
Image Alt And Title Tags

Image alt and title tags are pieces of HTML code that allow you to provide a text description of an image. The text you write for the alt tag will only be seen by visitors to your site if, for some reason, the image itself can’t be displayed. The text you write for the title tag will only be seen by visitors to your site if they hover the cursor over the image. The purpose of these tags, therefore, particularly the image alt tag, is primarily for search engines, who use them, once again, when evaluating how relevant a webpage is to the keyword being searched for.

As with the image file name, to signal relevance, the keyword being targeted with the page the image is on should be included in the image alt and title tags. However, you shouldn’t use exactly the same text for the file name, title and alt text – variation is good in all aspects of SEO. You can use the keyword in a phrase or sentence, or use a synonym of it, to add some variation. Typically, the file name will be the shortest of the three and the alt text will be the longest.

Image SEO Examples

General example:

<img src=”file-name-including-keyword.jpg” title=”Title of the image including the keyword” alt=”Description of the image including the keyword”>

An image on a page that is trying to rank for ‘mortgage advice’:

<img src=”mortgage-advice.jpg” title=”We Give Reliable Mortgage Advice” alt=”Mortgage advice from a company that you can trust”>

An image on a page that is trying to rank for ‘cheap africa holidays’:

<img src=”book-africa-holiday.jpg” title=”Cheap Holidays In Africa” alt=”Find affordable holidays in Africa”>

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