Search Engine Optimised Images


In the early days of the web images were typically small and of low quality. We all remember the little animated men at work icons that littered the web in its infancy.

However as users have moved from dial-up to broadband connections the, number, size and quality of images on the web have increased significantly.

Some facts about images

  • 100 billion images captured and made available online each year.
  • 750 million camera equipped mobile phones sold each year.
  • 100 million digital cameras sold each year.
Images are important to search. Increasingly important. Don't just take our word for it though.

"Image search makes up about 5.7% of all Google Searches and 5% of all search is image related"

R.J Pittman, Google Director of Product Management, Feb 2009

However very few websites are optimised to take advantage. A recent study we conducted of the top 20 websites in a particular industry (thought to have fairly advanced SEO) highlighted their optimisation in this area was poor at best.

So what can be done to capitalise on this free traffic?

Host / Domain

Images should be hosted under the relevant domain. We often see websites hosting images under a different domain. The relevance can be lost in these cases.

For the website the following should be avoided


Images should either be hosted within or under it, e.g.

Image Filename

Images should have meaningful filenames. Using an ID, e.g. SKU, is simply not good enough and does nothing to inform search engines about the contents of the image.

Filenames like the following all too common examples should be avoided

  • 112354_main.jpg
  • Method-01-2011-med.jpg
  • e9b8fb52-6c02-11e0-b36e-00144feab49a.img

Images should have meaningful filenames without overly long paths, e.g.

Don't forget to include location information if that is relevant too.

If a website is translated into multiple languages then so should the image filenames. This can prove a challenge for some systems though and will often require duplication of images unless a sophisticated dynamic imaging system is used.

Ideally you want to be able to change the filename of the image without having to re-upload the image although it is important that your image URLs cannot be tampered with, e.g.



Google has extended its Sitemap capabilities to include support for images. You are now able to specify, caption, title, geo location and license for each image.

It makes sense to use this new capability although Google does not guarantee to include your images.


Google uses a special crawler to crawl the web for images. To prevent Googlebot from indexing small images, e.g. search results images, rather than the large images you want them to index, you could sniff the UserAgent string and serve it the large image URL. That way Googlebot will not accidentally include any small images that are less valuable.

Site Speed

In April 2010 Google announced that it was adding site speed as a signal in their search ranking algorithms. Amazon has released research showing that every 100 ms increase in page load time decreased sales by 1%. These are both compelling reasons to improve site speed.

As images typically represent the vast majority of page weight they can have a significant impact on site speed.

Example taken from online jewellery store and by no means worst case!

There are several techniques to mitigate this

  • File size reduction
  • Intelligent caching
  • Delivery acceleration

It is not good enough to implement one or two of these techniques all should be implemented.


Websites with international users are often providing a poor user experience because they are not optimised to cope with the distance.

The distance problem

  • 40 to 80 ms from Europe to UK
  • 80 to 180 ms from USA to UK
  • 250 to 300 ms from Japan to UK
  • 300 to 350 ms from Australia to UK
  • 500 to 600 ms from China to UK

As stated above Amazon research shows that every 100 ms increase in page load time decreases sales by 1%.

We tested loading a designer shoe website from London and Sao Paulo. It took 8 seconds from London and just over 20 seconds from Sao Paulo. The situation is worse with China.

If you were in any doubt as to the purchasing power of these countries the follow table shows High Net Worth Individual data from 2010.

RankCountryPopulation worth > $1 millionGrowth Rate%
5United Kingdom454,0001.4


At its current growth rates India would easily have more HNWIs than the UK by 2018.

Endless Aisle

Prior to the Internet retailers were restricted by the location and floor space of their shops. This not only restricted who they could sell to but the products they could sell.

With the advent of the Internet these physical restrictions have largely been removed. Retailers may stock the top products in their stores but are able to offer the long tail of products online. Retailers are also able to offer categories of products that are complimentary to their brand that they wouldn't ordinarily sell in their physical stores or wish to stock in their warehouses.

Increasingly people are using search engines to find products rather than visiting sites directly. Long tail products increase your content and the likelihood that people using search engines will find your site.

Discontinued Products

Products that have been discontinued should not be removed from websites as there will likely be residual links and hence traffic to them. Visitors should be shown the discontinued product and offered one or more of the following

  • replacement product
  • products from the same category
  • products from the same brand
  • etc.


Using a Dynamic Imaging product you are able to optimise images (dimensions and/or file size) for different classes of devices, e.g. PC, smartphone, tablet, kiosk, ePoS, connected TV, etc., or even different device models.

For example you may serve a picture at 85% quality for a PC but serve it at 60% quality for smartphones. Whilst 60% may be unacceptable on a PC, users on smartphones will not notice and will appreciate the quicker download.

Search engines such as Google are now crawling websites with different mobile user agents to see if they find different content or mobile optimised content.


Pinterest is a virtual pinboard. Pinterest allows users to organize and share things they find on the web. Users can browse pinboards created by other people to discover new things and get inspiration from people who share their interests.

Pinterest is growing very quickly. Since May 2011 the total number of Unique Visitors has grown over 2,702%. Nearly 70% of users are female with 97% of Facebook fans being women. The age demographic is fairly evenly spread although 25-34 year olds are the biggest users.

Referral traffic from retailers increased from 0.98% to 3.83% in the last 6 months of 2011.

Pinterest Pin It Buttons can be added to your website quickly and easily.