The following post is meant as a guide so that you can use the information and links provided to develop your own in-house guide for optimizing your website and blog images.
Put simply Google wants your images to load as quickly as possible. Why? So that the user gets the best possible experience such as not waiting too long for an image to load.
You need to consider balancing image quality and size for optimal presentation. This simply means that there is no one best size, but you should present the image without taking away from its visual aesthetics when downsizing.
Image optimization varies for each site and the server.
Google tool to check optimization – http://developers.google.com/speed/pagespeed/insights/
Google’s recommendations on image optimization (including suggested tools) – https://developers.google.com/speed/docs/insights/OptimizeImages
Other optimizing tools as described on Bryan Eisenberg’s site – http://www.websitetestingtools.com/category/insightstools/usabilitytools/page-load-time-tools/image-optimization/
Good detailed view of image optimization as explained in a blog by Ryan Morben – http://www.beanstalk-inc.com/blog/2012/11/01/google-image-optimization-part-1/
The alt attribute is important in a situation where an image cannot be displayed, for some reason. It could be used by blind people using screen readers, or checked by search engine spiders to get an idea of what the image is about.
You can use up to 125 characters for alt text but on average try to stick to 4 to 6 words, although occasionally more or less are needed.
Do not use keywords intentionally but rather describe the image. For example, if you have an image of a car on the road “Car on a road” would suffice. Alternatively, if the car was obviously a particular make you could say “Mecedes Benz on a road”.
HTML code – <img src=”car-on-a-road.jpg” alt=”Car on a Road” />
A descriptive filename like “car-on-a-road.jpg” is obviously better than its native name like “wpd12345.jpg”. This helps Google understand the content of the image. If you have a product picture, you could use the generic product name and perhaps an action being performed in the image (e.g. serving-from-a-coffee-van.jpg).
Title Tags – Captions
Using a Title Tag on an image allows the tags text to be displayed when a cursor hovers over the image. There is no apparent weighting provided by Google, yet. I consider it good practice to include where possible as it enhances the visitor’s experience, and that is one point that Google has shown strong interest.
It also provides the opportunity to expand on the information being presented by your image. Consider the text in the context of what you would like a visitor to see if they paid particular interest to the image.
There is some validity in the argument that it improves the bounce rate by keeping a visitor on your site a fraction longer if they are looking for more information.
Unique vs Stock Photos
Unique photos are generally considered more important than stock photos. The reason is that stock photos could be used several times by different entities and this, in Googles view, would lower the potential of them ranking in the Search Engine Result Pages.
Basically using a unique, or your own image is best for ranking that image.
Relevancy – Page Copy
Placement of an image must be relevant to the page or blog post. There is no advantage of placing an image of an ant foraging for food on a website about petroleum, unless of cause, there is a clear correlation between the two subjects.
Google looks at the page, and if they see no relevancy, it is unlikely they will add any ranking value.
Yes, the Internet is evolving and standards are being developed as it matures into a more useful source of information and also as it becomes more effective in communicating that information.
Schema.org is considered a very good source for developing standards – http://schema.org/ImageObject
Image optimization is not easy but you will reap the benefits when used. Please feel free to discuss the above, we can only benefit from each other with relevant ideas and information.