Search engines are sometimes described as ‘blind five year olds.” The reason for this is because Google (and other search engines) can’t ‘see’ images in the same way a human would. A search engine may be able to tell if your picture features a person, place, or thing, but the context is much more difficult. Search engines must rely more heavily on the words associated with the image in order to identify the content. So it stands to reason that we give search engines a helping hand by describing our images thoroughly. One way of doing this is by properly tagging images with relevant keywords. Google’s web crawlers may not be able to tell what’s going on in your images, but they can read any text associated with the images. This includes the file name, alt text, title text, captions, and text surrounding the image. We can use these attributes to help search engines “see” what our images contain.
Why optimize your images?
When you optimize your images, it will be easier for search engines to understand your site and send good traffic your way. This can give you a competitive advantage over competitors who never take the time to properly tag and optimize their images. Also, properly optimizing your images makes for a better user experience and will make your customers happy.
The power of originality
Before I get to deeply into how to optimize your images, I’d like to emphasize the importance of originality and quality. If you really want to get the most mileage from your images, original, high quality images (that are not found anywhere else on the web) will get you the most mileage. Search engines can usually tell when an image is an exact replica of another image. Google will usually only feature one version of an pic in image search results. So using original artwork or photographs is ideal–even if it isn’t always possible.
Origins of image tagging
The original intention of image tags known as “alt text” was to provide text when the image cannot be displayed–often because of speed or bandwidth issues. Alt text has also become valuable for both vision-impaired people using screen reading technology and for search engines. The fact that it’s useful to search engines means that optimizing your image tags can bring can bring you more qualified traffic. Just remember: It’s important to satisfy all the criteria above. If you just stuff your alt tags with keywords it will make for a bad user experience and could cause penalties from search engines.
When you optimize your images, it will become easier to find your content in Google’s Image Search and other image search engines. Image search engines can bring additional relevant traffic to your site. You may find that there is somewhat less competition in image searches. Web masters often get lazy when tagging their images–which means less competition. Use your competitors laziness to your own advantage and make sure to properly tag yours. Also, people tend to spend more time browsing and scrolling through images then they do when looking at web page results, so ranking on the second or third page has more value in image searches than regular search.
An additional advantage of being featured in image search engines, is that there is an increased likelihood that your images will be discovered and shared on image sharing sites like Pinterest. In some cases you may even want to unobtrusively add your website URL to your images so that people can trace the image back to your site.
Keyword research is a quick and easy way to find popular keywords to tag your images with. My advice is to make sure that your keywords describe and enhance your image as a first priority. Then use Google’s keyword planner tool (you need to create an Adwords account to use it) to find the best and most popular word choice and phrasing. In my opinion it’s far better to choose a keyword phrase with low traffic but high relevance than a keyword phrase with high-traffic and low relevance. In other words, pick keywords that relate to your image.
How to tag your images
There are three primary ways to describe your image for Google: file name, alt tags, and title tags. Image captions can also be used to describe an image–though Google has never specifically said that image captions affect rank, but it certainly won’t hurt if you use them correctly. For this reason I’ll add them to the list.
Note: When using a CMS like WordPress you can usually enter the title and alt tags during the upload process without altering any code, but knowing a little basic HTML won’t hurt either
Before you upload your image, make sure to name your image using dashes between each word. Usually this is as easy as clicking “Save As” in your image program or editing the file name from your desktop.
Don’t stringyourwordstogether or use_underscores. Dashes help Google understand the breaks between words.
The title tag is not required for images, but it doesn’t hurt to use it to add some additional copy–especially if it’s useful to the viewer. If your image is also a link, the title tag is probably more appropriately associated with the link and not the image. When writing the title tag for a link, think of where the link is going or what it does when you click it. The copy should inform the user.
Note: Similar to the alt tag, when you hover over a link or image which contains a title tag, the text will appear (known as a tool tip). Also, the title tag will usually trump the alt tag if you include both.
HTML example (just image): <img src=”www.url.com/person-doing-jumping-jacks.jpg” title=”Jumping jacks” />
HTML example (image and link): <a href=”http://url.com” title=”jumping jack article”><img src=”www.url.com/person-doing-jumping-jacks.jpg”></a>
The alt tag is an opportunity to describe your image for the sight-impaired (including Google). It is also used by Google Image Search. So be sure to enter something descriptive for your alt tag.
ex: Alt: Performing jumping jacks on the beach
HTML example (image and link): <a href=”http://url.com” title=”jumping jack article”><img src=”www.url.com/person-doing-jumping-jacks.jpg” alt=”Performing jumping jacks on the beach”></a>
Sometimes images need a bit of a description–so that visitors have additional context. When you choose to use a caption, make sure that it’s useful to the end-user first and promotes your keywords second.
Let’s say we have a pic of a delicious pie that you sell in your bakery. We could add the caption=“Jamie is an international jumping jack champion.” A caption like this adds value because it communicates a bit more about the picture (the name of the person featured in it) but it also ads a useful keyword phrase: “jumping jack champion”
Adding captions in WordPress is as simple as typing the caption into the caption field. The second simplest way is to use HTML5, like this:
<a href=”http://url.com” title=”jumping jack article”><img src=”www.url.com/person-doing-jumping-jacks.jpg” alt=”Performing jumping jacks on the beach”></a>
<figcaption>Jamie is an international jumping jack champion</figcaption>
The text surrounding an image
The text surrounding an image can also give search engines an idea of what is contained in your picture. So if it makes sense to describe your image in this way, you can further your advantage.
Image size considerations
Another factor to consider is the file size of your image. Large image files are slow to load and can cause a poor user experience, but highly compressed images (smaller file size) won’t rank well in image search results because users are looking for higher quality images. It’s important to strike a careful balance. If there are many images on your page, it may be best to compress them to increase page load speed. If you are featuring just a few images on a given page and you think the image in question will bring you traffic from an image search–use less compression. I usually try to keep my images under 100kb (this may not be possible for large backgrounds and banners). If you use WordPress, there is a great plugin called Smushit.it that will help you reduce the file size of your images. You can also reduce file size using most image editors like Photoshop. Pixlr.com is a free web app that also works great.
Do you have any image optimization tips? Let me know in the comment below!