Optimizing for image search can be a smart strategy for many search
marketers. Even if you’re working on a site that you don’t feel truly
lends itself to an image optimization strategy, you may be able to
leverage images or photos for SEO.
However, we should note that for some sites, there may not be a lot
to gain here. Some e-tailers report poor conversion on image search
traffic, and lots of the people coming in appear to be focused on stealing
their images. You need to weigh the benefit of image search capability
against the costs and other opportunities for SEO on your site.
Nonetheless, many sites do very well with image search.
A significant amount of traffic can come from image search, and the
number of people competing effectively for that traffic is much lower than
it is in general web search. Industries that don’t immediately seem to
provide compelling subjects for images may enjoy greater potential in this
area, because the competition might never clue in to the advantages of
integrating images into their sites and into an overall search marketing
There are a few different ways that image search optimization can
help to improve traffic and conversions for your site:
- Subtle reputation management
Images of your products/services/facility assist consumers
during the research phase of their shopping, and lend an implicit
message of openness/forthrightness to your business. Providing
generous numbers of images says you don’t have anything to hide, and
will improve consumer confidence in your company, increasing the
chances that they’ll select you to do business with.
- Shopping via image search results
Increasingly, consumers are searching for products via image
search engines because they can rapidly find what they are seeking
without having to dig through promotion-laden websites. If your
products can be found in the image search engine, you have an
improved chance of being found by those people. With no pictures,
there’s zero chance of being found in image search.
- Increase your chances of showing up more frequently in Universal
Performing image search optimization improves your chances of
showing up in additional positions on the main search results pages
as Universal Search pulls image search content into the main SERPs
for some keyword search terms.
- Empower others to promote you
If you have a flexible enough organization and you hold the
legal copyrights to your images, you can allow others to take and
reuse the images in return for promotion of your
1. Image Optimization Tips
Unlike normal web pages, which are often rich with text content,
image search is much more difficult for search engines to perform. The
image itself provides few clues to the content within it. Although
search engines are experimenting with techniques such as optical
character recognition (OCR) to read text content within images, most
images don’t have any text to read. Search engines are also making use
of facial recognition software to be able to determine when an image is
of a face versus a body, or something else entirely.
However, although these types of technologies are very useful,
they are limited in terms of what they can do. For that reason, success
in image search optimization depends on using all the signals available
to you to increase the search engines’ confidence in the content of an
This certainly includes the basic SEO techniques we have discussed
in this book. The web page’s title tag, the H1 heading tag, the on-page
content, and links to the page are all factors in image ranking. For
example, if you have a single image on a page and it is a picture of the
Golden Gate Bridge, and the title, heading tag, and page content all
support that, the search engines’ confidence in the content of the image
increases. The same is true if you have 10 images on a page of many
different bridges, and that is reinforced by the title, heading tag, and
content. Consistency of content and theme is important in all of SEO,
and it is especially critical in image SEO.
You should give particular emphasis to the text immediately
preceding and following the image as well. This is what the user most
closely associates with the image, and the search engine will view it
the same way. A descriptive caption underneath the image is
You can do a number of things to further optimize your images.
Here are the most important things you can do:
Make sure the image filename or IMG
SRC string contains your primary keyword. If it is a
picture of Abe Lincoln, name the file abe-lincoln.jpg and/or have the SRC URL string contain it, as in
Always use the image alt
attribute. The alt attribute
helps the vision-impaired to understand your site, and search
engines use it to better understand what your images are about.
Recent research by the authors indicates that this feature is still
not used for lots of sites’ images, and that many sites have tried
to use it with invalid HTML. Make sure the alt parameter is valid, as in this
<img alt="Abe Lincoln" src="http://example.com/abe-lincoln.jpg"/>
Use the quotes if you have spaces in the text string of the
alt content! Sites that have
invalid IMG tags frequently drop
a few words without quotes into the IMGalt content; with no quotes, all
terms after the first word would be lost, if any would be used at
all. tag when they were intended for the
Avoid query strings for IMG
SRCs just as you should for page URLs. Or, if you must use
URLs that include query strings, use only two or three parameters.
Consider rewriting the query strings in the URLs so that they do not
contain an excessive number of parameters, which will cause spiders
to refuse to crawl the link. Note that Google claims to no longer
have problems with these types of situations, but it is better to be
safe than sorry, and other search engines have been less clear as to
whether this is still an issue for them.
Use good-quality pictures, which will read well when shown in
thumbnail format. Good contrast is typically the key here.
Lower-contrast images are visually harder to read, and it is common
sense that if the thumbnail image doesn’t look good, it will not
invite a click.
Do not save images as graphics files with embedded
thumbnails—turn this feature off in Photoshop and other image
editing software. Search engines may copy your image, reduce it in
size, save it in compressed format, and deliver up a thumbnail of it
for their results pages. An embedded thumbnail can wreak havoc with
some compression software, and it increases your file size slightly,
so just leave that feature turned off.
Don’t store the image in a sidebar column with your ads or
inside the header/footer navigation elements; otherwise, the engine
algorithms will ignore the image as irrelevant, just as they ignore
page decor and navigation graphics.
Have a proper copyright license! You need to have a proper
license to display the images found on your site so that you don’t
get sued. Be careful about trying to use images from Wikimedia
Commons or other public stock photo sites since you cannot
be sure that those images really are in the public domain.
If you are using images that may also be displayed on other
websites, store/display them at different sizes from how they were
provided to you. Don’t change only their HTML IMG tag height/width parameters; reduce
the size of the images or increase or decrease their compression and
then resave them so that they have different file sizes.
Consider adding a watermark with your site URL to the image.
This can bring traffic to your site, and it also discourages people
from stealing your images.
Also, try altering the aspect ratio of the images a little
bit—that is, make sure the height-to-width ratio of the images is
different from images on other sites. You can do this by slicing a
few pixels off the height or width of the graphic and resaving it.
You need to change the file sizes and aspect ratios only if you are
redisplaying image files that may also be found on other websites.
This is particularly the case for licensed content, such as movie
graphics, news article graphics, affiliated content, and
manufacturer product images.
By changing the image files somewhat, you will help to ensure
that the search engines perceive your content as being sufficiently
original, instead of throwing it out of the SERPs after hitting a
duplicate content filter.
You need to ensure that your server configuration allows your
site’s images to be displayed when called from web pages on other
domains. Some system administrators have disabled this to keep
people from displaying their images on other sites, and this could
cause problems if you want your images displayed in search engine
image search results pages. Likewise, make sure that your robots.txt file does not block the
crawlers from accessing your image file directories.
If it is a fit for your business, specify that others are free
to use your images for online display as long as they link back to
your website from a credit line below the image or adjacent to the
image where they display your copyright notice. Enabling others to
use your photos invites more promotional attention when people wish
to write about you in blogs or in news articles.