While there has been an abundance of top-notch content written about off-site SEO, content marketing and local search optimization recently, there isn’t much on the subject of image SEO. This is surprising, given that your website images can now be used in more ways than ever to drive targeted traffic to your pages. Since we now have the ability to add detailed image information to XML sitemaps and further optimize images using hcard and schema.org microformats, it seems an appropriate time to take a better look at image SEO.
This guide uses local business examples, but most of these tips can be applied to image SEO for ecommerce, designer, recipe and other sites receiving large amounts of image referral traffic. Here are 14 tips to help you improve your conversion rates and use your existing images to generate more targeted referral traffic to your website.
1. Optimize your Image Alt Text
This is one of the most basic and well-known best practices for image optimization so I’ll put it at the top of the list. The alt text should be short but descriptive and relevant to other content on the page.
Example for a roofer in Springfield, Missouri targeting the search phrase “springfield roofer”:
The wrong way: <img src="CIMG00241.jpg" alt="">
The right way: <img src="springfield-roofer.jpg" alt="Springfield Roofer Homer Simpson">
2. Use High-Quality Images
From an SEO and user-centric standpoint it makes sense to use images that are sharp, well-lit, professional and visually appealing. Compare this photo with this photo taken from the “Meet our Doctors” pages on two different dental practice websites. Google can predict image quality quite accurately based on image dimensions, file format, color depth and color palette. Using high quality images can improve image search ranking and often provides a better user experience for website visitors.
3. Don’t Use Stock Images!
It’s truly astonishing how many businesses still use stock photos of models instead of adding real employee photographs . While the models in stock photos may be more attractive and the photography more eye-catching, they don’t provide any insight into who you are as a company. They don’t serve to build familiarity and don’t help your prospects put a face to the company name. Even if you don’t have a high-quality SLR camera or access to studio-quality lighting, consider replacing those cookie-cutter photos with real ones taken from your Facebook page or simply take some new ones.
Do an image search for “city + plumber” and see how many photos of real plumbers you can find. On- and off-line, clients appreciate honesty and transparency. To make matters worse, the stock images you use appear on hundreds of other websites which lead to huge quantities of duplicate content. Uniqueness helps in search rankings and Google’s search ranking algorithm doesn’t care how beautiful you are!
4. Specify the Width and Height of Images
This was essential in earlier versions of HTML if you wanted your images to display correctly. Although browsers have become much smarter and often don’t require these attributes, including them still gives you more precise control of the user experience and also helps Google properly index your images. Both Google and Bing give users the ability to filter their search by image size. If you have high-quality product photos that you want indexed, it’s best to let the search engines know that you have what they want.
<img src="topeka-wedding-dresses-vera-wang.jpg" alt="Vera Wang Wedding Dress" height="1600" width="1200">
5. Optimize your Images to Load Quickly
As mobile search continues to gain importance (it’s set to overtake desktop search by 2015), page and media optimized for fast downloading will be prioritized in the search results. If your images don’t need to be large, lower the resolution and trim off some of the fat. Not every mobile user has an iPhone 5 with a 4G connection. Older mobile operating systems, browsers and single-core cpus can serve to render larger photos painfully slowly.
This can also cause problems with crawling and indexing your content. Googlebot seems to weigh the benefit of indexing content with the resources required to do so when determining how it crawls and indexes the Web. If you have a lot of large images or your site isn’t crawled often, the larger images may not be indexed at all. You can check the load speed for individual pages, images, scripts and other media using a load time checker like this one by Pingdom. You can also reduce file sizes using an image optimizer like one by Dynamic Drive.
6. Keep File Names, Alt Text, and Captions Short but Descriptive
While Google’s search ranking algorithms are a better kept secret than the recipe for Coke, they’ve made no secret that relevance is extremely important. When naming your files and choosing appropriate alt text and captions, always keep the user in mind. Are your labels sufficiently descriptive enough to be useful to searchers? Have you given Google enough information to properly classify your images? Are your labels stuffed with keywords that could result in an over-optimization penalty?
7. Use (EXIF) Metadata for Image SEO
Google has access to the metadata stored in your image files. Choose a photo on your computer and take a look at the customizable image properties. Right-click on the file, select ‘Properties’, and click the ‘Details’ tab (on a Windows-based PC). Although Google hasn’t directly confirmed that it uses this EXIF (Exchangeable Image File Format) data in ranking non-textual content, it certainly seems likely. A hairless Matt Cutts alluded to this in one of his Webmaster Help videos here. Some of the customizable file fields to look at include: Title, Subject, Tags, Content, Authors, and Date Taken.
** Big time bonus for local SEO: Geotag your photos in the GPS properties section to give them better geographical relevance. If your camera doesn’t automatically tag them with latitude and longitude coordinates you can use a free online tool like GeoImgr. If you have photos of company events, satisfied customers, staff and store/office locations, you may want to add them to your website in a separate section and geotag them to better optimize your site as a whole.
8. Ensure Relevancy of Surrounding Content
According to many prominent industry experts, Google is moving towards a better semantic understanding of the Web. In order to improve the relevance of its search results, Google looks to related words, images, videos and links on a page to determine how likely a given page is to satisfy a user’s informational needs. Therefore, it’s beneficial to optimize images within the context of other content on the page. One quick and effective way of increasing relevancy is by adding image captions.
If you have a photo of your office, you could optimize it by placing it on a Contact or About page that includes your business name, contact details, and other regional information that relates to your services offered. Contextual relevancy along with other image optimization techniques helps Google more accurately identify and categorize your image.
9. Choose the Right Anchor Text
Anchor text has been one of the most important (and abused) of all Google’s search ranking variables. Manipulating your inbound link profile with an unnatural amount of keyword-loaded anchor text isn’t advisable. However, you can still improve the relevancy of your images by linking to them with accurate, descriptive anchor text internally. Don’t overdo it. Pagerank sculpting, or using too many internal links to sculpt the flow of Pagerank, not only worsens the user experience, it can also result in an over-optimization penalty down the road.
10. Put your Images in the Same Directory
If you have a lot of images on your site, it is useful to categorize them properly and keep related images in the same directory. For example, a jewelry shop with online product photos could maintain an image directory structure like:
This makes the source image URL more keyword-rich and it helps Google to crawl your images more efficiently and categorize them more accurately.
* Caution: If you are using WordPress and post your product images via a photo gallery plugin, your default directory structure could be much different. If you’re working on a new website, you may be able to use a more optimized structure like the one above.
If your site is older and uses another directory structure it may be a good idea to keep the structure as is. This is especially important if your product images and pages are already ranking well. Changing image locations can break links and could results in pages and images losing ranking.
11. Be Sure to Allow Image Access in Robots.txt
All of your image SEO will be for naught if Google can’t access your images. Check that your robots.txt file isn’t restricting access to your images or image directories:
This command prohibits all crawlers from accessing your image folder and any subfolders.
This command prohibits Googlebot from indexing any jpeg files.
Of course there are other ways to block Googlebot (and Bingbot) from accessing your images. This is another reason why it’s advisable to organize your images together.
12. Include your Images in the XML Sitemap
XML Sitemaps can now include a wide range of information on images and videos residing on your pages. The image-specific tags include:
<image:image> Encapsulates all information about an image object
<image:loc> The image URL
<image:title> The title of the image (optional)
<image:caption> The caption of the image (optional)
<image:license> The URL to the license for the image (optional) <image:geo_location> The geographic location of the image. (optional)
An example XML entry for a photo of the fictitious Tasty Bakery in Chicago, Il. follows:
<?xml version=“1.0? encoding=“UTF-8??>
<urlset xmlns=“http://www.sitemaps.org/schemas/sitemap/0.9 xmlns:image=“http://www.google.com/schemas/sitemap-image/1.1?>
<image:title>Tasty Bakery in Chicago</image:title>
<image:caption>Exterior shot of the Tasty Bakery in Chicago, Il.</image:caption> <image:geo_location>Chicago, Illinois</image:geo_location>
I haven’t been able to find any applications, plugins or widgets that will automatically generate XML entries with all these attributes. You would have to manually add these lines to your sitemap for further image SEO. Once your sitemap has been fully modified, remember to submit it using Google Webmaster Tools and Bing Webmaster Tools.
13. Add Applicable Microformats to Photos
Microformats are simple conventions that allow Google to better recognize and organize content on your pages. At this time, both hcard and schema.org are recognized by Google. Depending on the quantity of photos needing to be marked up and the amount of information that needs to be added, this can sometimes be a tedious job.
Fortunately there are some online generators for the most common microformat entities. An hcard (person) generator is available here and Raven Internet Marketing Tools has schema generators for different entities including: person, event and organization. The most common microformat for images is the hcard (person) format for marking up photos.
Here is an example vcard for Cookie Johnson, owner of the Tasty Bakery.
You can check your marked up data using Google’s Structured Data Testing Tool. Further documentation for the hcard format is available here and a full list of schema types can be found here.
14. Get Social with Your Photos
Build links directly to your images using your social networks. Use Pinterest to pin your images and then tweet the pins. Share your links to the photo URL on Facebook and Google+. This will get your photos indexed faster and adds inbound links with anchor text of your choice. Be sure to add some enticing titles and descriptions to get users to click on your links and actually view your images.
If you have a lot of product images on your site and receive some Facebook referral traffic, you may want to start using OpenGraph to optimize your images for Facebook search and sharing. Dana Lookadoo wrote a comprehensive post on the Moz blog about structured social sharing. Although it isn’t strictly about image sharing, it provides great information for optimizing your pages and images for social sharing.
It’s no secret that Google prioritizes rich media content over text in most cases. Adding relevant, easily-identifiable images to your site benefits both you and your users. Avoid keyword-stuffing and unnatural linking patterns. In addition to further Penguin algorithm updates, there are likely to be more spam-detecting additions to the ranking algorithm that will detect these violations of Google’s Webmaster Guidelines. So it’s best to keep things logical, relevant and focus on improving the user experience.