SEO Best Practices: Image Optimization

SEO (search engine optimization) is the practice of preparing your website and other business related content to be presented to and searched by Google and other search engines. When we think of SEO we typically think of content, or the written portion of a website, blog post or article. However, image optimization is just as important as they too are used in searches.

Adding an image to your digital written content helps your reader understand that content better. When we use the term image, it means anything from a photo, chart, graph or illustration right down to a video. However, it’s important to note that before your image can grab the attention of your viewers, it must be presented to them and this can be achieved through proper and thorough image optimization.

So what exactly do we mean when we say ‘image optimization’? Literally, it means reducing the files size as much as you can without sacrificing quality. This way your page load time remains fast, and we’ve already discussed how important page speed is. But it’s also very much about SEO; getting your image (product or content representation) to rank on Google and other search engines.

There are certain practices that we deem necessary when it comes to preparing your images for the highest SEO impact. In this post we’re going to take a look at what you should be doing for image optimization.

First and foremost choose your image wisely. It’s best to create or use your own imagery as much as possible. It conveys your brand, sets consistency and represents the topic of the page/post. Once your image is selected it’s time to get to work on optimization.

Preparing the Physical Image

File Type
There are three basic file types: .jpg, .gif and .png.

  • .JPG files have become the default image style. They can be considerably condensed providing quality images in small sizes.
  • .GIF files are lower quality than .jpg images and are used mainly for simple applications like icons and decorative accents that have few colors. .GIFs also support animation.
  • .PNG images are becoming a more popular alternative to .gifs. .PNG files support more complex images than .gifs.
      TIP: In most cases if you go with a .jpg you can’t lose. They provide the best quality at the smallest size.


File Name
Using your keyword in the file name of your image is a key factor in image optimization. Google recognizes this image as it relates to the content surrounding it.

Scale/File Size
As we’ve mentioned many times, page load speed is important and loading images is a big factor in page speed. Therefore, reduce the size of your images as much as possible. Scale the image to the size you want to show it.

Adding Image to Page/Post

A caption is the text that accompanies an image and is typically shown below the image on screen. It’s important to SEO as people use them to scan the page/article much like they do with content headers. Captions are not needed for every image, however. When determining if your image would benefit from a caption look at whether or not you want to use that particular image for SEO. In this case, think about how the reader benefits from the caption rather than just SEO.

Alt Attributes
An alt attribute is the text used to describe what the image is when a browser can’t properly render it. It ensures that no information or functionality is lost when the image isn’t shown. Adding appropriate alt attributes that include keywords to your images help your site rank better in search engines. This is also probably the best way for ecommerce products to show up in searches.

Site Maps
While it’s not necessary to include a separate image site map on your site, it does help search engines when your images are included in your page or post sitemaps.

Marketing Relevance is a full service marketing agency that can help you boost your SEO with proven results. Contact us to find out how we can help you. Call 847-259-7312 or visit our website.