Common SEO Issues: Image Optimization

May 01, 2020   |   Clock Icon 7 min read
We found that incorrect image optimization was one of the most common SEO issues. Here are some tips on optimizing your images for the web.
Close up of person writing on notepad

At Workshop Digital, we offer in-depth, 200-point SEO site audits that identify issues and opportunities on our client’s websites. We then use that information to help inform our on-going SEO strategies.

After we present our site audit findings, we provide a data file that lists all of the issues from our audit, and the priority we set for each issue. Recently, our SEO team analyzed 15 audit data files, which totaled more than 500 identified issues or opportunities. In addition to title tags—which our SEO Manager recently wrote about—we found that incorrect image optimization was one of the most common SEO issues.

Using Images on Your Website

Whether you’re a lifestyle blogger, writing an article for an online business, or working on a new webpage for a client’s website, chances are you’re going to wonder whether or not you should use an image.

Let me save you some time, the answer is always yes.

Images on websites help users further understand what you’re trying to communicate to them. Whether you’re giving lifestyle tips in a blog, or you’re trying to sell a product to a consumer, images give you a chance to help users visualize the content on your page.

While images are highly important for users, they’re equally as important for search engines and SEO efforts. When your images aren’t optimized for search engines, you are wasting a valuable SEO asset.

Image Optimization & SEO

There are several SEO advantages to optimizing your images for organic search:

  • Better user experience for users who utilize screen readers
  • Efficient page load times
  • Extra ranking opportunities

There are tons of ways to optimize your images for search engines, and many factors that go into an SEO-friendly image.

To keep things simple, below are a few common image mistakes that we see most often on our clients’ websites.

Picking the Correct Format

There are a lot of different image formats out there. Knowing which one is best for your website could make the difference between an optimized image or an image that is a burden to your website.

Put simply, there are two types of image formats that we see most often on websites:

  • JPEG: Image quality can sometimes be low, but typically don’t come with heavy file sizes.
  • PNG: Typically, PNGs are higher quality images. However, with that higher quality, comes large file size. Large file sizes can slow down your website and negatively affect the way search engines crawl your website.

Depending on the content of your image, you may want to choose one type over another. The general rule of thumb we like to follow is this: If it's a picture (think landscapes, animals, people, etc.), save the image as a JPEG. If the image is a graphic or a line drawing, save it as a PNG.

Another way to think of it is this: if an image has different colors, gradients, and textures, JPEG is the one for you. If it has sharp lines and/or clearly separated areas of flat colors and text, PNG is the better option.

Image Compression

I mentioned earlier that large file sizes can slow down your website, and that’s not good, but why does that matter to an SEO? Images play an important role in your site’s page load times, and the slower your website is, the more frustrated your users will be, and the less pages search engines will crawl on your site. And since page load time has been a Google ranking factor for more than a decade—and will continue to be an important ranking factor—now more than ever, it’s important to have a fast website.

Before you load images to your site’s CMS, make sure to compress them so that they are “lighter,” meaning their file size has been reduced. Keep in mind that this doesn’t affect the quality, appearance, or physical size of your image.

To compress your images, here are a few common tools that are widely used:

  • TinyPNG (and it’s free!)
  • GIMP (downloadable tool and also free)
  • For Wordpress sites, WP Smush is a fantastic plugin to install

So how do you know if an image is affecting your page load time? One of our favorite tools to use is Google’s PageSpeed Insights, which shows you specific components, including images, on your webpage that are slowing it down.

Image File Names

Search engine crawlers don’t have eyeballs, so they can’t see what images look like on your website. Image file names give you a chance to provide search engines with additional information and context for your images.

A common file name usually looks similar to this: “IMG_1234567.” For users, file name doesn’t usually matter, since they see the image not the file name. For search engines, the above file name is worthless and provides zero information.

Going into your CMS media library and changing image file names so that they are unique and descriptive can go a long way in helping the overall SEO value of your web pages. If I were to blog about my recent trip to Natural Bridge, VA, here’s how I would, and would not, name the image for the page:

Woman at Natural Bridge in Spring

Use Image Alt Text

Remember when I said that search engines can’t see images? That’s why it’s important to also create unique and descriptive image alt text.

Image alt text is an attribute that’s added to your image in the HTML code of your website. It’s the text that appears on a page when an image isn’t loading properly. There are several reasons why it’s important to have unique and descriptive alt text assigned to your images:

  • First and foremost, descriptive image alt text improves web accessibility. Users who might be visually impaired use screen readers to understand websites. If your alt text isn’t useful, users utilizing screen readers won’t understand what your image is.
  • If for some reason your image doesn’t load, alt text appears instead, so it’s important that text is descriptive.
  • Like image file names, image alt text provides search engines additional information on what your image is and how it relates to the content on your page.

Using the above image as a model, below is an example of what an image alt tag could look like:

<img src="natural-bridge-va.jpeg" alt="Woman at Natural Bridge in Spring">

Include Images in Your Sitemap

An XML Sitemap is essentially a text-based URL road map of your website that search engines can use to more easily index your website and the pages within it more intelligently and accurately. Having your images in your sitemap can help the chances of search engines crawling and indexing your images.

If the website is using WordPress, Yoast offers a great resource on how to make sure your images are added to your sitemap correctly.

Ready for Your SEO Site Audit?

Image optimization is only one of many things that can affect your website’s performance in organic search. We approach search engine optimization uniquely at Workshop Digital because websites are not one-size-fits-all. That’s why our strategies are customized and tailored to fit the needs of not only your website, but also your business.

Learn more about our SEO Site Audits today!

Portrait of Maggie Murray

Maggie Murray