8 Ways To Optimise SEO Images & Get More Visitors
Images are an essential part of every website. They make them prettier, help users to understand the content on a page, work as advertisements, and much more. That’s why you need to know the fundamentals of SEO images—they can be the difference between your images ranking highly and generating tons of traffic from Google, or your image languishing in the depths, never to be seen.
In this guide, we walk you through the basics of optimising your images for SEO, and provide eight crucial ways to get them working for you.
What are SEO images?
SEO images are simply regular images that have been optimised. It’s all about making sure your website images are presented in the best way possible for your two major audiences: the human visitors to your website and search engine bots.
Humans are visual creatures and one of the simplest ways to make a positive impression is to use relevant images that tell a digital story. The goal of SEO image optimisation is to help Google find, understand, and interpret your images as relevant to your target audience’s search query so they rank above your competitors’ images.
You can achieve this by:
- Making your images easy for Google to index with clear, precise, accurate names and descriptions
- Compressing large image sizes to ensure a fast user experience (no crazy-long page load times that make your users click the back button in frustration!)
- Lots of other ways we’ll explore
Why is SEO image optimisation important?
No matter what kind of website you run, whether it’s an ecommerce, information or lead generation website, SEO image optimisation is crucial. If you don’t publish your website images with optimisation in mind, you risk getting buried in the search results below competitors who have mastered this technique.
But why is it necessary? Google’s search bots may be smart little things, but they’re not yet intelligent enough to understand the content of an image without help. In fact, they must read the text associated with your image to decode what your image is and how it relates to your content or the topic of your page.
From enticing user click-throughs on Google images to reducing site load time, excellent SEO image optimisation will help set up your website for success.
A quick guide to image optimisation for SEO
Here are our eight methods for getting your website images working hard for your SEO:
1. Use WebP or SVG file formats
Load speed is a massive factor for SEO, especially on mobile devices. So the file size of your images should be as small as possible, and the best way to achieve this is with the two “lightest” image formats: WebP, and SVG.
WebP is a relatively new format that was created by Google as a replacement for the JPEG, PNG, and GIF formats. It allows incredibly small file sizes (sometimes up to 10x smaller than other formats) without any loss of quality, and given that images are usually the biggest things to be loaded on web pages, they can turn a slow-loading page into a fast one.
Although this format has been around since 2010, the major web browsers have only recently started supporting it, so it can start being put to use. Some design apps like Photoshop may not allow you export as WebP by default, but you can find lots of free WebP converters online that do it for you. It’s an extra step in the process, but a potentially big one for SEO.
WebP should be your format of choice for pretty much every image that isn’t an illustration. If you do have an image that has been illustrated by a graphic designer—like a logo, a geometric design, or something else that is typically created in Adobe Illustrator—the best format to use is SVG. Because illustrations are essentially a series of intersecting lines that are filled with colour, this format saves the image with mathematical coordinates, which creates an extremely low file size. It also means the image can be blown up to an unimaginably huge size without losing any quality.
2. Use appropriate image dimensions
Another excellent way to reduce the file size of your images is by setting them to the correct dimensions for their use. For example, if you’ve downloaded images to use in your blog, and your blog is 800px wide, the image should also be 800px wide. Every unnecessary pixel in an image is a pixel that slows down the load speed for the page, and potentially affects your SEO. On the other hand, if the image is too small for its use, it will need to be increased in size to fit into its proper space, which will make the image seem blurry and unprofessional.
So when you’re saving or editing images, be sure to get the width and height for their space on the webpage. This can really speed things up.
3. Find a good balance for image quality
The final thing that affects the file size of an image is its quality, which can be chosen when saving, exporting, or editing the image in a program like Photoshop or Apple’s Preview. The trick here is to find a quality that still looks good, but isn’t too big a file size. In Photoshop, you can select different qualities and see the effect that it has on the file size, and try to find a balance that works.
4. Include keywords in your image’s file names (SEO image naming convention)
Your SEO image naming convention is also extremely important. You’ll need to create a descriptive, unique, keyword-rich file name that Google and other search engine bots can use to understand the subject matter of the image.
It may be tempting to cut corners and keep the standard file name your camera gives your photograph or use the default name of your downloaded stock photo. But these are little cardinal sins that make it harder for Google to serve your image to a relevant target audience. Think of your image file name as a short, accurate, keyword-rich description of the subject your image represents. Use precise, simple language and you’re good to go.
A good format to use is the following: target-keyword-for-page-image-description.webp. For a real life example, an image of a Google Analytics graph that appears on a blog about image optimisation might be named seo-image-optimisation-google-analytics-graph.webp.
This might mean venturing deep into your cavernous media library and changing all your old file names. But this little tweak to image names can make a surprisingly big difference when combined with the other simple tips included in this list.
5. Set image alt tags for SEO
You may not have noticed the little mysterious box called “alt attribute” or “alt text” when you look at your image’s properties. But this little piece of metadata plays an important role in helping both Google and your users read and interpret your image. That’s why it’s vital to set image alt tags for SEO.
What is alt text? Put simply, it’s the text you see when you hover your mouse cursor over an image. Like the image file name, search bots use it to identify an image’s content and decide how relevant it is to a user’s query. But there’s more: If a web browser has issues rendering an image, it will show this alt text to the user instead. When a visually impaired reader browses the web, the alt text is what the screen reader will read aloud to describe the image. This alt text is viewable in the cached text version of your page and can even act as the anchor text of an internal link when an image links to a different page on your website. As you can see, it’s super important to make it clear, relevant, and accurate.
So what is the best way to write alt text? Alt text should describe what the photo portrays in precise, concise detail, and should also include your target keywords for the page. For example, say you have a picture of an elephant on your website. An example of poorly written alt attribute might be:
<img src=”target-keywords-elephant.jpg” alt=”elephant”/>
A better example might read:
<img src=”target-keywords-elephant.jpg” alt=”elephant in a top hat riding a bicycle, target keywords”/>
6. Set HTML dimensions
Google released a major update to their algorithm last year—Core Web Vitals (CWV)—which rewards websites with a good user experience. One of the components of CWV is something called Cumulative Layout Shift (CLS), which is a fancy way of saying how much the page shifts around while loading.
As you’ve probably already experienced, a webpage that jumps around while loading is hard to interact with. A button that you wanted to tap on is in one place to begin with, but then leaps down the page after an advertising banner has finished loading. This sucks from a user’s point of view, and so Google rewards websites with a low CLS score.
How is this related to images? You can reduce CLS and stabilise the page by setting dimensions in the image’s HTML. By doing this, when the page is loading, a blank space is added where the image will appear, so when the image loads, the rest of the page doesn’t shift around. This can be a little tricky if you don’t know HTML, but it’s still very much achievable. This guide teaches you how to add HTML dimensions to images if you’d like to learn.
7. Use schema tags
Schema tags are something that Google and other search engines use to display “rich” results in their listings, like product images, blog images, event images, and lots more. If your page ranks highly, these rich results can appear at the very top of the page, and so can achieve an incredibly high CTR (click-through rate) and attract tons of visitors to your site.
Schema tags will need to be added by a developer, so they aren’t a simple thing to do. But they can be incredibly powerful when used correctly. They are also a great way to supplement your product tags to encourage rich results.
8. Create an image sitemap
You have two options: create a brand new sitemap for images, or add image information to an existing XML sitemap. Many CMSs like WordPress or Wix will create the sitemap automatically for you, so it’s worth looking into your own CMS to check whether this is the case. Alternatively, you’ll probably need a developer to create the sitemap for you.
A recap of your image SEO best practices
Image optimisation doesn’t need to be difficult. To tick the right boxes for Google, make sure you work through the image SEO best practices described above, and summarised below:
- Use WebP or SVG file formats to achieve the lowest file sizes possible
- Save your images to the correct dimensions for their use
- Find a good balance between image quality and file size
- Add keywords to your image file name
- Add keywords and descriptive text to your alt tags
- Set HTML dimensions for your images to reduce CLS
- Add schema tags to encourage rich results in search engines
- Create an image sitemap to allow search engines to find your images more easily
By following these steps for optimising SEO images, you will rank better in Google image search, provide your visitors with a superior, faster experience on your site, and set your website up for success.