The Ultimate Guide To Image SEO.

If you’ve ever gone to upload a blog or piece of content onto your website then you have likely thought to yourself ‘does this need an image’? Of course, the answer is always ‘Yes’. This is because not only can images make a huge difference to your content by bringing it to life and improving user experience, but they can also help your website’s SEO.

SEO (Search Engine Optimisation) has become one of the strongest areas of digital marketing with more and more businesses realising how important it is to establish a strong online presence. However, many businesses are missing out on a very powerful aspect; image SEO.

Therefore, if you think you have a good strategy in place but aren’t optimising your images, then you are really missing out!

Image SEO is a hugely neglected technique that can have a huge impact on a website overall, while also driving additional traffic. Research has found that over 20% of all web searches in the US happen on Google images. Therefore, if you aren’t optimising the visual content on your website, then you are potentially losing out on ranking opportunities.

So by learning more about image SEO, what it does and how you can utilise a few different tricks to make the most of it. Buckle up and be prepared to learn everything you need to know with our go-to guide about image SEO.

Whether you’re an SEO novice or simply need to expand your current strategy, we promise you’ll know exactly what you are doing by the end of it!

What Is Image SEO?

Image SEO refers to the process of optimising images on your website so that search engines can easily read and find the content. This is such an effective tool as it improves how your content ranks in Google and other search engines, while also improving your overall visibility.

There is a range of different techniques and elements that make up image SEO, including image size, type, optimisation of alt text, keywords in image file names, load times, and usage. This on-page SEO element is more often overlooked, however, it is just as important as other SEO techniques.

In fact, if your website has poor image SEO then you could even find that your page’s ability to rise in the index, gain links, and drive valuable organic traffic can be hindered considerably. But the good news is that image SEO really isn’t as difficult as you might think, and by following a few steps you can make sure that your images are fully optimised for search.

What You See:

Shiba Inu dog wearing a yellow hat

What Search Engines See:

img width=”996″ height=”771″

alt=”Shiba Inu dog wearing a yellow hat”

title=”cute shiba in hat”


class=”wp-image is-cached lazyloaded”

Always Use Images

We mentioned this briefly before, but we can’t stress enough how important it is that you use images in your online content. Uploading images to your website doesn’t take much more time or effort, but it can make a huge difference. Just look at how much value the image above added to that section!

We have all heard of the phrase that states “A picture is worth a thousand words”. And while this doesn’t necessarily apply to Googlebot, it does to your readers. Adding images to your content will considerably glow up long streams of text and help to engage your readers. Illustrating with images can also include charts and flow diagrams that can draw in readers and make your content more enticing.

Not just that, but with Google’s visions for the development of visual search, chances are, your site will get some additional traffic.

Example User Journey:

A female, aged 20-30 is looking for outfit inspiration, she goes onto Google Images and searches ‘red dress’.

If you are an e-commerce brand selling red dresses on your store, this is a prime opportunity to get in front of your ideal customer and open up a new stream of organic search engine revenue.

In this instance, using a visual search offers the user far more value and a better experience, but without image SEO, you simply will not show. Ensuring the visuals across your site are as optimised as possible is essential to maximise your visibility on organic search.

Selecting The Right Images

But it isn’t enough to simply include an image. You also need to select the right image. For example, it is always better if you can use original images that you have taken or created yourself, instead of just using stock photos. So if you are planning on creating a ‘Meet the Team’ page on your company website then take actual staff pictures instead of just adding cartoon images or using the picture from their LinkedIn.

And of course, it goes without saying that the image you are adding needs to have some relevance to the subject being discussed on the page. Is your blog talking about the importance of a strong digital marketing strategy? Well, don’t just add a picture of a cute dog, make an image give value to the user (even if it is a dog) such as we did!

If you use Yoast’s SEO content analysis plugin on WordPress and are just trying to get a green tick by adding a random and unrelated image, then it isn’t going to have the desired effect. Instead, any image should play a relevant and illustrative purpose for the content you are providing.

Similarly, it is also important that you try to place your images in the right areas. For example, if you are trying to rank for a particular image then try to place the image in the first half of the page. This is most effective near the top of content, but don’t let it feel forced or Google will know!

Know Your Keywords

Similarly, when you are optimising pieces of content or landing pages on your website, it is important that you do your research into keywords for optimising images too.

You likely already know the most popular search terms that visitors use to find your website, and if you know which keywords you rank for then this is a key indicator of what keywords to use for your images.

However, if you haven’t thought about this before and are unsure of what keywords to use, then we would say it is time to do some research. For this, you should use tools such as Google’s Keyword Planner, SEMRush or Ahrefs to establish what people are searching for. Being armed with the best keywords will provide you with the right basis to start your image SEO.

If you hop onto the performance report in Google Search Console and change the search type filter to images, you can see all the data for your website on Google images. This is a great place to start your image optimisation journey as you can make informed decisions and work out what areas of your site will benefit most and get the best return on investment.

the image performance report on google search console

For this e-commerce client that sells artificial wedding flowers, we optimised their images and saw a dramatic increase, generating 300 clicks and 209K impressions in just 3 months! We’re excited to see what will happen in another 3!

image search keywords report screenshot

Use SEO-Friendly Alt Text

Image alt text (alternative text) refers to the short written description of an image that explains what appears in the image. This written copy is shown if the image fails to load on a webpage.

Alt-text allows screen-reading tools to describe images to those who are visually impaired; making your website and content more accessible. We all know how important user experience is, and optimising your website’s image alt text can improve this considerably.

Alt text also helps search engines to crawl your web pages and rank your website easier. Therefore, it is important not only to add alt text to every image you use but also to include the SEO keyphrase that you are trying to rank that page for. By describing what’s in the image, you can help people and search engines make sense of its content so that they see it as important.

When writing image alt text there are a few things that you need to keep in mind:

  • While you want to describe the image you should also be specific and let the context guide you.
  • Alt text should also be kept to fewer than 125 characters.
  • Avoid cramming in keywords.
example of alt text

Here are some examples of good and bad alt texts:

Bad Example: <img scr=”kitten.jpg”/>

As you can see from this example, while the file name of the image reflects the content, the alt tag attribute is missing.

Bad Example: <img scr=”kitten.jpg” alt= “kitten cat baby cat feline kittens babies moggy ragdoll kittens ginger cat black cat Persian cat tabby kittens” />

However, in this example, while the alt text is present, it is stuffed with too many keywords which make it unclear and are not entirely relevant to the image.

Good Example: <img scr=”kitten.jpg” alt = “Black cat playing with toy”/>


Create Original Content

We mentioned this briefly earlier, but to drum it home some more we wanted to tell you again; make your own images! It is super important to create your own original images, and this doesn’t mean that you have to be a photography wizard. From designing your own infographics to making charts that visually explain the data you are referring to, there are lots of different ways that you can provide users with original and unique image content.

While we agree that using stock photos makes it a lot easier when making sure that your images are the right size, they aren’t as effective as using your own stuff. Most of the images that you will find on Shutterstock or Adobe Stock will be downloaded in site-friendly sizes. But curating your own graphs based on your own data that has been researched in-house will get more attention and help to do drive more traffic. This is because they are the types of images that will be shared on social media and may even be searched for with reverse image searches.

We all know that Google is user-centric and therefore it pays off for you to provide valuable and original content (and images) that will benefit your users. Therefore, you need to ensure that the images you use help users, provide valuable information, and create the best possible user experience.

But don’t worry if you aren’t a graphic designer. There are loads of easy-to-use tools such as Canva that can make creating in-house graphs, infographics and animated images so much simpler. Remember that this will help your brand stand out and make your content more shareable.

Add A Descriptive File Name

An image’s SEO begins with its name. You need to make it as clear as possible to the search engine (most likely Google) what an image is without it even having to ‘look’ at it. Therefore, by using the focus or primary key phrase in the image’s file name, you make it considerably easier for the search engine to engage.

If you take a look at the pictures file on your laptop then you may find images named ‘IMG36829.jpg’ or something similar.

But what does this tell search engines about the image’s content? Nothing!

Therefore, you should always rename the image to include a relevant and descriptive file name before uploading.

While this may involve a bit of extra work and may mean you have to spend some time organising your media library, changing the default image name to something more SEO-friendly can make a huge difference to your overall strategy.

Scale Images To Work With Your Website

User experience is an important part of SEO, and loading times have a considerable impact on the user experience your website offers. The faster the site, the easier it is for users to navigate and for search engines to crawl and index a page. One of the biggest challenges that your website loading time can face is images. And if you are uploading huge images that are displayed really small, then this can considerably impact your site’s load time.

This is because even if an image with a pixel size of 2500×1500 is featured at the reduced size of 250×150 pixels, then the entire size of the image has to be loaded before it will appear in full. Therefore, we recommend that you resize the image before uploading it depending on how you want it to be displayed.

The great news about using software such as WordPress is that it can do this for you after you have uploaded it by providing images in a range of different sizes. However, we would recommend that you consider the size of your images before you upload them, as even if WordPress provides you with different size images to choose from, the file size itself will not be optimised!

But overall, the correct image size will depend on the CMS that you are using, and the format of the page that you are uploading the image to. However, you can research the best practices for your CMS beforehand and find out what the optimal dimensions are. For example, Shopify recommends that square product photos should be 2048 x 2048 pixels.

In some cases, you may find that your CMS has automatically resized an image to go with your content to ensure that it fits nicely. While scaling and resizing images may sound like an arduous task, if you are downloading stock images then you should consider searching by the size that is geared specifically for your website or page. This will save you a considerable amount of time later on in the uploading process.

Reduce Image File Sizes

In an ideal world, all your images would be the right size, and in many cases they already are. However, there may be some times (such as those discussed above) where you will need to reduce image sizes. The good news? This isn’t as difficult as it sounds.

But first of all, why do we need to do this?

We all know that site speed is important for user experience. But it is also one of the biggest impacting factors on image SEO and has a huge say on how well a website ranks and gains traffic. In fact, you can pretty much say goodbye to keeping users on your site if it takes an age for them to navigate throughout the site and continue on your path to conversions.

Not only will they click off your site and head somewhere else for the information/product they were looking for. But also, Google will not look at your site favourably. This is where image compression can save the day!

If you are not already familiar, we recommend that you check out Google’s PageSpeed Insights for your website. You will see PageSpeed Insights popping up a few times within this image SEO guide, which is indicative of how important it is to your overall website’s SEO health.

pagespeed insights report screenshot

Looks like we have some Core Web Vitals work to do!

This super handy tool allows you to enter any URL from your website and provides you with in-depth feedback on all or any aspects that are hindering how fast your page is running. After a few of these assessments, you will soon see what elements are commonly affecting page speed.

One of the most common inhibitors of page speed is improperly sized images, which makes image compression one of the most crucial aspects of image SEO. And the good news is that PageSpeed Insights will actually report the images that are the biggest problem; allowing you to target them first. It also shows you much space you could save if you compress them. Cool, huh?

How do I compress images?

Using tools such as TinyPNG is a great way to quickly and easily compress images individually. But you may also be able to use plugins depending on the CMS you are using that allows you to compress images for your website in bulk to speed up the process.

If you are using WordPress, then the image optimisation plugin Smush would be our recommendation.

smush image compression screenshot

Give Lazy Loading A Try

While you may not be familiar with lazy loading, it can go a long way when it comes to increasing your page speed. Lazy loading is used by web developers so that objects like images or videos are only loaded at the point at which they are needed.

For example, if you have an image on your webpage that is only visible once the user has scrolled down, then a placeholder can be displayed instead and the site will lazy load the image once the user arrives there.

It is a great option if you are keen to improve the performance of your page and keep users on your site for longer.

However, we do recommend that you test your site with the new lazy loading feature before you send it to live so that any bugs can be identified. Otherwise, you may find that your image content is hidden and isn’t shown at all. And let’s face it, the only thing worse than slow content is no content.

Google also agrees that lazy loading can speed up loading on long pages, especially if you have many images below the fold. And we know it must be good if Google is endorsing it. If you check out Google’s PageSpeed Insights, you will see the lazy loading recommendations when trying to gather information on your page speed analysis.

Add Captions (Sometimes)

An image caption is a short text summary that accompanies an image on a webpage. A little bit like a caption that you see on social media or below a picture in a newspaper (who remembers those old fashioned printed newspapers?!). But you may be wondering what captions have to do with image SEO?

They are useful because they are used when scanning an article. If a user or search engine wants to quickly scan your webpage and see what the content is about, then they tend to scan images, headings and captions. Therefore, by adding captions you are enhancing the scanning process and making it easier for them.

Some research has even indicated that captions under images are read 30% more on average than the body of text itself. Therefore, if you don’t use them, or fail to use them correctly, then you could be missing out on the potential opportunity to engage with readers.

Every image needs a caption, right? Not necessarily. Images can serve a range of purposes within your webpage. To decide whether or not you should be adding a caption to an image you should decide whether your image is being used for illustrative purposes or as an element in your on-page SEO strategy.

Of course, it is important to remember that you don’t want to over-optimise anything. Therefore, we would recommend that you only add a caption to an image if it adds value to the reader. As with most things when it comes to SEO, think about the user first, and don’t do anything as just an image SEO box-ticking exercise.

But let’s see what Google has to say about captions…

“Google extracts information about the subject matter of the image from the content of the page, including captions and image titles.”

Therefore, we recommend that you add images close to the text that it is relevant to if you want to give Google a helping hand in determining what the image is.

Choose The Right Format

Unlike the perfect digital marketing agency (us, of course), when it comes to images the perfect format does not exist. Instead, it depends entirely on what type of image you are using and in what way you want to use it. Therefore, we will give you a few different tips and recommendations that should help:

  • If using larger images or illustrations we would recommend you choose a JPEG file format so that you can enjoy better results in clarity and colours.
  • PNG is the one for you if you want to keep a transparent background.
  • You can opt for an SVG format if you are using icons or logos and by using software such as JavaScript or CSS you can manage images within the SVG format. This includes resizing them without losing quality. However, without adding a Plugin, WordPress does not support these file types as they can cause security issues, so consult a web developer before using them!

If you’ve been checking out your website’s PageSpeed insight reports then you may have noticed that “serve images in next-gen formats” keeps popping up. This refers to formats that have superior compression and quality characteristics. This is in comparison to other formats such as JPEG and GIF.

By using these superior image formats that support additional and advanced features, less data is taken up but high-quality images aren’t sacrificed. This makes them a great option for use on the web.

Next-gen formats include JPG XR, WebP and JPEG 2000 and while they are not as well-known as JPG and PNG, they are definitely superior. Therefore, we would definitely recommend that you implement these formats to ensure less mobile data usage and quicker load times.

However, not all browsers support next-gen images yet, so ensure your CMS can handle serving the suitable previous/next-gen file type depending on the browser that the user is on.

Ensure Seamless Sharing With Open Graph Tags

If you aren’t familiar with Open Graph Tags then they refer to tags within the HTML of a web page that ensure images and descriptive snippets are displayed correctly when shared on social media, such as Facebook or Twitter.

Of course, the chances are that you want your online content to also work on social media, and for images to gain traction and attention so that they drive traffic back to your site. Otherwise, what is the point of them?

While in some cases you might search for open graph tags and find that they are already in there, if they aren’t in your source code then it is crucial that you add them. If they aren’t there then we recommend that you try doing a mock post on
your social media (Twitter or Facebook) to see how posts are populating and to check they are displaying correctly.

This may not sound like a big deal, but it is an aspect of image optimisation that you should definitely consider as it could be the difference between users seeing a one-off link in their feed, instead of a clickable and high-quality clickable image with a page description. As you would probably agree, the latter is much more likely to encourage users to click on your link and drive results.

But how do you implement Open Graph Tags?

Well once again, this will depend on the CMS that you are using. For example, if you are using WordPress then you will be able to find the Open Graph Tags fields within the Yoast plugin. (If you don’t have it already then we would recommend you start using it ASAP).

Our top tips for using the Yoast SEO plugin for Open Graph Tags:

  • Always use a large and high-quality image
  • Remember to preview your social media posts (only available in the Premium version) before posting
  • Are all your settings correct but the right image isn’t showing? Clear your Facebook cache and try again.
  • Twitter cards work in the same way as Open Graph Tags but for the Twitter platform.

Once you’ve added Open Graph Tags and are sure they are populating in the correct way, you should find your traffic-heavy webpages that offer the most value to your website, and ensure that they are shareable on social. Small changes such as this can have a considerable impact on your SEO and are the kind of image SEO techniques that you should be staying on top of.

Read more about Open Graph Tags in our ultimate guide.

Beware Of Copyrights

When adding images to your website, both for visual and SEO purposes you may be tempted to use any image that you find online. However, regardless of the images you use, be sure that there is no copyright conflict to avoid finding yourself in hot water.

We would recommend that you use stock photo providers that you know are legitimate. These include Shutterstock, DepositFiles and Getty. Some free stock image sites are Pexels and Unsplash. But ensure that you have a license to use these sites otherwise you could find yourself exposed.

Ensure Images Are Mobile-Friendly

Mobile optimisation has become an increasingly important aspect of SEO in recent years. Especially as Google now considers it when ranking websites. Plus, when done correctly, mobile SEO can boost your user engagement and provide you with more ranking power.

But how do you optimise images for mobile?

To do this, we recommend that you use the guidance of best practices provided by Google and create responsive images. In short, this means using images that will scale depending on the size of the site. So whether the user is visiting your site via mobile or desktop, it adjusts to the size of the viewing device. Sounds good, right?

In order for images to know the most appropriate image source to display, srcset and sizes attributes are required so that image content can be resized. This can include displaying images on small monitors, and high-resolution displays. When you consider that in 2021, mobile devices made up over 54% of all web page views around the world, it is vital to consider how you can appear to mobile viewers.

example of scalable images on mobile

Include Images In Your Sitemap

A sitemap is exactly what its name suggests. It is a file that contains a map of your entire site’s content. Here you can list the web pages so that Google and other search engines know how your site is organized.

They are a crucial part of SEO as they effectively tell search engines where to find everything and what all the pages of your site offer. By including every photo, video, meme, infographic or thumbnail in your site map, you can ensure that crawlers ‘find’ everything. This is especially useful if your website serves some images via JavaScript.

Of course, WordPress makes this even easier for you, as by using the Yoast or RankMath plugin, it will automatically add any visual content to your site map to save you having to upload it manually yourself. Talk about a time saver!

Our Image SEO Checklist

So we get that this guide has been super long, informative and provides you with the ultimate go-to guide to refer back to when developing your image SEO.

But to make it easier, here are our 10 actionable steps that you should keep in mind when working on your image SEO.

  1. Use original images
  2. Keep it relevant
  3. Pick a good accurate filename
  4. Include images in your sitemaps
  5. Use image alt text
  6. Add Open Graph Tags
  7. Use captions where necessary
  8. Try lazy loading
  9. Always be mobile-friendly
  10. Pick the right image size and format

If there is one thing we know for sure about the internet it is that the future is visual. From social media platforms pushing visual content to Google taking it into consideration when ranking web pages, it is definitely something you should pay attention to. There is no denying that the return on investment for image SEO is great and while it also promotes a good user experience, it is a win-win situation!

Hi, I’m Toby!

Author & Founder of Blank Slate Digital

I created Blank Slate Digital in 2020 with one simple goal in mind, to help grow small and medium-sized businesses.

In the past, I have worked on some of the biggest brands in the world and I want to leverage my experience and knowledge to provide a quality service.

founder of blank slate digital