Image SEO – Website Image Optimisation

Images should be essential, whether you’re an amateur blogger or your write for the leading marketing magazine. An image can tell a thousand words and can make your article easier to read and understand. The reason that you are reading this article, however, is because images also contribute to your websites SEO and we’ll give you an in-depth explanation how to optimise all your images to improve your search engine ranking and how to use images for the best user experience. Let’s dive into Image SEO.

Why Images Are Essential in Posts

When used correctly, images help readers process and understand an article, can be used by illustrating data in a chart or just make an article/post more exciting. It’s recommended that every post should include pictures as visual search is getting increasingly more important, for more information about this, check out Google’s vision for the visual of search. Therefore using images not only make an article more appealing but also could provide you with an increase in traffic. If you have visual content, image SEO should be high on your agenda.
Google’s most recent interface for Image Search was released at the start of August 2019, with features such as filters, metadata and attribution, which shows that Google has increased knowledge about what is in an image and how it fits into the bigger picture.

Selecting the Best Photo to Use

Rather than stock photos, it’s always better to original photos rather than stock photos, for example, your team pictures should be your actual team, rather than everyone in your company looking like models. I’m not saying they don’t already.

The image that you choose should be relevant to the subject of the article and the area of the article it’s positioned. For example, I have used the photo that I took when I was travelling the east coast of Australia to demonstrate the importance of not using stock images and the fact you are reading about it now puts the image into context and is therefore relevant to the article. If you just choose any random photo to complete your SEO plugin’s content analysis, then you need to re-evaluate your SEO strategy. If you have a main image or an image you’d like to rank, then locate it at the top of the page.

Avoid Stock Photos

Even if you don’t have any original photos of your own, you can still avoid using stock photos, there are other ways to find appropriate photos online. As long as you attribute the original photographer, you can source good-quality images from  It’s important that you understand what Creative Commons license is attached to the image you are using – there are eight different license categories and not all images on Flickr can be used the same way.

Choosing photos that look genuine is important unless you took them yourself, which is always the best route, and steering clear of obvious stock photos is a must!

GIF’s are getting more and more popular but don’t go overboard, it can make your post harder to read as the movement of the image can distract the reader’s attention and slow down your pages load speed.

How to Optimise Images for SEO

Once you’ve found the optimum photo for your article or blog post, whether it be an illustration, chart or image – the next step is to optimise it for SEO for your website. Here is an Image SEO checklist:

  • File name optimisation
  • The correct format
  • Image display size
  • Responsive images
  • Compressed images

File Name Optimisation

The first thing to think about when it comes to image SEO is the file name. Your need Google and other search engines to know what is in the image with even looking at it. For example, the image is of a sunset in Thailand, then the file name should be “Thailand-beach-sunset.jpg, not the original file name such as “IMAG8482”. The main key phrase or keyword should come first at the beginning of the file name, as its the main subject of the image, for instance, Thailand.

GLO Thai Beach Sunset SEO Image Optimisation Example

The Correct Format

The correct format depends on the image and its application and therefore, there isn’t a best image format to always use. For instance, image formats are used for the following reasons:

  • JPEG – for larger photos or illustrations (it will give you good results in terms of colours and clarity with relatively small file size)
  • PNG – to preserve background transparency
  • WebP –  to produce high-quality results with smaller file sizes (you can use tools like Squoosh to convert your image into WebP)
  • SVG – for logos and icons (with help of CSS or JavaScript you can manage SVG images such as resizing them without loss of quality can check whether the format you intend to use is supported by the browsers or devices that the largest part of your target audience use. Now it’s time to resize and optimise your image.

Image Display Size

Images that you use have a major impact on your web pages loading times, especially when there isn’t any need for your image to be that large, for example, if your image is displayed at 250×150 pixels and you’re using an image with 2500×1500 pixels, your whole image still needs to be loaded. The image load time is very important when it comes to user experience and search engine optimisation.

It is important to resize the image to the size you want it to be displayed. WordPress actually helps by providing several different sizes of the image after upload that show depending on the display, however, this doesn’t mean to the file size is optimised as well, therefore you should have the file size as low as possible without being pixelated.

Responsive Images

Having responsive images is an essential factor for image SEO, however, WordPress has made this easy since it was updated to version 4.4, where the platform makes images responsive for you. If you’re not building you website with WordPress, then your images should have srcset attribute, which enables a different image to be should depending on the screen width, which is especially handy for mobile displays.

Compressed Images

It is important for the image file size is compressed to be as small as possible, for web page load speed, user experience and therefore SEO. The easiest way to reduce the size of the image whilst keeping it high quality is by using web tools such as JPEGmini, which can dramatically reduce image size and remove to EXIF (Exchangeable Image Format) data to reduce the file size even further. This is increasingly important in a world of retina screens.

We also recommend using other tools to compress images; ImageOptim, or

You can test your site with tools like Google PageSpeed or Pingdom.

Adding Images for Optimum SEO

It is very important to add your optimised image to content that is related to it. While Google and other search engines are getting increasingly skilled at recognising what is in an image, you should still provide as much context as possible and therefore fill in all the relevant information.

Image SEO – Captions

Image captions are important in an article as people usually tend to pick them up when skimming through a web page, as well as headings and images. The image caption is the text the accompanies an image stating what’s in the image. Image captions are good for SEO but you should avoid over optimising your webpages and only add a caption when it makes sense to the user’s journey to have one. Not every image needs a caption as they are often the image itself is self-explanatory.

Alt Text & Title Text for SEO

If for any reason the image can’t be displayed, the ‘Alt Text’ or ‘Alt Tag’, which is the descriptive text will be shown in its place. The reasons in which the image can’t be displayed is sometimes because the user has turned off images in their browser, such as Google Chrome or they are using a screen reader due to visual impairment, this ensures that no information is lost.

For search engine optimisation, be sure to add alt text to every image, so that both search engines and people can make sense what’s in the image. The Alt Text should include an SEO keyphrase for that page where appropriate.

Add Image Structured Data for SEO

Once you understand the method of schema markup, you can optimise your website in the search engine result pages (SERPs). Adding such structured data to your pages can help search engines display your images as rich results. Google can also add a badge to the images on your webpage, for example, if you have recipes on your site and add structured data to your images, Goggle can add a badge showing the images belongs to a recipe.

Image attribute is mandatory for SEO so that your images can be crawled and indexed.

XML Image Sitemaps for SEO

Google’s advice and is to include a number of images on the page or post sitemaps:

“You can use Google image extensions for sitemaps to give Google more information about the images available on your pages. Image sitemap information helps Google discover images that we might not otherwise find (such as images your site reaches with JavaScript code), and allows you to indicate images on your site that you want Google to crawl and index.”

Image SEO Summary

As you have seen from this article, image SEO is made up of several attributes. It is just as important to ensure that the image and its elements help towards a good user experience which in turn plays an important role in conversion, as it is for SEO. With Google getting smarter and smarter at recognising element in images, it wouldn’t be a good idea to try and hack the algorithm.

Here is a quick summary and checklist of what you’ve learnt from this post:

  • Use an appropriate image that compliments your content
  • Carefully choose a file name with keywords or phrases
  • Ensure image size matches displayed image
  • Use srcset attributes if possible
  • Reduce file size for faster loading
  • Add a caption only if it compliments user experience
  • Use image alt text. No need for a title text
  • Add structured data to your images
  • Count for images in your XML sitemaps
  • Provide all the context you can!

The WordPress plugin Yoast can help with SEO!