Image compression - why and how to do it?

It may be surprising, but according to statistics Google graphics are responsible for 22.6% of all searches and almost 63% of searches on Google. This is why Image SEO, i.e. all activities related to image optimisation. This is an integral part of SEO activities. If you take proper care of Image SEO, it will not only affect the user experience of your website, but also its speed and, ultimately, its visibility in Google search results. Image compression is one of the tasks that Image SEO performs. Find out what it is, how to perform it, and learn about the other steps that will bring you closer to search engine success.

Image SEO - what is it all about?

Before we get to the compression itself, it is worth looking at Image SEO as a whole. This is a set of techniques that makes it easier for robots to index and ensure that I can get visual material to rank high in Google Graphics results. 

Image SEO helps:

• generate traffic to the site (not only through ranking in Google Graphics, but also because it is part of the on-site SEO)
• gain a higher position in search results (often even above the regular organic results - as a Featured Snippet)
• increase the conversion rate (especially on e-commerce sites, where product images are key to the purchase decision)
• improve user experience (images help to engage users and break up large blocks of text for better readability)

How does Google Graphics work?

Google Graphics, a search engine for all kinds of image files, was launched in 2001. Since then, it has used various algorithms to find visual elements suitable for the queries typed in by users. 

Currently in 2022, it operates in three ways: 

• context - The search engine tries to identify the image from the surrounding text. If it matches the query and the user's intent, Google will display it in the results. So the more context you add to an image to help the user understand what the image represents, the more likely it is to rank highly
• reverse search - is a Google feature that allows you to upload an image and find similar visual elements or detailed information about it without typing keywords in the query field. Go to Google Graphics and upload your image or enter the address of the URL rank the images you wish to examine
• Google Lens - is an artificial intelligence-based technology that allows the user to scan an object with a smartphone camera and get more information about it

What activities are performed as part of Image SEO?

You already know how Google Graphics works and what Image SEO is. It's time to learn some techniques to improve the visibility of your content and increase your website traffic.

• optimisation image file names - You should do everything you can to help Google understand your images. This does not mean stuffing keywords into the file name. File names should be descriptive, simple and give robots clues to the subject matter of the image. For example, tiny-black-cat.jpg is a better name than IMG00022.JPG

• optimisation of alt attributes (alternative texts) - It is the alternative texts that the browser displays to users with screen readers or when there is a problem rendering the images and they cannot be loaded. When creating alternative texts, focus on making them useful and making appropriate use of keywords, not pushing them

• creation of an XML site map of images/graphics - This sitemap provides additional information about the images on the website. It is helpful for more accurate indexing of images in a Google Graphics search. Although you can include information about images in the main sitemap, a separate file helps to systematise them

• consider lazy loading - lazy loading involves loading only key resources at a given time. The browser does not download all of them from the server at once, but only the priority ones that are to be seen by the user

• add structural data - is information that helps search engines understand your website. Their implementation increases the chances of your images ending up in what are known as enhanced search engine results. Currently, Google supports structured data for products, films or recipes

• compress images!

Image compression - what does it involve?

Image compression is reduce the weight of an image without reducing its quality, or with a minimal reduction in quality (mostly imperceptible to the human eye). Of course, compression can vary in degree. The higher it is, the smaller the image size. It then takes up less space on the website, but also loses its detail.

How to compress images?

Images make up the lion's share of your site's weight. This means that compressing them can make a significant difference to your site's speed, and given its importance to Google and to your user experience - it's well worth the effort. If your site is based on WordPress, you can simplify your life by installing one of the plugins listed below, which will do all the work for you.

• Imagify - is a plug-in that allows you to perform compression at different levels (Normal, Aggressive and Ultra). It supports PNG, WebP, PDF, GIF and JPG formats. A limited free version and a pro version are available. It has an automatic resizing and optimisation function performed during file transfer.

• EWWW Image Optimizer - This plug-in, which is available in Polish, supports the most popular formats and has no restrictions on the size of image files to be compressed. As with Imagify, you can use the free version or purchase the more advanced pro version.
• Smush - This plug-in has a user-friendly interface and clearly presents the results of image compression. Available in free (limited to images under 1 MB) and pro versions. Also Polish language version.

You can also use external tools such as TinyJPG or Optimizilla.

Remember! Page loading speed is a Google ranking factor! Improve this indicator (thanks to compression, among other things) and get better rankings in the search results.