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Biggest environmental savings come from good user experience 

Good user experience has a great impact on environmental sustainability. Always follow standards for good user experience since it, and especially shorter user journeys, have a big impact on reducing carbon emissions of digital services. When you plan user journeys to help your users achieve their goals efficiently, it automatically translates to reduced loading times. The more users a webpage has, the more important a streamlined experience becomes.  Keeping page amounts to a minimum is also crucial to reducing environmental impact. When users have to enter a new page, it also means the content or parts of it needs to be loaded again, which increases the amount of times data has to travel. Some of this can be controlled with good technical solutions. However, the biggest difference comes from using the least amount of pages in general.

If possible, make your content carbon-aware and try to help users understand what is digital sustainability. Let users know why certain decisions were made and how it helps the environment.

1. Follow standard practice for good user experience. This helps users be efficient and reduces the amount of clicks and searches.
2. Think of ways users can reach content faster. For example, onsite search features, redirects, good SEO practices and smart 404 pages
3. Try to minimise and streamline user journeys whenever possible.
4. Consider whether you are using pages for information that could be a section on an existing page.
5. Consider whether you have content which has an expiry date and how it can be removed later to reduce data amounts.
6. Design for accessibility. Accessible sites are also performance friendly, which means less energy consumption.

Make more eco-friendly choices with images

Using images requires an efficient strategy to reduce data amounts and energy consumption. Often an image can communicate more information than a thousand words, which is why images are very commonly used. However, images are usually the most common cause for big file sizes for digital content. When considering using an image, it is important to make sure that it is justifiable enough for the corresponding impact on nature. 

1. Optimise images for a smaller file size by using lossy compression styles.
2. The WebP format provides better compression rates than others.
3. If your image is vector-based, use the SVG file format instead of PNG. Unless your image is highly detailed.
4. Using smaller image dimensions allows you to load the image in a smaller file size.
5. Image details and colour contribute to file size. So consider using simpler imagery, shallow depth of field, reduced colour palettes, for example black and white images.

Make more eco-friendly choices with videos

Videos cause a lot of data transfer which requires energy. In fact, when videos are used as digital content, they are usually the biggest contributors to energy consumption on websites. Be mindful with your use of videos and add them only when they deliver genuine value for the user.

1. Always use compression to reduce file size.
2. Consider using short CSS animations instead of video.
3. Avoid using autoplay. Autoplaying videos use up unnecessary bandwidth, but they are also not accessible as they can be distracting.
4. Offer options to view compressed versions or by pass the video also in case of low-bandwidth.
5. Make sure users are watching the videos. For example, consider using A/B testing to help you know how and where it’s good to prioritise video.
6. When including a video which is muted, remove the audio track completely. The audio track is often empty, but still present and using bandwidth.
7. Remember that file formats matter. MP4 is generally efficient and delivers smaller files than animated GIF, and also provides better accessibility with features such as audio description tracks and captioning. While MP4 is still a much more universal file format for videos, consider whether you could use WebM for a smaller file size.

Make more eco-friendly choices with colours

Colours contribute to the energy consumption of screens, so there are a few things to consider. It has been tested that darker colours require less energy on OLED screens while white requires the most energy. Also, a notable finding was that blue pixels use 25% more energy than red or green. Being strategic is key and this doesn’t mean you need to use only dark mode. Adding darker shades on some key areas will reduce energy consumption levels.   

Make more eco-friendly choices with typography

Using a lot of different font weights and custom fonts can significantly increase the file sizes in use. It’s better to stay minimal in your typography choices. Also, by staying consistent and minimal you will also add to the readability and usability of your content. 

If you want to use custom typefaces, it pays off to be strategic about it. Consider using an eye-catching typeface on headings or menus, since they tend to add much more visual impact. Favouring system fonts will also save bandwidth, which makes them faster and more environmentally friendly alternatives.


The official Aalto fonts are Inter and Besley, both of which are open source. In digital channels, Inter is the font of choice.

Quick environmental sustainability checklist

Always aim for smaller file sizes with your assets. 

1. Use images and video wisely and be critical of whether you actually need them.
2. Use compression tools and consider alternative methods like using clever typography choices instead of images.
3. Prefer vector illustrations over images.
4. Be minimalistic with your use of typography.
5. Consider your contents end-of-life.


Follow standards for good user experience.

1. Minimise user journeys and page amount. Always consider whether your information could be a section on an existing page before creating a new page.
2. Make content easy to find and understand.


Consider the energy efficiency of your design choices.

1. Design for accessibility. Accessible sites are also performance friendly, which means less energy consumption.