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If the internet was a country, it would be the world’s 7th-largest polluter. For businesses that want to limit their environmental impact, a low-carbon website is a good place to make a tangible difference.

In this article we hope to raise awareness about sustainable web design and the impact our websites have on the environment. We’ll also explain how businesses can reduce their digital carbon emissions and take a more eco-friendly approach to operating online…

The environmental impact of the internet

Our digital activities have become so central to our lives that it’s easy to underestimate the impact they are having on the environment. How harmful can it be, for example, to quickly check our emails while we’re waiting for the bus, or to see what’s happening on social media while the kettle boils? It’s easy to think that because we’re just one person, doing one little thing online, we have no impact.

The problem is, we all think the same. And when more than half the world’s population – around 4.1 billion people – are using the internet, there is a massive collective impact on the environment. Each individual web page request is a small raindrop building into a gigantic sea.

This is a very real environmental problem that a lot of businesses simply aren’t even aware of.

How big is the average web page?

The average size of a web page has more than doubled over the past 10 years, growing from 810kb to 2.28MB.

The average web page size has more than doubled between 2013 and 2013, rising from 0.8MB to 2.3MB (Source: HTTP Archive).

As internet speeds get faster and the tools for producing high-quality content become more accessible, websites are getting bulkier. Because it no longer takes an age for big images to load, it’s become the norm for businesses to populate their pages with large graphics, big video files, and animations that cater to the decreasing attention spans of the average visitor.

On top of this, businesses are using more and more tracking scripts in a bid to trace visitor behaviour. But all this extra bulk is adding to page-load speeds, and the energy and resources it takes to load the average website has risen dramatically.

And while websites are getting bigger, the amount of carbon being generated by them is increasing too.

Learn more about the environmental impact of web tracking scripts

How much CO2 does a website create?

Digital carbon emissions are difficult to visualise; it’s not as if your mobile phone spits out pollution while you’re browsing the internet. Although in many ways it would be good if it did, because calculating the environmental impact of our online activities is actually really tricky to do.

That said, research carried out over the past few years has given us a much better idea of how we might be able to calculate the environmental impact of our websites.

The Website Carbon Calculator displaying the message that scores in the top 1% of pages tested.
The Website Carbon Calculator is one of many great tools for testing your website’s carbon emissions.

The Website Carbon Calculator is a handy tool for businesses looking to work out how much CO2 their website generates. Using data inputted to their site, the Website Carbon Calculator reckons the average website generates 1.76g of CO2 per page load.

That might not sound like much, but when you consider that over the course of a year, each of these ‘average’ pages might be loaded 1,000 times, that will add up to appoximately 20kg of CO2.

That is the equivalent of approximately ten loads of washing, washed in a washing machine and dried in a tumble dryer.

The good thing is that, while a website with a lot of page views can easily build up quite a large carbon footprint, it means that making even a small, positive change can add up to a big environmental saving.

Read more about this in our article How much carbon does a website produce?

What is a low-carbon website?

As of 2023, a low-carbon website is defined as one that emits less than 0.5g of carbon equivalent per page load. But according to online carbon calculator Website Carbon Calculator, the average website now produces 1.76g of CO2 per page load. Most websites have a long way to go in reducing their impact.

Because the bloating of web pages – and the increase in overall website size – is being caused primarily by the use of more images and videos, the key to reducing the amount of carbon being generated by your website is through more thoughtful and purposeful design.

A website that is designed to be low in carbon emissions will:

  • Load quickly to reduce the amount of energy required by the hosting server
  • Generate low carbon emissions when it loads, minimising the impact on the environment
  • Require a minimum amount of page loads – and therefore energy use – while still helping your visitors to do what they came to do

And if you’re looking for an example of a low-carbon website? You’re already looking at one – as a sustainable web design agency we like to lead by example and the Root Web Design Studio website generates averages less than 0.1g of CO2 per page.

View more examples of eco-friendly web design in our WordPress development gallery.

What are the benefits of sustainable web design?

Low-carbon websites are undeniably much better for the environment, but there are a whole host of other benefits that make website optimisation a good business decision too.

A fast-loading, high-quality and efficient website will:

  • Show up higher in search engines. Google in particular rewards fast-loading websites above their slower counterparts, making it easier for you to reach your audience.
  • Provide a better user experience for your visitors. Slow-loading websites are frustrating and can even drive visitors away. If you provide a positive experience for your visitors, you’ll increase the chances of them being able to do what they came to your website to do, whether that’s find information, make an enquiry or buy something.
  • Work better on mobile phones. If your business serves customers directly, over half your audience is likely to come to your website on a mobile phone. Providing a speedy page load for mobile users is essential, especially when signal can be sketchy.

What affects carbon production in websites?

The amount of carbon produced by a website is directly affected by its page load speed. In simple terms, the slower a website is – the longer it takes to load each page – the more work the server has to do, the more energy it uses, and the more carbon it generates.

Therefore, the faster a page loads, the less carbon it produces.

The three main things that affect page load speed are:

1. The number of files required to load the page

When speaking about websites, ‘files’ include everything from the images and fonts included on the page to the scripts and stylesheets used. Being thoughtful about what elements you include on the page means you can limit the number of files and increase the page load speed.

2. The size of those files

The bigger the files, the longer those files will take to load. Saving images at a convenient size and in an effective format (photos as .jpg, graphics on transparent backgrounds as .png and icons as .svg) will help to reduce the weight, and load time, of a page.

Compressing files can also help them to load more quickly by reducing their size. There are plenty of tools out there for helping you reduce the size of your files:

  • Images: Running image files through a tool like tinyPNG or EWWW Image Optimizer involves lossless compression, which means their size can be reduced without affecting the quality
  • SVG files: These can be compressed using a tool like SVGOMG
  • Text files: For text files such as Javascript or CSS, minification (removing unwanted and unnecessary characters of code) can help shave off further valuable kilobytes

Another thing to consider is that certain media types, such as video, are naturally much larger files than static images, so it’s important to be mindful – and purposeful – about where and how you use this type of content.

When designing a website that’s efficient and low-carbon, you should aim to have a minimum number of files, and they should be as small as possible.

3. the Quality of your hosting package

In addition to thoughtful website design and development, a quality hosting package will be able to help reduce the environmental impact of your website through additional compression and caching techniques. You can also choose one of the many hosting companies that are committed to using sustainable energy to power their operations, therby reducing the impact of your website even further.

You can check whether your hosting company uses green energy by running their name through the Green Web Foundation tool.

If your website is regularly accessed by global users, you might further benefit from using a Content Delivery Network. A CDN is designed to reduce the energy required to load a website by loading a copy of the site from a server located in the country from where it’s being accessed.

Learn more about choosing a good hosting package in our Sustainable web hosting guide.

Is my website environmentally friendly?

If you run an environmentally conscious business, you’ll probably want to be sure that you have an eco-friendly website.

Ecograder impact report scoring 100/100.
The Ecograder Impact Report. The Root Web Design Studio home page scores 100% hurray!

Online tools such as the Ecograder and Digital Beacon can give you a helpful overview of the current carbon output of your website each time it loads, so you’ll have a good baseline for making improvements.

It’s also worth considering how often your site is visited. Making a few small changes to a website that gets a lot of traffic can add up to some huge savings on carbon emissions over the course of a year. You’ll be able to find out how many visitors your website gets, along with which pages are the most popular, by reviewing your website analytics.

Learn more about website carbon testing in our article Tools for calculating your website’s CO2 emissions.

How do you make a low-carbon website?

There are plenty of ways your website can be designed to generate as few carbon emissions as possible, and they all have the added benefit of helping to improve user experience too.

These include:

  • Web development. Efficient back-end and front-end web development can help reduce a website’s carbon emissions by optimising the processes needed to load the site from the server. Less server time means less carbon produced, and a faster page load speed for visitors.
  • Graphics and design. Low-carbon websites don’t happen by accident – they need to be designed that way. Limiting the use of images, videos and fonts will reduce the number of files needed to load a page, and this will reduce the amount of carbon generated. Likewise, swapping .png graphics for more efficient vector graphics (.svg files) will help pages load faster without compromising on quality for the visitor.
  • Concise copywriting. Clear messaging means your visitors will find out what they need to know quickly, and spend less unnecessary time on your website. Think quality over quantity.
  • Sustainable web hosting. You can massively reduce the environmental impact of your website by having it run with a sustainable hosting company. These companies will generally use renewable or sustainable energy to run their servers and offices.
  • SEO. Ultimately, the most eco-friendly website is one that doesn’t load at all, so it’s important to focus on attracting only visitors who will find your content useful. Being conscious and considerate with your search engine optimisation strategy will help you connect with the right audience, not just a bigger one.

Read more about low-carbon website design in our article How do I make my website more eco-friendly?

More digital sustainability tips

Beyond optimising your website, there are lots of other ways you can reduce the digital carbon footprint of your businesses.

  • Reduce the number of emails you send, receive, and store
  • Tidy up your cloud backups and regularly delete any files you no longer need
  • Delete any online accounts that you don’t use
  • Minimise videoconferencing and use phone calls wherever possible
  • Download videos and audio files rather than streaming them

Remember, there’s only so much we can do as individual businesses. But by focussing on the small steps we can take, we can do our bit towards creating a much larger collective impact.

Read more about how you can minimise the impact your business has on the environment in our article Digital sustainability tips for businesses.


We hope this article has given you a good understanding of sustainable web design and why it’s so important. We have spoken about how:

  • The internet has a huge environmental impact, generating around 1 billion tonnes of greenhouse gases every year.
  • The average web page has grown in size from 1.2MB in 2014 to around 2.2MB in 2022, largely due to the use of often unnecessary images and videos.
  • The average website now produces 1.76g of CO2 per page load.
  • A low-carbon website is defined as one that produces 0.5g or less of CO2 per page load.
  • Low-carbon web design minimises the number and size of files required to load a page, thereby speeding up the load time.
  • Visitors to low-carbon websites benefit from quality over quantity, with fast-loading pages that are designed and written to help them do what they came to do, quickly.
  • Low-carbon websites rank higher in search engines and work better on mobile phones, helping businesses attract the right audience, not just a bigger one.
  • Sustainable hosting can make a big difference to your business’s digital carbon footprint.
  • Sustainable web design focuses on quality over quantity, making it good for you, good for business, good for visitors, and better for the planet.

Further reading

To learn more about digital sustainability and what you can do to reduce your website’s carbon emissions, check out the following resources:

beautiful websites,
rooted in good ethics

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