How Your Website’s Popularity Might Be Impacting the Environment


When you’re busy running a business, the amount of carbon your operations create could well be the furthest thing from your mind – especially if you’re doing your bit for the environment elsewhere. But everything you and your business does, whether it’s sending emails, using Slack or calling clients over Zoom, produces its share of carbon emissions. Yep, even something as banal as sending your colleague dog memes can end up contributing to long-term climate change.

The same goes for websites, too. Large files, high-definition videos and massive images all contribute to the site’s total emissions. So, whilst a cutting-edge website is a boon for your business’ custom, it’s bad news for the environment.  

To dig a little deeper into the matter, we wanted to see which websites might be paying the price for their dense content, by looking at how many tonnes of CO2 they produce.

Below, you’ll find the results of our findings, along with some handy ways your business can start to minimise the number of emissions it creates through its website. Scroll down to see what we found out…

What did we do?

To carry out our investigation, we used data from SEMRush circa December 2021, gathering the average monthly sessions of ecommerce sites and then multiplied these sessions by the average CO2 emitted per site visit with the help of These calculations then gave us the average estimated emissions of each site per month.

We also used to calculate what CO2 emissions equated to in other energy usage.

Key Findings:

  • eBay is the UK site with the highest monthly emissions, producing 907.8 tonnes of CO2 every month
  • Despite it receiving more site traffic each month (~282 million), Amazon UK generates fewer CO2 emissions than eBay
  • When it comes to fashion, Next is the site that generates the most CO2 emissions (45.3 tonnes CO2 per month)
  • Marks and Spencer had the highest traffic of any fashion website (25,786,823 site visitors monthly) but only generated the third-highest volume of CO2 emissions (​​16 CO2 tonnes per month)
  • BBC Good Food took the food site top spot, producing the highest emissions (58.8 CO2 tonnes) in this category
  • Twitch was the gaming site with the highest emissions both in the UK and the world, creating 140.4 CO2 tonnes per month in the UK and 3,444.8 CO2 tonnes worldwide
  • In fact, Twitch’s is that popular its CO2 tonne emissions were over double the emissions of the Steam Community, the UK’s second highest game site
  • eBay US is the ecommerce site generating the most emissions monthly worldwide (1430.3 CO2 tonnes per month, roughly equivalent to 127,460 gallons of diesel being consumed
  • Macy’s is the world’s highest emitting fashion site, generating 276.9 tonnes of CO2 monthly

Top 5 Highest Emissions – Ecommerce Sites UK

UK ecommerce list graphic

Monthly Insights

  • eBay UK generates 907.8 tonnes of CO2 per month, roughly the equivalent of powering 150 homes’ electricity for one year
  • Amazon UK emits 397.9 tonnes of CO2 per month, which is equal to 40,618 gallons of petrol consumption in the same period of time
  • Currys generates 178.1 tonnes of CO2 each month, which is around the same amount of emissions that burning 178,580 pounds of coal would produce
  • eBay US emits 52.4 tonnes of CO2 from UK users, equal to keeping 5,782,463 smartphones juiced up
  • (B&Q) emits 46.7 tonnes of CO2, which is the same as 98.1 oils barrels being consumed

World Data

Top 5 Highest Emissions – Ecommerce Sites World

worldwide list graphic

Monthly Insights

  • eBay US generates 1,430.3 tonnes of CO2, roughly equal to the consumption of 127,460 gallons of diesel
  • Home Depot emits 1,167.2 tonnes of CO2, similar to 5.8 railcars’ worth of coal being burned
  • Walmart generates 1,105.9 tonnes of CO2, which is roughly the equivalent to 121 homes’ energy usage for a year
  • eBay UK generates 1,040.7 tonnes of CO2 worldwide, which is almost the same as charging 114,843,688 smartphones
  • Target emits 895.4 tonnes of CO2, an amount that’s equal to taking the car for a spin over a distance of 2,041,453 miles

How to reduce the carbon footprint of your website

So, what can you do to make sure your business’ website isn’t adding to the effects of climate change?

Obviously, reducing the amount of traffic to your site would be impractical – nobody wants to lose business, after all. Handily, there are a few useful things you can do to cut down on your site’s emissions without losing loyal customers, including the below:

  • A site with plenty of bells and whistles might look nice, but all that window dressing creates lots of emissions. Cutting down on the amount of data-intensive, energy-sapping imagery used across your site can help. You should also make sure that your site isn’t loading larger images than it needs to; make sure you know the dimensions of your website inside and out – otherwise you could be putting a strain on it. You can also reduce the file size of your imagery – without compromising on quality – with image compressing programs like TinyPNG, and use more efficient file formats such as WebP over JPEGs.
  • Are the videos on your site necessary and do they provide value to visitors? If so, be sure to turn auto-play off and keep them as brief as you can to avoid clogging up the environment with hazardous emissions.
  • Although eye-catching fonts are great from a visual perspective, their file size can seriously weigh your website down. Try to limit the number of different fonts you use, and rely on system fonts like Arial where possible. Likewise, go for web font file formats with better compression methods like WOFF and WOFF2 as opposed to TTF, OFT and SVG file formats.

  • Website code that’s on the messy side can contribute to emissions too. Keep your code clean, simple and straightforward so the back end is as streamlined as possible. And if you’re borrowing code as opposed to writing it from scratch, then be sure to fine-tune and adapt it to achieve that desired performance without the negative effects of added emissions.
  • Try getting into the habit of server caching. Any website that uses a CMS to keep things running has to dynamically produce each page whenever it’s loaded. Without server caching, each page view requires server processing, and all that work increases energy consumption as a result. With a tool like Varnish, however, you can build static versions of each page. This means users don’t have to load the content like it’s the first time over and over again. This drastically reduces things like server overhead, energy consumption and load latency – all of which impact the environment as a result of the emissions they produce.

We hope this article has helped to highlight the impact your website might be having on the world around us. And if you’re looking for a new site that’s beautifully built and optimised to each of your needs, see how our Web Design team can help – give us a call on 0161 504 7007 and let’s get started on something together!

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Oliver Urwin