Most Popular Website Carbon Emissions



Keyboard with ‘zero emissions’ written on the enter key

Even the most environmentally conscious people may not know that a person’s carbon footprint, the amount of carbon released into the atmosphere as a result of your daily life, is also affected by their virtual life.

Everything from shopping on the internet to sending emails to streaming content produces carbon emissions that negatively affect the environment and can lead to climate change.

But not all online carbon footprints are created equal – in fact, there is a marked difference in emissions between some of the most popular websites in the world. To find out more, we used the Website Carbon Calculator to find out which site home page uses the most power to load, including factors such as whether the data center is using green power or not.

So which sites are the “dirtiest” in terms of carbon impact, and which are the most environmentally friendly? Read on to find out more…

Looking at the UK’s 200 most popular websites, the dirtiest for the environment is the eponymous “Internet front page”, Reddit. The website is used by millions of people around the world to share news, content and discussions. According to the data, a single visit to the website results in 13.05g of CO2 emissions. It is estimated that there are around 430 million active Reddit users per month worldwide, so a single visit to the homepage for all of these people would equate to more than 5,611.5 tonnes of carbon emitted each month. . That’s the same amount of energy it takes to power about 2,374 homes for an entire year.

The UK’s second dirtiest website is the ideas and inspiration platform, Pinterest, which emits around 12.43g of carbon with every visit to the homepage. With approximately 415 million monthly active users, a single visit to each of them’s home page would equate to approximately 5,157.5 tonnes of monthly carbon emissions.

The UK’s cleanest websites

Taking the # 1 spot as the cleanest website is one of the world’s most visited online resources, Wikipedia. The website produces approximately 0.04g of carbon per visitor. It appears that the site’s simplistic design is having a positive impact on its environmental footprint, which is hugely beneficial considering the site receives around 5.83 billion visits per year.

LinkedIn, the professional social network, comes in second – emitting 0.23g of CO2 for each visit, closely followed by international fashion brand H&M, with 0.29g of carbon emitted on each visit to its site.

Sites with the highest carbon emissions

Popular sites in the United States present a very similar picture to that of the United Kingdom, with Reddit, Pinterest and Nintendo topping the list of worst carbon emissions per click on the homepage. The American list does include some brands specific to the United States, however, including the Banggood electronics store and household goods suppliers such as Kohls and Home Depot.

The cleanest websites in the United States

When it comes to cleaner sites, this is also a very similar point of view to the UK listing, although the US naturally lacks some local UK brands like Marks and Spencer. Instead, some of the lower emitting sites in the US include Dominos, FlipKart, and the Japanese Fc2 website platform.

Website carbon emissions by industry

You might find that you typically visit certain types of sites more than others – maybe you’re a social media lover or check out clothing sites regularly to keep an eye out for the latest trends. Many of us have also spent a lot more time on certain sites to make working from home easier. To dig a little deeper into the carbon emissions of different websites, we’ve broken down the data by sector. Read on to find the best and worst offenders …

Social media

Many of us log into our social media profiles every day, and there has been a lot of talk about the effects these platforms can have on our mental well-being. However, you may not have taken into account the environmental impact that just connecting to your preferred network could have.

One of the world’s most popular instant messaging apps, Viber, has over 1 billion members, including over 260 million monthly active users. However, it tops our list of social media sites with the highest carbon output, producing over 13g of carbon per view.

On the other end of the scale, video creation and social networking service Triller has an insanely low level of carbon emissions of just 0.02g per view (the lowest of any website presented in our research). While it may be beaten in popularity by its similar rival TikTok, it turns out to be a much more eco-friendly option.

Work at home

An abundance of previously unknown or underused sites have grown in popularity over the past year, with their usage increasing thanks to a dramatic increase in remote working. Overall, work-from-home websites have performed quite well compared to other industries, with even the top-emitting sites still showing only moderate numbers.

While we weren’t able to keep track of the numbers for every work-from-home site, among those on our list, it was clear that the DropBox file-sharing platform produces the most amount of carbon, with 7.35 g emitted per visit.

Meanwhile, the project management and internal communication tool Basecamp showed the lowest emissions with 0.23 g of carbon emitted per visit.


While still popular, entertainment and streaming sites, which are regularly used for watching TV, chilling out with a movie, reading reviews, or gaming, have also seen an increase in their usage over the past year. because we all spent more time looking for recreational fun in our homes.

Japanese games company Nintendo releases the highest amount of carbon in this category, with a carbon emission of 11.43g per visit to its website, far higher than the rest of the list. Amazon’s movie and series streaming service Prime Video can be proud to hold the title for the lowest carbon emissions per visit in the entertainment industry, producing just 0.38g for every click.


Whether it’s grocery shopping or take out, home food delivery has been a lifeline in helping many people enjoy their favorite meals over the past year. But what cost could these sites have from a carbon point of view?

Diet company Slimming World, whose site contains recipes and tips, produces the highest amount of carbon on our food industry list, emitting 3.26g per homepage visit. On the other end of the scale, multi-restaurant delivery service Deliveroo can claim to be the most eco-friendly website on our list, producing a minimum of 0.45g per click.

Fashion / Shopping

Renowned for its beautiful underwear and impressive live fashion shows, Victoria’s Secret is one of the most iconic lingerie brands in the world. It is also one of the highest carbon emitting sites in the fashion category, producing 6.64g of carbon per click on the home page.

On the other end of the scale, budget clothing retailer H&M may be known as a fast fashion outlet, but its website is the lowest in the industry in terms of carbon emissions, with only 0.29 g per visit.

To travel

Travel is rarely an industry lauded for being carbon-friendly, with long-haul flights generating more carbon emissions than the average person produces in a year. However, when it comes to their websites, they are relatively low on the emissions scale compared to other industries.

The biggest producer of carbon is Qatar Airways, but with its figure of 3.16g per homepage click being the highest number on the list, that’s still pretty impressive considering that many other sites register well over four times that amount.

Meanwhile, the Rome2Rio travel and vacation aggregator is the cleanest site in the travel category, with 0.32g of carbon emitted per homepage visit.


Another industry historically associated with high emissions (although modern technologies certainly show huge environmental improvements), our automotive category has produced some interesting results. We expected electric vehicle and clean energy company Tesla to top the list of cleanest sites, but it was actually the 7th worst in the industry, with 2.79g of carbon produced. by clicking on the home page. This figure was, however, significantly lower than that of Mazda, which was by far the biggest emitter of carbon at 16.19g per visit.

On the other end of the scale, Japanese automaker Honda was able to take the # 1 spot for the cleanest website in its class, with 0.71g of carbon produced per homepage visit.


And finally, another type of business historically known for its questionable environmental impact is the cosmetics industry, although many brands have tried in recent years to move towards greener ingredients and production methods.

The American makeup and skin care brand Clinique’s website produces 9.63g of carbon per homepage visit, making it the largest emitter in the category. Meanwhile, affordable skin care brand The Ordinary is the cleanest in the business, producing 0.67g per click.

With this new knowledge of the dirtiest and cleanest sites on the web, do you think you are going to change your behavior online? One step might be to find a broadband Where energy supplier who has ecological interests at heart. Compare green energy offers to know more.

Want to understand the impact of your own carbon footprint? Head to our carbon footprint calculator.


All carbon estimates are based on data from Carbon Website and are correct as of February 2021. Site carbon emissions may change due to website changes.

The best websites in UK and US were based on SimilarWeb’s 200 best websites. Pornographic sites have been removed. Industry-specific lists have also been compiled using SimilarWeb’s UK top-down list of top-visited sites by industry.

Not all sites could be scanned using the Website Carbon calculator.



Comments are closed.