World’s ‘dirtiest’ websites: biggest carbon footprint revealed

Energy & Efficiency

A new report by energy comparison site Uswitch has analysed the carbon footprint of the world’s most popular websites to highlight the environmental impact of our digital lives.

From sending emails and streaming content, to internet shopping and posting content on social media, everything we do online uses electricity. In turn, this produces carbon which negatively affects the environment and can lead to climate change. So, to shed some light on the lesser-known impact of using the internet, the study looked at which of the world’s most popular websites are the cleanest and dirtiest when it comes to carbon emissions.

The Good, The Bad, And The Dirty

Taking the top spot as the ‘dirtiest’ website is the self-titled ‘front page of the internet’, Reddit. The website is used by millions of people around the world as a place to share news, content and discussions. According to the data, a single visit to the website leads to 13.05g of CO2 emissions.  

Another highly used social network comes in as the second dirtiest website. The image sharing site Pinterest emits an estimated 12.43g of carbon from every visit to the site. The gaming website Nintendo, where you can purchase games and consoles, is the third most ‘dirty’ website – every time someone visits the site, it produces an estimated 11.43g of CO2. 

In contrast, the cleanest website is one of the most visited online resources in the world, Wikipedia. The website only produces an estimated 0.04g of carbon per visitor. LinkedIn, the professional social network, comes in second place – emitting just 0.23g of CO2 for every visit, and international fashion brand H&M follows closely behind in third, with 0.29g of carbon being emitted with each visit to their site.  

How Each Website’s Carbon Footprint Was Calculated

To estimate each site’s impact on the planet, Uswitch used a carbon calculator called Website Carbon to compare the carbon emissions of more than 200 of the world’s most popular websites.

The sustainability tool works out the amount of energy that’s used when someone loads a page on a website – this factors in the energy that’s required at the data centre (the cloud), by the telecoms network and by the user’s computer or mobile, as well as factors such a whether the data centre is using green energy to power it.

While more and more of us are making changes to minimise our impact on the planet and to live more sustainably, even some of the most environmentally conscious people might not be aware that our personal carbon footprint is also impacted by our virtual lives too.

You can see the original research here:

Top 25 Dirtiest Websites:

  Website Website type Amount of carbon per website visit
1 Social media 13.05
2 Social media 12.43
3 Gaming 11.43
4 Weather 9.71
5 Sports 6.8
6 Fashion 6.64
7 Fashion 5.22
8 News 4.64
9 Auction site 4.53
10 Ecommerce 4.43
11 Video calling 4.28
12 Homeware 3.52
13 Homeware 3.21
14 Streaming 3.16
15 Weather 3.13
16 News 3.07
17 News 2.95
18 Fashion 2.88
19 Gaming 2.72
20 Technology 2.64
21 Ecommerce 2.54
22 Technology 2.26
23 Stock imagery 1.92
24 Fashion & home 1.89
25 Video streaming 1.85


Top 25 Cleanest Websites:

  Website Website type Amount of carbon per website visit
1 Resource 0.04
2 Social media 0.23
3 Fashion & home 0.29
4 Social media 0.29
5 Financial service 0.34
6 Ancestry database 0.40
7 Website platform 0.43
8 Financial service 0.44
9 Fashion & home 0.45
10 Financial service 0.49
11 Ecommerce 0.49
12 Website platform 0.54
13 Recruitment 0.58
14 Music streaming 0.58
15 Listings website 0.61
16 Social media 0.61
17 Technology 0.65
18 Food delivery 0.66
19 Fashion & home 0.67
20 Supermarket 0.68
21 Courier 0.70
22 Fan fiction 0.73
23 Technology 0.75
24 Technology 0.77
25 Technology 0.83



Chris Price
For latest tech stories go to