https://sustainablewebdesign.org/
https://abookapart.com/products/sustainable-web-design
There are tools that estimate the carbon footprint of a website
Website Carbon™ provides an estimate of the carbon emissions associated with a single load of a webpage. When you add a URL to the calculator and click calculate a number of things happen. Firstly it loads the webpage in the same way a human using a browser would. This gives the calculator it’s first data point, the data transfer in KB. This is the amount of data it takes for a page to load. The calculator uses this amount of data transfer and estimates the amount of emissions based on V4 of the Sustainable Web Design Model. The model uses the global average grid intensity to estimate the emissions associated with hosting. It checks the Green Web Foundation Directory to verify if hosting uses renewable energy. With those checks done, Website Carbon™ then adds in an amount of emissions associated with the transmission network. This is based on the amount of electricity required to transmit the data from the host to your device. Finally, the calculator adds the emissions associated with you loading the page. As with hosting, this calculation uses a global average grid intensity. You should note that the type of device is not taken into consideration. Based on the above factors, the webpage will be given an amount of CO2e emissions in grams and an associated rating.
- first page load in KB → emissions associated with hosting, see also Green energy
- amount of electricity to transmit from host to device → emissions associated with data transfer
- page load on user device → emissions associated with page load (type of device excluded)
2025/11/26
This website has a rating of F currently. That’s pretty bad!
https://www.websitecarbon.com/website/opheliagame-github-io-garden/
Over a year, with 10,000 monthly page views, opheliagame.github.io/garden produces 79.94kg of CO2 equivalent. As much CO2 as boiling water for 10,833 cups of tea
162 kWh of energy As much C02 as 13,486 full charges of an average smartphone
86 billion bubbles Woah, that’s a lot of bubbles!
4 trees This web page emits the amount of carbon that 4 trees absorb in a year.
162kWh of energy That’s enough electricity to drive an electric car 1,036km (or 644 miles).