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What contributes to a website’s carbon emissions?

A website is composed of a great many components, and they all create some form of carbon emission by virtue of the fact that they all have to be stored in a data centre, which guzzles up a fair amount of power.

Here are the main culprits.

The five factors that drive website carbon emissions

To list out every single thing on a website that contributes to carbon emissions would result in a very big page. So it’s simpler to think of it in terms of them falling into five groups. The Five Factors of Website Carbon if you will.


When your device access a website data has to be transferred so that you can view it. From a plain old HTML page that is nothing but text to an all-singing, all-dancing immersive digital experience with video, sound, fancy animations and transitions and sweet carousels, there is some data exchange going on. And as you can imagine that takes power, which causes carbon emissions. As a general rule, energy consumption tracks along with the amount of data transferred, and how the site is built also has an impact here. Big files, plus fancy animations, plus bad coding all adds up to big data which leads to big energy burn, which leads to…more carbon

2.Energy intensity

The actual energy intensity of web data has three contributing factors: the data centre, the telecoms network, and the end user’s device. On average a gigabyte of data transferred uses 1.8 kilowatt hours of electricity.

3.The data centre

The energy source used by the data centre hosting the website is also a major factor. Some data centres are run on green, renewable energy sources, some offset their carbon emissions, and others are just run on plain grid electricity.

4.The carbon intensity of electricity

Carbon intensity is the amount of carbon produced to make one unit of electricity (the aforementioned kilowatt hour). This varies based on the energy source: electricity produced by coal or gas is much more carbon intense than that produced by hydro or solar power.

5.Website traffic

The more traffic accessing your website, the more data is going to be transferred around the place. This also varies based on new or return traffic! More visits will mean more carbon emissions.

We can help you clean up your site

The things we’ve learnt on our own journey to a cleaner site has given us greater insight into how to make sites clean but also beautiful and able to deliver on marketing and brand objectives. We’d love to help you improve your site.

Get in touch

Why should you care?

The carbon impact of your website is important for the environment. And our research also shows it is becoming more important to customers. Find out more.

Discover why you should care

Cleaning our act up

We recognise that we’re also part of the problem (and our website isn’t a paragon of greenness). Find out what we’re doing to be part of the solution.

Here’s how we’re helping