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Driving digital sustainability: The impact of small changes on the web

Profile photo of Davs Howard.

By Davs Howard

5 min read

A stack of dominoes knocking each other over, smallest to largest.

Back in 2015 when Google revealed their new Logo, I remember they stated how it had reduced the file size due to the simplification of the typeface. Whilst unable to find the source now, I recollect reading about approximately, how much that may have saved Google in hosting costs.

Using an approximation of file size, we can assume a saving of 9kb for the logo, which, given the approximate 8.5 billion searches being made on Google every day, that's a huge amount of bandwidth saved (~58TB daily accounting for a degree of caching) which equated to around $10k a day in data transfer costs at the time.

My mind was blown by these numbers 8 years ago, such a huge financial saving from such a minor change. That's the effects of massive scale.

A different kind of green

Now, consider the environmental impact from that same change, the electricity that isn't required for 21 Petabytes of annual bandwidth. All from a single alteration on a single, albeit widely used, website.

Calculating digital emissions is hard. Really hard. Figures for the amount of energy used for data transferred varies wildly (the reasons why a-whole-nother topic), and the magnitudes of variance can be massive.

Take the 21PB for the Google logo example - with that figure itself being an estimate - that could be ~7,600 tonnes assuming a standard ratio of new visitors to returning visitors (75% to 25%) on standard (global grid) hosting, shift that to 50/50 new/returning visitors and it's ~5000 tones and then move that to renewable hosting and that number drops to ~575 tonnes.

For reference, a one tonne of CO^2^ is equivalent to 3,600 miles driven in an average petrol car (based on UK average car emissions of 2.2kg per mile and 36 miles per gallon).

These numbers are big, but are just an example of the impact small changes can make. Whilst not all of us have the access or ability to make a significant impact like this, we do have the ability to make simple macro changes that, when amplified, make a large dent in the carbon emissions of the web.

Scale can also be achieved by volume of people and sites, rather than views of a single site or service.

Therefore, here are some of the easier yet impactful changes you can make to your website that, collectively, will help drive positive digital sustainability:

Optimise your images

This is probably the easiest action you can undertake. Whether it's using good image compression tools (if you're website platform doesn't have anything built in you can use services like, resizing and outputting images to be the correct size (we've seen too many HD images in a 100px square space in our time).

Large, high-resolution images can slow down page loading times and increase data usage. Compressing images and using appropriate image file formats can help improve website performance.

Do you need that third-party script?

Third-party scripts, such as tracking codes, social media widgets, or even embedded videos, can slow down page loading times and increase data usage. Minimising the use of these scripts can help improve website performance.

Ask yourself, do you really need that analytics tracking code? Or can you use a lighter one (e.g. Plausible Analytics over Google Analytics). Do you use that data or does it just sit there to occasionally peek at how many visitors you get?

Fewer files, smaller files, closer files

Storing files on a hard drive somewhere (on a server or in the cloud) requires electricity, sending files across the internet requires electricity, therefore, fewer files and smaller files require less electricity.

That includes your HTML, CSS, JavaScript, PDFs, videos, and of course, images. Smush them down, make them as compact as possible (without necessarily losing any noticeable quality), only store and send the ones you actually need, and then send from a location near your user.

Using a content delivery network (CDN) is a good way to help reduce the load on a website's server by distributing content to users from servers located closer to them. But that's negated if you're sending loads of huge files.

Caching here, there and everywhere

Browser caching allows a website's resources to be stored locally on a user's device, reducing the need to re-download them each time a user visits the website. This means that when you revisit a site you've already visited recently, certain assets (like images, stylesheets and JavaScript files) don't have to be retransmitted to you.

This massively helps with website speed and energy usage; returning visitors are assumed to be 25% but use just 2% of the data transmitted as a new user.

Renewable hosting

The carbon factor between standard and renewable powered hosting is more than eight-fold. A switch to a hosting environment that is powered by renewable energy is one of the best ways you can reduce the carbon impact of your website.

For an extensive list of green hosting providers, review the Green Web Foundation's Green Hosting Database.

Be a megaphone

Many of the sites that we work on may reach tens of thousands or even hundreds or millions of users a year, it could be multi-millions of page views. Making a 100KB saving may not really matter on an individual level, but when viewed millions of times, and the same is achieved over dozens, hundreds, thousands of websites it will start to make an impact.

Therefore it's important to learn and educate others, pass knowledge onto site administrators, friends, colleagues, peers, clients, partners, anyone that has a website they run or manage as a touchpoint in their jobs or lives. Be a megaphone for digital sustainability.

If you don't know where to start, then we recommend getting a free emissions audit for your website from the Eco-Friendly Web Alliance.

Need help achieving the target of under 1g of carbon per page?

We can assist with educating, identifying or solving your digital sustainability needs.

  • Climate-Positive Website - EFWA Accredited.
  • Ecologi.
  • SME Climate Hub.
  • The Green Web Foundation.