How to reduce the environmental impact of a website while optimizing its performance?

80% of consumers are more loyal to brands that make strong commitments to fight against their digital pollution and 53% of online shoppers say they take into account environmental, ethical, and responsible issues when making their purchases.

But what does the digital footprint mean? To what extent does a website pollute and how can its impact be measured? Answers below.

Environmentally sensitive websites

According to the FEVAD, the French ecommerce sector (products and services) grew by 11.8% in one year and reached 32.5 billion euros in the first quarter of 2022. The number of merchant sites has increased by 11% over one year.

These rising results unfortunately have a direct impact on the digital footprint.

The digital sector is currently responsible for 4% of greenhouse gas emissions and this figure is rising.

On the web, several sources are responsible for the carbon footprint of a site.

Its hosting

Each country has its own energy mix. Thus, visitors who consult the same page from a different country will not have the same impact. In France, it is considered that 1 kilowatt-hour consumed represents 101g of CO2 emitted. In the rest of the world, 462g of CO2 are emitted for each kWh consumed.

Furthermore, the environmental commitment of hosting and cloud providers varies greatly. Let's take the example of the lifespan of machines. On average, a server is kept for 3 years by traditional hosting companies, compared to 5 to 6 years by eco-responsible hosting companies.

Design and content of web pages

The weight of pages is increasing on the Web. More and more data is being transmitted. According to HTTP Archive, the weight of pages has increased fourfold on computers and tenfold on mobiles between 2011 and 2021.

Moreover, the more the visitor browses the website, the more it pollutes: With each action on the site, information has to transit between the server and the visitor's screen and consumes energy. The longer a visitor's journey on your website, the more digital pollution is generated.

According to the Greenmetrics calculator, consulting a page from France produces on average between 0.5 and 1g of CO2. Considering the 1.8 billion websites in the world, that's several million tons of CO2 emitted every month.

And losing momentum

Every visitor is looking for speed. 47% of visitors to an ecommerce site expect a loading time of less than two seconds. If this is not the case, they leave the site. By improving the loading time of your website, you can see an immediate increase in the conversion rate and therefore in your online turnover!

The better a website performs, the less time it takes for visitors to make purchases or access the information they need. A high-performance site is a site that pollutes less with each visit.

By speeding up page loading and improving the user experience, companies reduce the digital pollution generated by their website.

Eco-design for performance

A tool: Greenmetrics Analytics

Greenmetrics has developed the Greenmetrics Analytics tool to assist companies in managing a responsible digital strategy for their website.

In concrete terms, the SaaS platform allows to:

• Automatically and simply measure the performance and environmental and social impacts of a website.
• Manage a sustainable strategy via recommendations integrated into the dashboard.
• Reduce the environmental impact of the site and boost its web performance.

The measurement and analysis allow us to obtain a score. This score is a mark between A and E and is awarded according to the environmental impact. The intuitive dashboard presents this score as well as all the indicators and recommendations to optimize the poorly designed or non-performing elements of the website. The score evolves as actions are taken.

How to reduce the carbon footprint of your website?

The digital pollution of a website is generated by several factors. However, reducing page weight is a key recommendation for lightening a site and improving its performance. Taking into account all resources - HTML, CSS, JavaScript, and third-party resources - the median page weight on mobile is 1440 KB. Images represent 877 KB. On desktop, the observation is similar: out of 1555 KB, 972 KB are images. Therefore, they represent more than 60% of page resources on the web.

Optimizing media (images and videos) therefore has a direct impact on both the web performance of a site and its environmental footprint. In other words, by optimizing the weight of pages and speeding up loading times, we reduce the carbon consumption linked to each navigation.

What results can be observed when a site is eco-designed?

Optimized web performance and controlled environmental impact:

• Better search engine rankings — better SEO
• Better experience for its visitors
• Reduced bounce rateImproved conversions
• Reduction of your website's carbon footprint

Greenmetrics Analytics clients who have optimised their website's video and image content have seen an average reduction of:

• 50% less data on average per web page
• 40% average impact per page (in terms of avoided emissions)
• 0.1 to 0.5 seconds of loading time per page