Why CO₂ matters
on the web.

The Environmental Impact

I built this app to learn more about CO₂ emissons on the web. I do not pretend to always follow best practice, but we all have to start somewhere!

The internet isn't invisible; it runs on coal-and-gas-powered data centers that stay turned on 24/7. As AI expands, more of these centers are spreading across the earth each day. Collectively, even seemingly small actions can make big differences to our climate challenges.

The digital ecosystem is responsible for roughly 2.1% to 4% of global greenhouse gas emissions. That is equivalent to the entire global aviation industry!

Every single megabyte downloaded emits CO₂. Albeit it’s not jet fuel, the outcome is similar: heavy, unoptimized websites with uncompressed images and bloated scripts quietly add to the internet’s growing climate footprint with every page view.

Read more at The Sustainable Web Manifesto

The Business Impact

Sustainability goes hand-in-hand with web performance. A green website is a fast website.

Dropping your page weight doesn't just lower your CO₂ emissions; it slashes loading times.

Retail giants like Amazon and Google have proven that even a 100-millisecond delay in page load speeds can drop user conversion rates by 7% to 10%.

See Google's Core Web Vitals Guide to learn how search engines rank lightweight, eco-friendly websites higher.

The Accessibility Problem

Bloated websites punish users who aren't on high-speed fiber networks.

Across parts of Africa where connectivity is slower and mobile data costly, millions of people still rely on older smartphones and 3G/4G connections. For example, in Sub-Saharan Africa, almost two-thirds of mobile internet users still access the web through 3G devices.

For these users, loading a massive website can mean spending more of their income on data and waiting longer for pages to load. To craft lightweight websites is not just a performance decision — it’s a matter of digital inclusion and accessibility.