The internet is a bigger energy user than most people realise. By some estimates it now consumes over 1,000 terawatt-hours of electricity a year, more than the entire United Kingdom, and produces carbon emissions on a scale comparable to the global aviation industry. The average web page accounts for roughly 0.36 grams of CO2 for every visit. That sounds tiny until you multiply it by traffic: a site with 10,000 monthly visitors is responsible for around 43kg of CO2 a year just from people loading pages.

Websites have a carbon footprint, and in 2026 more businesses are starting to ask what theirs looks like.

Why it matters more now

Sustainability has moved from a nice-to-have to something clients, partners, and procurement teams actively ask about. A slow, bloated website isn’t just an environmental cost, it’s usually a slower, more expensive, less accessible one too. Building lighter, cleaner websites tends to pay off on all of those fronts at once, not just the carbon count.

What actually makes a website low-carbon in 2026

It starts with lean code. Every unnecessary plugin, script, and font file is data that has to be transferred and processed, so the biggest wins usually come from stripping out what a page doesn’t need rather than adding anything new.

Image format matters more than most people think. WebP was the standard a few years ago; AVIF now compresses further again without a visible quality loss, and choosing the right format for a page’s images can cut its weight dramatically.

Hosting is worth checking, not assuming. The Green Web Foundation maintains a public directory of verified green hosting providers, and it’s a two-minute job to check whether a host actually runs on renewable energy rather than just claiming to.

A content delivery network and sensible caching reduce how far, and how often, data has to travel to reach a visitor. Fewer round trips to a distant server means less energy spent moving the same content over and over.

Performance and carbon efficiency are, in practice, the same problem looked at from two angles. A site that loads fast is almost always a site that’s transferring less data and asking less of the visitor’s device, so the same discipline that improves Core Web Vitals tends to lower a site’s carbon footprint too.

And it’s worth measuring rather than guessing. Tools like the Website Carbon Calculator and the Green Web Foundation’s CO2.js library give you an actual number for a page, so you can see whether changes are working rather than assuming they are.

How we approach this at Class

We build everything in-house, which means we control the stack rather than stacking plugins on top of a template. We compress and serve images in modern formats by default, keep our own hosting on renewable energy, and treat page weight as something to justify, not something to ignore. It’s not a separate initiative bolted onto our process, it’s part of how we build sites day to day.

Conclusion

Low-carbon web design isn’t a trend that’s going to pass. It’s a natural extension of building fast, well-made websites, and in 2026 it’s increasingly something clients expect rather than something they have to ask for. If you want to know what your own site’s footprint looks like, or want a rebuild that takes this seriously from the start, get in touch and we’ll talk you through it.