For a few years, BrainWeb called its hosting carbon neutral. We meant it, and we based it on what our suppliers told us. We've stopped saying it because we can't prove it, and we'd rather explain why than quietly take the label down.

For the same reasons, we don't call our hosting green, eco-friendly, or sustainable either.

Why we can't say it

Carbon neutral means a website's overall effect on the climate adds up to zero. To say that honestly, you'd need to know how much carbon the website is responsible for, and be sure all of it has been cancelled out. We can't do either.

Nobody can tell us what one website produces. Our suppliers report emissions for their whole company, not for each customer. Any figure we gave you for your website would be a guess built on averages.

"100% renewable" usually means paperwork, not power. Most companies that say this buy certificates to match the electricity they use over a year. Their servers still run on whatever the local grid supplies, including gas power at night. And if the wind farm selling the certificates would have run anyway, buying them adds no new clean power. Research published in Nature Climate Change found that this kind of accounting overstates real cuts in emissions.

Planting trees doesn't cancel emissions. Offset schemes pay for trees, forests, or cleaner cooking stoves somewhere else. Forests can burn or be cut down, and some schemes have been found to claim far more than they deliver. One forest project funded by one of our suppliers has been suspended by the organisation that registers it.

Hosting is the smaller part. Most of the energy a website uses is spent on visitors' phones and laptops, and on the networks in between. Our own use of AI tools may be bigger still, and the company behind the AI we use publishes no energy figures at all. A "green hosting" label would describe the smallest part and leave out the rest.

The law has changed. Since April 2025, the Competition and Markets Authority can fine a business up to 10% of its global turnover for misleading green claims, without going to court. If we told you your website was carbon neutral and you repeated it to your customers, we could both be in trouble. Not making the claim protects you as well as us.

What our suppliers do well

None of this means our suppliers are bad. Data centres use extra energy on top of what the servers use, mostly for cooling. This is measured as power usage effectiveness (PUE): a PUE of 1.09 means 9% extra. Google puts the industry average at about 54% extra.

Kualo runs our WordPress hosting in East London. It reports a PUE of 1.09, partly by cooling with outside air. That is Kualo's own figure, and nobody has checked it independently.

Google runs our Payload CMS sites and other Google Cloud services in London and at Eemshaven in the Netherlands. Eemshaven reported a PUE of 1.07 in 2025, and Google says 82% of the electricity it used in the Netherlands was matched with carbon-free power hour by hour, not just over the year. Ernst & Young checked these figures.

Cloudflare, which looks after our clients' domains and protects their websites, has replaced older servers with newer ones that do much more work for the same power.

But Google's total emissions grew 18% in 2025, as AI pushed up its electricity use. A green label would suggest things are heading the right way, and the figures don't show that.

What we do instead

We focus on what we control, which is mostly how much work a website makes servers, networks, and phones do.

Lighter websites. Where it suits the project, we build websites as plain files served from a cache, with no server running all the time.

Servers only where needed. Some websites, such as those that use Payload CMS, need a server running so you can edit them. We decide that project by project.

Smaller images. We resize images and save them in modern formats, so they're quicker to download.

Fewer scripts. We keep third-party code to a minimum. Our usual analytics loads one small script and uses no cookies.

Caching. Pages are saved and reused, so they don't have to be rebuilt for every visitor.

Blocking bad traffic early. Attacks and abusive bots are stopped before they reach your website's server.

Choosing on evidence. When we choose a supplier, we look at what it publishes and whether anyone independent has checked it.

A lighter page uses less energy in the data centre, on the network, and on your visitors' phones. We haven't measured how much we save yet, so we won't put a number on it.

What we don't know

We don't know the carbon footprint of any single website we host, because no supplier provides the data. We don't know the footprint of our own AI use, because the company behind it doesn't publish one. When that changes, we'll update this post.

Read the full report

Our full report covers each supplier in detail, with sources for every figure.

Download "BrainWeb hosting and the environment" (PDF, 13 pages)

To see where your website would be hosted and what's included, visit our managed website hosting page.