How much CO2 does your website burn?
The internet produces more carbon than most countries. Test any page in seconds and see its grade, its footprint, and what it would take to offset it. Built on the Sustainable Web Design model.
What that footprint equals in a year
We measure the page HTML plus its linked assets (0 counted on this test), check green hosting with The Green Web Foundation, and apply the Sustainable Web Design model (0.81 kWh/GB; 442 g CO2/kWh grid, 50.9 g/kWh renewable). Results are per page and vary with caching and devices. Equivalents are rough: 8.22 g per phone charge, 192 g per km in an average gas car, 21 kg absorbed per tree per year. Planet Media donates a percentage of every project to One Tree Planted.
Why it matters
The internet runs on electricity. Most of it still comes from fossil fuels.
Every page view spends real watts in a data center, a network, and a device. Multiply by billions of views and the web becomes one of the largest machines on the planet.
of global carbon emissions come from the internet, roughly the same as the airline industry
the median web page weighs today, about three times heavier than a decade ago
of CO2 emitted by a typical page view. Good pages stay under 0.2 g
How it works
No magic. Just measurement.
We weigh the page
Your HTML plus the images, scripts, and stylesheets it actually loads. Real transfer, not guesses.
We check the power
The Green Web Foundation database tells us whether the host runs on verified renewable energy.
We do the math
The Sustainable Web Design model converts data into energy into CO2, and CO2 into your grade, from A+ to F.
Model constants: 0.81 kWh per GB transferred; 442 g CO2 per kWh on the standard grid, 50.9 g on renewables. Results are estimates per page view.
Quick wins
How to burn less
Put your images on a diet
WebP format, right-sized, compressed. Media is usually 60 to 80 percent of a page's weight.
Fire the scripts you do not use
Every tracker, widget, and forgotten plugin bills the planet on every single visit.
Switch to green hosting
Same website, renewable grid. Under the SWD model that single move can cut emissions by up to 9x.
Load later, cache harder
Lazy-load below the fold, cache aggressively, and keep your fonts to one family.
The badge
Proud of your grade? Wear it.
Add this badge to your footer to show visitors your site runs clean. It links back here so they can test theirs too.
FAQs
Questions, answered
What is a good website carbon score?
Under the Sustainable Web Design model, anything below 0.185 g of CO2 per view rates an A, and below 0.095 g an A+. The typical page emits around 0.8 g, so landing under 0.2 g puts you ahead of most of the web.
How accurate is this checker?
It measures the real transfer size of your page and its linked assets, verifies green hosting against The Green Web Foundation database, and applies the industry-standard SWD model. Results are honest estimates per page view: caching, devices, and dynamic content make every visit slightly different, but the grade is directionally solid.
Why did my score change between tests?
We cache each result for 24 hours, so same-day repeats return the same number. Across days, scores move when your page does: new images, added scripts, a CDN warming up, or rotating content all change the transfer weight.
Does a lighter site help my SEO too?
Yes. Page weight drives loading speed, and speed is both a Google ranking factor and a conversion factor. The same work that lowers your carbon grade improves your Core Web Vitals. That is the whole idea behind sustainable web design.
Lighter sites. Happier planet. Better business.
Your carbon grade is one of many things costing you customers. Our free 3-minute brand audit scores your positioning, website, and visibility, then hands you your top 3 fixes. No call, no spam, built for eco-brands.
