Question 1

How does Carbon Thinking calculate a website’s carbon footprint?

Accepted Answer

It measures the real on-the-wire data transferred when loading a page, then applies the Sustainable Web Design Model (SWDM v4): the data is converted to energy across data-centre, network and user-device segments (operational and embodied), and multiplied by the carbon intensity of the electricity grid to produce grams of CO₂e per visit.

Question 2

Is Carbon Thinking free?

Accepted Answer

Yes. Carbon Thinking is a free product and resource by Keepthinking.

Question 3

Does it measure images and assets loaded by JavaScript?

Accepted Answer

Yes, optionally. Enabling “Measure JavaScript-loaded assets” renders the page in a headless browser so assets a single-page app requests at runtime (such as images loaded after the page boots) are included in the measurement.