Your SCI score, measured from the outside and signed

ISO/IEC 21031:2024 is the first international standard for measuring the carbon intensity of software. It was created by the Green Software Foundation — a Linux Foundation project whose members include Microsoft, Google, IBM and Accenture — and it defines the formula:

SCI = ((E × I) + M) / R

Where E is operational energy, I is the carbon intensity of the electricity grid, M is embodied hardware emissions, and R is the functional unit — here, one page load. Per-segment coefficients come from the Sustainable Web Design Model v4.

And here is what the standard does not cover: it defines how to calculate the number, not how to prove the number is real. Anyone can compute an SCI score and disclose it incorrectly. This measurement is cryptographically signed, with the public key included, so anyone can verify it without trusting us.

• We measure the main document fetch. A page that later pulls video, fonts or ad tags via JavaScript consumes more than what is reported here.
• We apply the global average grid intensity (458 gCO2e/kWh, Ember Global Electricity Review 2026). Your actual region may be cleaner or dirtier.
• We query the Green Web Foundation for renewable hosting status. If it does not respond, we assume it is not renewable — never a factor that flatters the measured party.
• We do not know how much traffic you get — only you do. That is why the figure is given per load and per 1,000 loads, and the final multiplication is yours.

What is exact, and what is signed, are the bytes that actually crossed the wire, the moment of measurement, and the formula applied.

AI spend, measured the same way: from the outside. We read what an AI provider actually consumed without intercepting the API, without an agent, and without spending a single one of that provider's credits. Live, signed, updated twice a day.

Open the live AI meter →

This is the point: the method does not depend on what is inside the thing being measured. Observe from outside, seal the observation. Web pages, AI inference, devices, an entire organisation — same receipt, same signature, same verifiability.

• Your website — right here, right now.
• Your phone — signs its own footprint from the device secure element.
• Your AI spend — without touching your API or consuming your credits.
• Messages, email and traffic — everything that moves has a cost and a footprint.
• A site's electricity draw — from the meter, without entering the equipment.

We issue you a key and your AI systems are measured automatically, with a signed SCI certificate — the kind of evidence already required by California SB-253 (first report due November 2026), EU AI Act Article 53 and the CSRD. See the laws and their official sources →

Write to [email protected], subject API access.