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CO₂ & EmpCo

CO2 verification: the digital footprint of your website

Each page view consumes energy — for transmission, server and the visitor’s device. We measure how much your pages load and estimate the CO2 emissions per call, according to the established Sustainable Web Design Model. In addition, we check whether your hosting runs demonstrably with green electricity. Since 27 September 2026 this includes the EmpCo Directive (EU) 2024/825: we check the environmental claims on your website and hold them against the measured values.

Page weight · transfer · SWDM · green web hosting · image sizes (co2-v2)Scope and rule set are stated in the report, countable.
Human reviewClear decisions in the gold standard: a person judges disputed cases.
TraceableEvery finding with reasoning, source and location.
Publicly verifiableVia audit ID, QR code and an open verification page.

What is checked in detail

Page weight and amount of data actually transmitted per call, measured in the real browser
Number of HTTP requests and their breakdown by images, JavaScript, fonts and third parties
Image optimization: modern formats (WebP/AVIF), dimensioning, compression
Intermediate storage (cache efficiency) — which unnecessarily reloads recurring calls
Estimated CO2 emissions per call, extrapolated to 1,000 and 100,000 calls
Hosting power mix via the Green Web Foundation database (green / not demonstrably green)
Environmental claims under the EmpCo Directive: generic claims, climate neutrality through offsetting, labels, targets and comparisons, held against hosting and data volume

How your measured value comes about

Prove the domainDNS TXT record or file in the .well-known path.
Choose the scopeBy page tier, up to 1,000 pages.
Automated auditEverything technically decidable is measured.
Auditor judgementA person judges disputed cases, in the gold standard.
Measured value in the reportScore out of 100, findings with measures, comparison with the previous run.

Digital footprint and ESG reporting requirements

For more and more organizations, the ecological footprint of their digital offerings is becoming part of sustainability and ESG reporting. A lighter website not only reduces emissions, but also loads faster — especially on mobile networks.

Our audit is a technical estimate based on the transmitted data and publicly available hosting information; it does not replace a certified CO2 balance. It shows resiliently where the heaviest posts are and what can be improved most effectively.

The result: a measured value in the report

CO₂ is measured and reported: page weight, transfer, estimated emission per visit and whether the hosting demonstrably runs on green power. There is no seal for this audit area: from 27 September 2026, sustainability claims require a certification scheme under Directive (EU) 2024/825. How the audit works is described in the audit procedure, the conditions under pricing.

Get your website audited

What a result looks like

Every criterion receives exactly one of three judgements. A criterion is never considered met just because the measurement found nothing.

Met: demonstrably, with evidence
Still open: awaits an auditor judgement
Still to be met: location, rule and remedy named

The measured value is in the report — without a seal for this audit area.

Our own website currently reaches 79 of 100.

Frequent questions about CO₂ & EmpCo

How is the CO2 number calculated?

According to the Sustainable Web Design Model: the amount of data transmitted is used to estimate the energy demand and CO2 emissions per call. If the hosting runs with green electricity, the assigned factor decreases. It is an understandable estimate, not a certified balance sheet.

Where does the information on green energy hosting come from?

From the public database of the Green Web Foundation. If your provider is not listed there as green, we show this as "not proven green" - this may also mean that the proof has not yet been filed.

What does the EmpCo part check?

The environmental claims on your website, sentence by sentence: is there a specific feature next to “sustainable” or “eco-friendly”? Is “climate neutral” based on offsetting emissions? Is a label certified, a target linked to an implementation plan, a comparison backed by a basis? Every finding names sentence, rule and measure. The part has its own score next to the CO₂ value; it is a technical audit, not legal advice.

Do you accompany the change to green energy hosting?

Yes, as an additional service for each tested site: inventory of today’s hosting, move to a server with green electricity, re-measurement in this audit area. The price is called the price page; the booking follows as soon as the first green server is available.

Good to know

The amount of data actually transmitted is measured in the real browser.
The CO2 value is a reasonable estimate, not a certified balance sheet.
Green Energy hosting comes from the Green Web Foundation database.
When certifying, real call numbers can refine the extrapolation.
CO₂ is a measured value in the report, not a seal — sustainability labels require a certification scheme from 27 September 2026 (Directive (EU) 2024/825).