Krystal vs Kualo: green hosting compared
Krystal and Kualo side by side: each one's Green Web Foundation listing, where its data centres are and how carbon-intensive those grids are, and the evidence it publishes. They are in alphabetical order: no host pays for its place.
The difference
Both are listed in the Green Web Foundation's directory of verified green providers.
Neither host's listed countries all have lower-carbon grids than the other's. Across both, their countries' grid averages run from 218 gCO2e/kWh in the United Kingdom (2025) to 384 gCO2e/kWh in the United States (2025), so which grid your site runs on depends on the region you choose.
On the listing and the grids, the evidence here does not separate them.
These are the facts we can show, not a verdict on which is greener: the listing, the grids and each company's own claims measure different things, and none of them measures your website. Each host's full page has every quote and source.
Each dot is a country where the host lists data centres, placed by that country's grid average. Krystal, listed in the Green Web Foundation's directory: 3 countries, from 218 gCO2e/kWh in the United Kingdom to 384 in the United States. Kualo, listed in the Green Web Foundation's directory: 2 countries, from 218 gCO2e/kWh in the United Kingdom to 384 in the United States.
Show the data as a table
| Country | Grid average, gCO2e/kWh | Year | Krystal | Kualo |
|---|---|---|---|---|
| United Kingdom | 218 | 2025 | Yes | Yes |
| Netherlands | 254 | 2025 | Yes | No |
| United States | 384 | 2025 | Yes | Yes |
Krystal
- Green Web Foundation
Listed in the Green Web Foundation's directory of verified green providers, checked 17 October 2026.
GWF lists it as “Krystal” (provider 709).
GWF does not publish when a provider was last verified. Providers verified before October 2026 are reassessed under its new criteria, which no longer accept offsets, at their next reverification.
- Data centres
United Kingdom, Netherlands and United States
Krystal's own servers in space it rents from data-centre operators in London, Amsterdam and the USA.
- Grid average where they are
- Across the listed countries, from 218 gCO2e/kWh in the United Kingdom (2025) to 384 gCO2e/kWh in the United States (2025).
- Krystal's own evidence
- Green Undated
- Climate Action Plan 2026–2029 2 July 2026
- Technology Undated
- Evidence checked
- 16 October 2026
Kualo
- Green Web Foundation
Listed in the Green Web Foundation's directory of verified green providers, checked 17 October 2026.
GWF lists it as “Kualo” (provider 661).
GWF does not publish when a provider was last verified. Providers verified before October 2026 are reassessed under its new criteria, which no longer accept offsets, at their next reverification.
- Data centres
United Kingdom and United States
One data centre in East London and one in Tampa, Florida; customers choose.
- Grid average where they are
- Across the listed countries, from 218 gCO2e/kWh in the United Kingdom (2025) to 384 gCO2e/kWh in the United States (2025).
- Kualo's own evidence
- Green web hosting Undated
- Green web hosting Undated
- Kualo commits to 100% renewable energy (Green-e) 16 July 2017
- Evidence checked
- 17 October 2026
Grid figures: Ember, Yearly electricity data (2026), CC BY 4.0. Listing data from the Green Web Foundation's Green Web Dataset, made available under the Open Database License (ODbL).