About VersusIndex
VersusIndex is an independent comparison and data company based in the Netherlands. We maintain a database of technical data for heat pumps, heat pump water heaters, EV chargers, home batteries, air conditioners and solar inverters. For each model you see the specifications side by side, with the source of every value. For each country we also show the rules that apply to the product, such as grants, noise limits and grid connection.
The expertise behind the data
Data and infrastructure. Our team’s background is in data and IT infrastructure. That is why VersusIndex is built as a data platform: data is collected automatically from official registers and datasheets, and every value is stored with its source and checked against fixed rules, as described below.
Where the data comes from
We do not test or measure products ourselves. We collect data from official registers and from manufacturers:
- Official registers: EPREL (the EU database behind the energy label), Heat Pump KEYMARK, the German BAFA list, the Dutch RVO ISDE list, the UK OZEV and ENA lists, and the lists of the Australian Clean Energy Regulator.
- Manufacturers: datasheets and product pages, mainly for EV chargers, home batteries and inverters. There is no European register with technical data for these.
Every value on the site shows which source we used, with a link to that source. What each register does and does not guarantee, and how we check manufacturer data, is explained in our sources and methodology.
How we check the data
- Each specification has a fixed order of sources. A value from an official register is never overwritten by manufacturer data; if they differ, we review the difference by hand.
- We only take a value from a datasheet if the exact quote appears in the document and the value is within plausible limits.
- In the nightly check an AI model (Google Gemini) looks up specifications on the manufacturer’s website. The model decides nothing: a value only counts if the page belongs to the manufacturer and the value appears on it word for word. Shops, forums and other comparison sites never count as a source.
- A product only gets its own page once we have at least 8 comparable specifications.
- Product photos are official manufacturer photos only, with a credit to the source.
How often we update
- Official registers: every week.
- Checks on manufacturer websites: every night, for part of the products.
- Grants and other country rules: the official pages are checked automatically for changes; a change only goes live after a person has reviewed it.
- Prices: daily.
Every product page shows when its data was last updated.
Independence and affiliate links
- The order of lists, comparisons and positions within a category is calculated from the data alone, using visible criteria. There is no editorial or paid ranking.
- Some links are affiliate links. They are labelled as ads: if you buy or request a quote through one, we may earn a commission. It costs you nothing extra and does not change the data we show.
- Where there is no partner, we link to the brand’s website without any payment.
Indicative, not advice
Noise distances, grant amounts and other calculations are indicative. Always have the final calculation done by your installer or by the body that runs the scheme.
Spotted a mistake?
Let us know through the contact page, ideally with a link to the source. You can also reach us there with any other question about VersusIndex.