Nestfair

Privacy policy

Last updated 18 August 2026. Nestfair is a product of Arvorithm Labs Ltd (registered in England & Wales, company no. 17376192).

What the browser extension does

When you open a property listing on Rightmove, Zoopla or OnTheMarket and click Value it, the extension reads the property’s public details from that page (address, asking price, floor area, bedrooms and bathrooms) and sends the address to nestfair.co.uk to produce a valuation. It only runs on those listing pages, and only does anything when you click. It does not read any other pages or run in the background.

What we store

• A cached copy of each report (the property address and the resulting valuation), so repeat lookups are fast and cheap. Cached reports are addressed by an unguessable key and are not publicly listed.
• A record of the property listings valued through Nestfair: the public listing details (address, asking price, floor area, bedrooms and bathrooms) and the estimate we produced. We keep this to improve our valuation models and to understand how asking prices move over time. It is information about the property, which is already publicly advertised on the listing, not information about you: we do not store your IP address, your name, or anything that links a lookup back to you.
• A lightweight usage log holding only the outcode (for example “N1”), whether the request came from the website or the extension, and a timestamp. We do not log your IP address, your name, or anything that links you to a specific property.
• To surface your own address first when you search, we estimate your approximate location (town/region level) from your IP address and use it only to order the search suggestions. Your IP is sent to a geolocation provider for this and held briefly in memory so we don’t look it up repeatedly; it is not written to our logs and not stored with any report.

What we do not do

We do not sell your data. We use no advertising and no cross-site tracking. The third parties we contact are the services needed to build a valuation and run the address search: HM Land Registry and the EPC register (property data), postcodes.io (turning postcodes into map coordinates), map tile providers, and an IP-geolocation provider (for the location ordering described above). Only the property address or postcode is sent to the data sources; only your IP address is sent to the geolocation provider, and only to estimate your approximate area.

Your rights

Under UK GDPR you can ask what we hold about you and request its deletion. Because we store outcode-level usage only, there is normally nothing that identifies you personally. To make a request, email [email protected].

Changes

We may update this policy; the date above shows the latest version.