Free Chrome extension
See the Sienna® Score on every Rightmove listing
Get an instant fair value, recommended offer and Buy / Negotiate / Walk verdict the moment you open any property on Rightmove, Zoopla, or OnTheMarket.
Works in Chrome, Edge, Brave, Arc, and Opera.
Install in 4 quick steps
1
Download & unzip
Click the download button above, then unzip the file anywhere on your computer.
2
Open chrome://extensions
Paste chrome://extensions into your address bar (works in Edge, Brave, Arc, Opera too).
3
Enable Developer mode
Toggle Developer mode on in the top-right of the extensions page.
4
Load unpacked
Click 'Load unpacked' and select the unzipped extension folder. You're live.
One-click verdict
Buy, Negotiate Hard, or Walk Away — right next to the asking price.
Works everywhere
Rightmove, Zoopla, OnTheMarket — same Genie Score, same fair value.
Free & private
No account needed. Only the listing URL is sent to our servers for analysis.