Download the extension (.zip)

This extension is not affiliated with, endorsed by, or connected to Zillow Group, Inc. or Move, Inc. (realtor.com). Read the full disclaimer

What it does

  • Reads the price, beds, baths, square footage, and address directly off the Zillow or Realtor.com listing page you're viewing.
  • Saves multiple listings so you can come back to them later without re-entering any numbers.
  • Sends 2–3 saved listings straight into the Mortgage Compare calculator so you can weigh them side by side.

How it works

  • Open a for-sale listing on Zillow or Realtor.com in Chrome, Edge, or Firefox.
  • Click the Domuncula extension icon — it reads the price, beds, baths, sqft, and address straight off the page.
  • Open the data pre-filled into any of the 5 calculators, or save the listing to compare it against others later.

Install it (not yet on the Chrome Web Store or Firefox Add-ons)

Chrome / Edge

  1. Download the zip file using the button above.
  2. Unzip it — you'll get a folder named domuncula-calculator-extension.
  3. In Chrome or Edge, go to chrome://extensions.
  4. Turn on Developer Mode (toggle in the top-right corner).
  5. Click "Load unpacked" and select the unzipped domuncula-calculator-extension folder.

Firefox

  1. Download the zip file using the button above.
  2. Unzip it — you'll get a folder named domuncula-calculator-extension.
  3. In Firefox, go to about:debugging#/runtime/this-firefox.
  4. Click "Load Temporary Add-on."
  5. Select any file inside the unzipped domuncula-calculator-extension folder (e.g. manifest.json) — Firefox loads the whole folder it's in.

Firefox removes temporarily-loaded extensions when the browser restarts, so you'll need to repeat these steps each session. This works in regular release Firefox — no Developer Edition or Nightly required.