Zillow Assessor and Real Estate Database (ZTRAX)

Dataset Details

Data Summary

IMPORTANT NOTE: the ZTRAX program is being cancelled by Zillow (see https://www.zillow.com/research/ztrax/). The data we have will be destroyed on September 30, 2023. There are also restrictions on new research projects initiated between now and then.

The Zillow Transaction and Assessment Dataset (ZTRAX) is the nation’s largest real estate database made freely available to academic, non-profit, and government researchers. Previously inaccessible and/or prohibitively expensive, Zillow is opening this data up and turning the lights on for the purpose of furthering academic work across various disciplines and addressing important policy questions by creating greater transparency into real estate markets.

ZTRAX is updated monthly and is continually growing. Current data includes:

  • Over 400 million detailed public records across 2,750+ U.S. counties
  • More than 20 years of deed transfers, mortgages, foreclosures, auctions, property tax delinquencies and more, for both commercial and residential properties
  • Property characteristics, geographic information and prior valuations for approximately 150 million parcels in 3,100+ counties nationwide

The ZTRAX real estate database DOES NOT contain:

  • Zestimates
  • Rent data (such as rent prices)
  • Listing data (such as time on market)
  • User search data

(This summary is from https://www.zillow.com/research/ztrax/.)

Geographic Extent

United States

Unit of Analysis

Housing transactions and assessments

Topical Tags

  • Housing

Institutional Partners

CSDE and Sociology

Data Citation

Zillow. 2019. “ZTRAX: Zillow Transaction and Assessor Dataset, 2019-Q4.” Zillow Group, Inc. http://www.zillow.com/ztrax/