Zillow’s Transaction and Assessment Database (ZTRAX)
The Zillow Transaction and Assessment Dataset (ZTRAX) is the nation’s largest real estate database made freely available to U.S. academic, non-profit and government researchers.
The Zillow Transaction and Assessment Database (ZTRAX) is the nation’s largest housing and real estate dataset, providing researchers with unparalleled access to public records on the U.S. housing market.
ZTRAX is available to the research community through a partnership with the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan. Zillow continues to produce and update the dataset, which is now distributed exclusively by ICPSR.
What data is included in ZTRAX?
ZTRAX is a comprehensive, nationwide dataset built from public records covering both residential and commercial real estate.
These data include:
- 400+ million detailed public records across 2,750+ U.S. counties
- 20+ years of housing market history on commercial and residential properties, including:
- Deed transfers
- Mortgages
- Foreclosures and auctions
- Property tax delinquencies
- Property attributes such as characteristics, geographic information, and historical valuations for approximately 150 million parcels in 3,100+ counties, nationwide
ZTRAX does not contain:
- Zestimates
- Rent data (such as rent prices)
- Listing data (such as time on market)
- User search data
The ZTrax data will be updated approximately twice per year.
Accessing the data
ZTRAX is available to qualified researchers through ICPSR.
- Data access is restricted and requires an application process
- Researchers at ICPSR member institutions can access data at no cost
- Non-members may also apply for access
Apply and learn more: https://www.icpsr.umich.edu/web/ICPSR/studies/39652
Continuing Zillow’s commitment to housing research
Zillow created ZTRAX to expand access to high-quality housing data and support independent research that improves understanding of the housing market.
With ICPSR as its new home, ZTRAX continues that mission—helping researchers, policymakers, and communities make more informed, equitable decisions about housing.
