Zillow research data

Zillow research data is the set of housing-market metrics Zillow Research publishes free: the Zillow Home Value Index (ZHVI, a smoothed measure of typical home value), the Zillow Observed Rent Index (ZORI), days on market, the share of listings with a price cut, for-sale inventory, new listings, and median sale and list prices. Each metric is offered as a no-key bulk CSV; ZHVI spans every geography level (national, state, metro, county, city, ZIP, neighborhood) while other metrics cover a subset (check the research-data page for what each offers). Used in, for example, Amaral, Dohmen, Kohl & Schularick, where Zillow days-on-market and asking-price-discount metrics proxy liquidity across 277 MSAs.

• Cost: free, public.
• API key: none required (bulk CSV download; there is no official query API).
• Coverage: geography from national down to ZIP/neighborhood; most series monthly. ZHVI runs from 2000; the rent index (ZORI) starts later (2015).
• Home: https://www.zillow.com/research/data/

Access

The research-data page is a directory of download links; the files themselves live on a static CDN at files.zillowstatic.com/research/public_csvs/<metric>/. Fetch a specific file directly, no key:

# Metro-level ZHVI, all homes (single-family + condo), middle price tier,
# smoothed and seasonally adjusted, monthly:
curl -sL "https://files.zillowstatic.com/research/public_csvs/zhvi/Metro_zhvi_uc_sfrcondo_tier_0.33_0.67_sm_sa_month.csv" -o zhvi_metro.csv

Each file is wide: identifier columns RegionID, SizeRank, RegionName, RegionType, StateName followed by one column per month (header is the month-end date, e.g. 2024-01-31).

Load in Python

import pandas as pd

url = "https://files.zillowstatic.com/research/public_csvs/zhvi/Metro_zhvi_uc_sfrcondo_tier_0.33_0.67_sm_sa_month.csv"
wide = pd.read_csv(url)

id_cols = ["RegionID", "SizeRank", "RegionName", "RegionType", "StateName"]
long = wide.melt(id_vars=id_cols, var_name="date", value_name="zhvi")
long["date"] = pd.to_datetime(long["date"])  # month-end dates

Gotchas (the ones that bite pipelines)

• ZHVI is a value index, not transaction prices. It is a smoothed, seasonally adjusted measure of the typical home value in a region, not the prices of homes that sold. For realized transactions use the median sale price files; do not treat ZHVI as a sale-price series.
• The filename is the metadata. sfrcondo vs sfr vs condo, the tier_0.33_0.67 (middle third) vs bottom or top tier or bedroom-count cuts, sm (smoothed) vs raw, and sa (seasonally adjusted) vs not are all encoded in the file name. Pick the slice deliberately; a different file with the same column layout answers a different question.
• Data are wide; date columns are month-end. Reshape to long for panel work, and read the header dates as month-end timestamps, not month-start.
• History is restated every release. Zillow revises the entire back-series on each monthly update as methodology and source data change. Two downloads of the “same” series from different months will differ. Snapshot the file and record the access date.
• RegionName is a label, not a geocode. Metro rows read like New York, NY; there is no FIPS or CBSA code in the value file. To merge with Census, FHFA, or CoreLogic you must crosswalk RegionName/RegionID to standard geography codes yourself.
• Composition changes over time. More metros, counties, and ZIPs enter in later years; a region present in 2026 can be missing (NaN) in 2000. Account for entry rather than assuming a balanced panel.
• No official API. Access is bulk CSV only, and the links on the research page can change. Pull from the static CSV host and archive the file.
• ZTRAX is a different product. The Zillow Transaction and Assessment Dataset (ZTRAX), parcel-level deed and assessment microdata, was a separate, application-gated academic dataset (and has been discontinued for new agreements). It is not part of these free research CSVs.

Reference

Field	Value
Index page	https://www.zillow.com/research/data/
CSV host	https://files.zillowstatic.com/research/public_csvs/<metric>/
Format	Wide CSV: id columns + one column per month (month-end header)
Geography	ZHVI: national, state, metro, county, city, ZIP, neighborhood; other metrics a subset
Frequency	Mostly monthly
ZHVI start	2000; ZORI (rent) from 2015
Key required	No

Citation

Cite Zillow, the specific metric and geography, the retrieval URL, and the access date, for example: Zillow Research, “Zillow Home Value Index (ZHVI),” metro-level CSV retrieved from https://www.zillow.com/research/data/, accessed YYYY-MM-DD. Because Zillow restates the full history each release, record the access date and archive the downloaded file so the vintage is reproducible.