Trust
Data Sources
Source-of-truth datasets and references used by zipappreciation.com.
Last updated 2026-06-18
Primary data source
The core pages use public FHFA HPI® data. ZIP3 pages use quarterly all-transactions 3-digit ZIP regional index files. State and national context use FHFA master HPI all-transactions quarterly records.
The source files are imported into a generated dataset during the build process. Each data page displays the latest imported period and import date.
Geography source rules
The site does not infer ZIP5 or address-level values from 3-digit ZIP regional data.
A sourced geography crosswalk may be used for navigation or labels, but it should not be used to claim parcel-level precision.