Mass Appraisal for the Masses
Modern, cutting-edge, free and open source mass appraisal toolkit for researchers, analysts, governments, and everybody else.
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Enrich Data
Download spatial variables from public sources and automatically tag parcels with them.
Get street adjacency from OpenStreetMap, building footprints from Overture, statistics from the US Census, topography from USGS, and more.
Automatically calculate distances between parcels and landmarks you care about—CBDs, universities, golf courses, and beyond.

Deploy AVM Algorithms
Build automated valuation models using MRA, GWR, LightGBM, XGBoost, CatBoost, and more—all through one unified interface.
Ensemble multiple model results together for maximum performance.

Automate Reporting
Generate IAAO-compatible ratio studies and other statistical reports in PDF and HTML formats.
Break down reporting by location, property type, price decile, or any other criteria you define.
Identify variables and characteristics that have the greatest impact on price.

Clean Data
Detect anomalous sales that undermine your predictive models.
Exclude invalid sales with legible and defensible rules.

Stay Organized & Auditable
Set up a clean pipeline that loads, transforms, and merges data without relying on one-off spreadsheet operations.
Define a reproducible set of steps once, then re-run the whole workflow end-to-end as often as you like.

Why Open Source?
Fully Transparent
All the code is out in the open. No hidden algorithms or procedures.
Reproducible Builds
Anyone else can re-run your results with just your settings file and inputs.
Free forever
Full-featured professional GIS capabilities with no software licensing costs.
Ready to get started?
Download the latest release and join a growing user community.
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