Mass Appraisal for the Masses

Modern, cutting-edge, free and open source mass appraisal toolkit for researchers, analysts, governments, and everybody else.

Get Started
Analysis toolbox screenshot

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.

Map creation screenshot

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.

Reporting screenshot

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.

Editing layers screenshot

Clean Data

Detect anomalous sales that undermine your predictive models.

Exclude invalid sales with legible and defensible rules.

Pipeline screenshot

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.

Export screenshot

Export for GIS & CAMA

Output parcel data in GIS-ready formats for seamless import into ArcGIS, QGIS, and Felt.

Export tabular data to Database and CAMA-friendly formats like CSV, Excel, Parquet, and more.

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.

Get Started