About this tool & the legal fine print

What this is

This is a free, fully automated tool that compares a Cook County residential property's assessed value against similar nearby properties, using the Cook County Assessor's own public open data. It shows you the comparison and the numbers behind it. That's all it does.

What this is not

Who runs it

Aiden Buck
1001 Bishop St., Ste 2685a, Honolulu, HI 96813, US

We are not attorneys, not appraisers, and not affiliated with Cook County.

Data & method

Data comes from the Cook County Assessor's datasets on datacatalog.cookcountyil.gov, cached nightly. Comparables are limited to the same neighborhood code and the same class, then ranked by similarity; values are compared as assessed value per square foot. The full method and source code are open for inspection.