# Cook County, IL property data

> Cook County, IL parcel data: 1,415,409 parcels with tax assessor records, building permits, zoning, historic designations, building codes, via API, MCP server and vector tiles.

Source: https://www.parceled.ai/coverage/illinois/cook-county  
Publisher: Parceled (https://www.parceled.ai)  
Updated: 2026-10-30

Parceled covers 1,415,409 parcels in Cook County, IL, with tax assessor records, building permits, zoning, historic designations, building codes and hail history available through one API and MCP server. Tax assessor attributes are present for 100% of parcels (owner names on 100% of those records, year built on 0%).

- **Parcels:** 1,415,409
- **County FIPS:** 17031
- **Snapshot:** October 30, 2026

## What property data is available for Cook County?

| Dataset | Cook County |
| --- | --- |
| Parcel boundaries | 1,415,409 parcels |
| Tax assessor records | 1,748,663 records (100% of parcels) |
| Owner name and mailing address | 100% of assessor records |
| Market or assessed value | 0% of assessor records |
| Year built | 0% of assessor records |
| Last sale date | 0% of assessor records |
| Building permits | 5,171 permits since 2026, latest October 28, 2026 |
| Roofing permits | 298 |
| Zoning | 56 zoning jurisdictions |
| Buildable-area screens | Yes |
| Historic designations | 628 |
| Adopted building codes | 6 jurisdictions |
| Hail history (radar) | Yes, every county in the contiguous US |

## How do I query Cook County property data?

Bulk-search every parcel in the county with `search_properties` using `state: "IL"` and `county: "031"` (the county FIPS code 17031), or look up one address with `search_parcels`. Check any single property for free with `check_availability`.

```json
{
  "name": "count_properties",
  "arguments": { "state": "IL", "county": "031" }
}
```

## Frequently asked questions

### How do I find who owns a property in Cook County?

Search the address on the Cook County assessor's website, or query Parceled's `search_parcels` for owner name and mailing address. See [how to find a property owner by address](https://www.parceled.ai/guides/how-to-find-property-owner-by-address).