Illinois · FIPS 17031 · County seat: Chicago
Cook County, IL GIS & Parcel Viewer
Here is the direct link to the county parcel map covering Cook County, IL: CookViewer. Below you'll find basic facts about the county, steps for using the viewer, and nearby counties.
Open the Cook County parcel map ↗
Opens maps.cookcountyil.gov in a new tab. We link out and never embed or copy parcel data.
Cook County at a glance
| Official map | CookViewer |
|---|---|
| Type | County-run map |
| Website | maps.cookcountyil.gov |
| Access | Free, no login (checked Oct 2026) |
| County seat | Chicago |
| Population | 5,087,072 (2023 Census Bureau estimate) |
| Land area | 945 sq mi |
| FIPS code | 17031 |
Who runs this map
This map is published by or for Cook County itself, so it reflects the local parcel layer rather than a third-party copy. Our October 2026 check found the map open to the public, with no account or payment needed.
Searching for a parcel, step by step
- Press the button above to open the county's own web map.
- Search for the property or pan and zoom to it.
- Click the lot to bring up what the county publishes about it.
- Look for print or measure tools if you need a quick map or rough size.
If an address search comes up empty, try the parcel number from a tax bill or deed instead, or click the lot on the map.
The county in brief
Cook County had an estimated 5,087,072 residents in 2023, according to the Census Bureau. With about 945 square miles of land, that works out to roughly 5,383 people per square mile. That makes it the most populous of Illinois's 102 counties. Census maps also count about 690 square miles of water inside its boundary. Chicago serves as the county seat.
Nearby parcel maps
Parcels close to the edge of Cook County can fall in the next county over. Neighboring counties:
- DuPage County
- Kane County
- Lake County
- McHenry County
- Will County
- Berrien County, MI
- Lake County, IN
- Porter County, IN
Related guides
Maps vs. surveys
The lines you see online are approximate. They're good for finding a lot and its parcel number, but a legal boundary question needs the recorded plat or a surveyor.