New Jersey · FIPS 34021 · County seat: Trenton
Mercer County, NJ GIS & Parcel Viewer
Here is the direct link to the county parcel map covering Mercer County, NJ: the Mercer County parcel map. Below you'll find basic facts about the county, steps for using the viewer, and nearby counties.
Open the Mercer County parcel map ↗
Opens viewer.myidv.com in a new tab. We link out and never embed or copy parcel data.
Map and county facts
| Official map | Mercer County parcel map |
|---|---|
| Type | County-run map |
| Website | viewer.myidv.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Trenton |
| Population | 381,671 (2023 Census Bureau estimate) |
| Land area | 224 sq mi |
| FIPS code | 34021 |
Who runs this map
Mercer County runs this viewer (directly or through a contracted vendor), which makes it the closest thing to the source for local parcel lines. 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.
Have a tax bill handy? The parcel or account number on it is usually the fastest way to search.
About Mercer County
Census Bureau figures put Mercer County at about 381,671 people (2023 estimate) on roughly 224 square miles of land, which is about 1,704 residents per square mile. Among New Jersey's 21 counties, it is the 12th largest by population. Its county seat is Trenton.
Counties next to Mercer County
Parcels close to the edge of Mercer County can fall in the next county over. Neighboring counties:
A note on accuracy
Keep in mind that a GIS parcel layer is a tax map, not a survey. For exact boundaries, look at the recorded deed and plat or hire a licensed land surveyor.