Nassau County, NY parcel data download

Download Nassau County, New York parcel data - 410,534 parcels with standardized boundaries and available property fields. Review county-specific completeness before checkout. Instant delivery in Shapefile, FileGDB, GeoPackage, GeoJSON & CSV. $100 per county.

Data freshness: NYS ITS/ORPTS 2025 assessment roll attributes; NYS parcel centroid service publication date: May 2026; last loaded into LandAI on 2026-05-13.

Every purchase includes all five export formats (Shapefile, FileGDB, GeoPackage, GeoJSON & CSV), standardized to the LandAI parcel schema with WGS84 (EPSG:4326) geometry. After checkout you choose which formats to generate and download them for 45 days.

What's in the Nassau County dataset

Field completeness measured across 410,534 active parcels (NYS ITS/ORPTS 2025 assessment roll attributes; NYS parcel centroid service publication date: May 2026; last loaded into LandAI on 2026-05-13):

FieldCoverage
Owner names99.7%
Site addresses100%
Owner mailing addresses99.7%
Deeded acres99.7%
Calculated (GIS) acres100%
Assessed total value99.7%
Market total value99.7%

These are 7 of the 48 standardized fields in the LandAI parcel schema. Live per-field completeness for every field is shown on this page's interactive view.

Nassau County parcel data FAQ

How many parcels are in Nassau County, NY?

Nassau County, New York has 410,534 active parcels in the LandAI dataset (source data as of 2025).

What fields are included in Nassau County parcel data?

The dataset uses LandAI's standardized parcel schema. Field availability varies by source and record. Current measured completeness includes owner names (99.7%), site addresses (100%), owner mailing addresses (99.7%), deeded acres (99.7%), calculated (GIS) acres (100%), assessed total value (99.7%), market total value (99.7%).

What formats can I download Nassau County parcel data in?

Shapefile, FileGDB, GeoPackage, GeoJSON & CSV. Every $100 county purchase includes all five formats; you choose which to generate after checkout and can re-download for 45 days.

How current is the Nassau County parcel data?

NYS ITS/ORPTS 2025 assessment roll attributes; NYS parcel centroid service publication date: May 2026; last loaded into LandAI on 2026-05-13.

Does Nassau County parcel data include owner names?

99.7% of Nassau County parcels currently include a normalized owner name. Mailing-address coverage is measured and reported separately when the source provides it.

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