Public ArcGIS MapServer endpoint for Fairfax County parcel data. URL, supported fields, and a working sample query — copy it, or open it directly in the UrbanKit parcel lookup tool.
https://www.fairfaxcounty.gov/mercator/rest/services/OpenData/OpenData_A9/MapServer/0PINParcel Identification NumberPARCEL_KEYParcel Key (numeric)curl -s 'https://www.fairfaxcounty.gov/mercator/rest/services/OpenData/OpenData_A9/MapServer/0/query?where=PIN+LIKE+%270304%25%27&outFields=PIN,PARCEL_TYPE&returnGeometry=false&f=json&resultRecordCount=10'
https://www.fairfaxcounty.gov/mercator/rest/services/OpenData/OpenData_A9/MapServer/0/query?where=PIN+LIKE+'0304%'&outFields=PIN,PARCEL_TYPE&returnGeometry=false&f=json&resultRecordCount=10Open this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| PIN | Parcel Identification Number | YES |
| PARCEL_KEY | Parcel Key (numeric) | YES |
| PARCEL_TYPE | Parcel Type (ORDINARY / CONDO) | NO |
| SRC_CONTROL | Source Control | NO |
Fairfax County (Northern Virginia, pop. 1.15 million) is the most populous jurisdiction in Virginia and covers 406 square miles, entirely distinct from Fairfax City -- a separate independent city (FIPS 51600) that sits geographically within the county but is governed and assessed independently. The county-direct parcel layer at fairfaxcounty.gov/mercator/rest/services/OpenData/OpenData_A9/MapServer/0 exposes PIN, PARCEL_KEY, PARCEL_TYPE (ORDINARY vs. CONDO), and SRC_CONTROL -- but no owner name. Fairfax keeps ownership data in a non-spatial table not exposed on this REST endpoint. For owner-name lookup, use the Fairfax County Real Estate Assessment Database at realestate.fairfaxcounty.gov; it supports search by address, parcel ID, and owner name. The GIS/Property MapServer at fairfaxcounty.gov/euclid/rest has 54 layers (parcels, tax districts, easements, flood zones, annotations) but also does not surface owner in the queryable parcel layer. PIN format is space-padded with section/block/lot grouping (e.g., '0304 39 0029'). Verified 2026-05-11: 369,267 polygon parcels. Updated daily from county cadastral.
Fairfax County GIS Division (Department of Information Technology) — https://www.fairfaxcounty.gov/maps/
Fairfax County's Parcels layer exposes a parcel identifier (Parcel Identification Number). Use it for PIN-keyed record pulls (owner-name search lives on a separate assessor system). 2 of 4 listed fields accept queries; the rest are returned on read but not indexed for search. Served as an ArcGIS MapServer layer, which supports query operations but not write operations; last verified 2026-05-11.
/query?where=…&outFields=*&f=jsonto the URL. The sample query above is a working example you can paste into a browser tab to see the raw JSON response.Counties publish parcel data through their own ArcGIS Server installations, each with its own schema. One county uses APN, another uses PIN, a third uses PARCEL_ID. Some expose owner names; others keep them on a separate assessor's portal. The searchable fields list above reflects what Fairfax County actually publishes — not what you might expect from a national standard (there isn't one).
For background, see What is an APN?
Many county servers allow public reads but block browser cross-origin requests. The UrbanKit parcel lookup tool fetches directly from your browser; if it works there, the layer is technically public. For your own integration, you may need a same-origin proxy or server-side fetch.
Possibly — counties move services without warning. We re-verify entries weekly and flag stale ones. If you're seeing a fresh 404, please let us know and we'll update the listing.
Most are. Public ArcGIS layers don't typically rate-limit individual reads, but heavy programmatic use can trigger throttling at the host level. Be respectful — query what you need.