Public ArcGIS MapServer endpoint for King County parcel data. URL, supported fields, and a working sample query — copy it, or open it directly in the UrbanKit parcel lookup tool.
https://gismaps.kingcounty.gov/arcgis/rest/services/Property/KingCo_Parcels/MapServer/0/query?where=PIN='0000200001'&outFields=*&f=jsonOpen this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| PIN | Parcel Identification Number | YES |
| MAJOR | Major (first 6 of PIN) | YES |
| MINOR | Minor (last 4 of PIN) | YES |
King County publishes parcel polygons under PIN/MAJOR/MINOR identifiers — no owner or address fields on this layer. For owner-name search in King County, use the Assessor's separate property database.
King County GIS Center — https://kingcounty.gov/services/gis.aspx
/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 this 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.