Public ArcGIS MapServer endpoint for Williamson County parcel data. URL, supported fields, and a working sample query — copy it, or open it directly in the UrbanKit parcel lookup tool.
PropertyNumberProperty Number (R-number)PARCELIDParcel IDFullNameOwner Name (formatted)PrimaryOwnerPrimary Ownercurl -s 'https://gis.wilco.org/arcgis/rest/services/public/county_wcad_parcels/MapServer/0/query?where=UPPER(FullName)%20LIKE%20UPPER('%25SMITH%25')&outFields=PropertyNumber,FullName,MailingAddress&returnGeometry=false&f=json&resultRecordCount=10'https://gis.wilco.org/arcgis/rest/services/public/county_wcad_parcels/MapServer/0/query?where=UPPER(FullName) LIKE UPPER('%SMITH%')&outFields=PropertyNumber,FullName,MailingAddress&returnGeometry=false&f=json&resultRecordCount=10Open this URL in a browser tab to see the raw ArcGIS JSON response.
| Field name | Label | Searchable |
|---|---|---|
| PropertyNumber | Property Number (R-number) | YES |
| PARCELID | Parcel ID | YES |
| FullName | Owner Name (formatted) | YES |
| PrimaryOwner | Primary Owner | YES |
| MailingAddress | Mailing Address | NO |
Williamson County, Texas (Round Rock / Georgetown / Cedar Park, north Austin metro, pop. ~750K) serves a parcel layer updated daily from Williamson Central Appraisal District (WCAD) via Williamson County GIS (gis.wilco.org). Owner name is available as FullName (formatted) and PrimaryOwner, with NameFirst/NameMiddle/NameLast and CNVYNAME (conveyance name) components; mailing is MailingAddress; identifiers are PropertyNumber (R-number, e.g. R-01-1100-0012-0009) and PARCELID. Owner search uses UPPER(FullName) LIKE. Verified live 2026-05-30 (FullName = GOVELLAN, JUAN). Texas Tax Code §25.025 confidentiality provisions apply to protected persons.
Williamson County GIS / Williamson Central Appraisal District (WCAD) — https://www.wcad.org/
Williamson County's WCAD Parcels layer exposes a parcel identifier (Parcel ID) and owner names (Owner Name (formatted), Primary Owner). Use it for owner-name lookups and PIN-keyed record pulls. 4 of 5 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 2026-05-30.
/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 Williamson 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.