US Counties Boundaries — GeoJSON Download (3,233 Counties)
Quick answer: This page hosts all 3,233 US county and county-equivalent boundaries as a single public-domain GeoJSON file of about two megabytes, with a map preview and one-click download.
About this dataset
Every US county and county equivalent as one hosted GeoJSON — 3,233 units with FIPS-style identifiers, ready to join census, health, or election data and map in the browser.
Download US county boundaries as GeoJSON: 3,233 county equivalents covering all 50 states, the District of Columbia, and Puerto Rico. County-level data is where most US public datasets live — census population, CDC health indicators, election results, USDA agriculture — so this layer is the join target for a large share of American spatial analysis. Each feature carries shapeName (Highland, Alpine, Escambia, …), shapeISO where the source publishes one, and a stable shapeID, and the geometry is simplified to about a 1 km tolerance so the whole national county set fits in roughly two megabytes instead of the tens of megabytes of the full-detail file.
Data source: US Census Bureau MAF/TIGER Database via geoBoundaries
How to download
- 1 Preview the county layer on the map above — 3,233 polygons render from a single file.
- 2 Download the GeoJSON and open it in QGIS, ArcGIS, or GeoDataViewer Studio.
- 3 Join your county table on shapeName (or convert to a 5-digit FIPS GEOID for a stricter join).
- 4 Use the full-detail file when you need exact county area or boundary-length measurements.
Hosted simplified GeoJSON (1.95 MB)
3,233 counties, web-ready, public domain — used by the map preview above
Full-detail GeoJSON from geoBoundaries
Every original vertex, ~46 MB — for precise area and distance work
US Census cartographic boundary files
Official source with multiple resolutions and vintages
geoBoundaries USA metadata
Machine-readable licence, source, and download record
FAQ
How many counties does the file contain?
3,233 county equivalents. That is the 3,143 counties and county equivalents of the 50 states and DC plus the 78 municipios of Puerto Rico, counted the way the Census Bureau tabulates them.
Does the file include FIPS codes?
The hosted layer keeps the geoBoundaries identifier fields (shapeName, shapeISO, shapeID) and does not carry a 5-digit FIPS GEOID. For a strict FIPS join, use the Census Bureau cartographic boundary file linked above, which ships GEOID directly.
Is a two-megabyte county file accurate enough for analysis?
For mapping, joins, and visual comparison, yes — simplification preserves every county and its topology. For computing exact land area, perimeter, or buffering at parcel scale, download the full-detail file instead.
Can I filter to a single state's counties?
Yes. Open the file in GeoDataViewer Studio and filter on shapeID or shapeName, or select the state's features on the map — the attribute table and feature inspector stay in sync with the map selection.