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GeoJSON Validator

Upload a GeoJSON file and get an instant validation report — JSON syntax, RFC 7946 structure, unclosed polygon rings, self-intersecting geometry, and coordinates outside the valid WGS84 range (a common sign of a lon/lat swap).

Validate your file

Drop GeoJSON file here or click to browse

.geojson or .json · max 9 MB · nothing is stored
What the validator checks
1

JSON syntax & RFC 7946 structure

Valid JSON, correct top-level type (FeatureCollection/Feature/geometry), required features/geometry/coordinates fields per the GeoJSON spec.

2

Geometry topology

Unclosed polygon rings (first/last coordinate must match), self-intersecting polygons ("bowtie" shapes), and other topologically invalid geometry — checked with the same geometry engine used by QGIS and PostGIS.

3

Coordinate range sanity

GeoJSON requires WGS84 — coordinates outside lon ±180 / lat ±90 are flagged as a warning, since it's almost always a longitude/latitude swap or a file that's actually in a projected coordinate system (meters), not degrees.

Common questions
What's the difference between an error and a warning?+

Errors mean the file breaks the GeoJSON spec (invalid JSON, wrong structure, unclosed polygon ring) — most GIS software will reject or mis-render it. Warnings flag things that are structurally valid JSON but very likely wrong in practice (self-intersecting polygons, out-of-range coordinates) — worth checking, but some tools will still open the file.

Why does my file show "coordinates outside valid WGS84 range"?+

GeoJSON coordinates are [longitude, latitude] — in that order. The most common cause is coordinates written as [latitude, longitude] instead, or a file exported from a projected coordinate system (UTM, State Plane — meters, not degrees) without reprojecting to WGS84 first. See our points-in-the-ocean guide for the full diagnosis.

Is my file uploaded or stored anywhere?+

Your file is sent to GISGP's server for validation and the report is returned immediately — nothing is saved or logged beyond the request itself, and there's no database record of the file's content.

How do I fix a self-intersecting polygon?+

Open the file in QGIS (free) and use Vector → Geometry Tools → Fix Geometries, or in ArcGIS Pro use the Repair Geometry tool. Both rebuild the polygon's rings so they no longer cross themselves.

Import valid GeoJSON into ArcGIS Online

Once your GeoJSON passes validation, GISGP can convert it to Shapefile, KML, or publish it directly as an ArcGIS Online Feature Layer.

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Related: GeoJSON → Shapefile · Shapefile → GeoJSON · CSV → GeoJSON · GeoJSON Viewer