GeoJSON Validator — free & private
Paste GeoJSON or upload a .geojson/.json file. Validate Polygon/MultiPolygon rings, holes, duplicates, self-intersections, and get anti-meridian hints with a live map preview.
FAQ
Does this upload my GeoJSON?
No. Validation and fixes run entirely in your browser. Nothing is uploaded.
What GeoJSON inputs do you accept?
FeatureCollection, Feature, or a bare geometry (including GeometryCollection). You can also upload .geojson or .json files.
What does the validator do with FeatureCollections?
It extracts valid geometries, ignores features with missing/invalid geometry (warning), and validates ALL remaining features together. GeometryCollections are flattened for counting and WKT export.
What issues are checked?
Polygon/MultiPolygon deep checks include: ring closure, minimum vertices (≥4 when closed), zero-area rings, holes outside their outer ring (error), holes touching the outer boundary (warning), self-intersections (error), duplicate ring pairs (warning), and RFC 7946 winding hints. Across ALL geometry types it also checks non-finite coordinates (error) and lon/lat out-of-range (warning, assuming WGS84).
Why do I see an “anti-meridian” warning?
If the validator detects longitude jumps >180°, the geometry likely crosses the anti-meridian (±180°). Winding fixes are disabled in that case because rewinding can break polygons unless you split them first.
Which geometry types are supported?
Polygon and MultiPolygon get full ring/hole validation + fixes. Other types are still accepted and included, but only basic coordinate checks are applied.
What fixes can I apply here?
Close rings, remove consecutive duplicate vertices, drop zero-area rings, enforce RFC 7946 winding (disabled when anti-meridian crossing is likely), and drop duplicate rings (holes) within a polygon.
Will fixes repair self-intersections or holes outside the polygon?
No. Those are topology problems and usually require interactive repair tools. This page focuses on safe, deterministic fixes and clear diagnostics. Use “Continue in Editor” to open the full editor with your geometry and fix topology issues there.
Can I export as WKT too?
Yes. The validator always provides an alternate export (GeoJSON ↔ WKT). Multiple geometries can export as a GeometryCollection, or one-WKT-per-feature in WKT mode.
Want to order satellite data for your polygons?
ClearSKY uses data fusion to deliver cloud-free imagery and robust time series at scale. Upload your polygons and place orders in minutes.