Geodata file validator

Check GeoJSON, KML, GPX and other geospatial files against their specifications and catch structural errors before they break your map.

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Frequently asked questions

What makes a GeoJSON file valid?

Valid GeoJSON conforms to RFC 7946: a top-level FeatureCollection, Feature or geometry object; positions ordered [longitude, latitude]; longitudes within ±180° and latitudes within ±90°; polygon rings closed (first and last position identical); and right-hand-rule winding for exterior rings. The validator checks structure, coordinate ranges and geometry against these rules.

Why does my polygon fail validation?

The two most common causes are an unclosed ring — the first and last position of a linear ring must be identical — and a self-intersecting boundary, where the ring crosses itself. RFC 7946 also expects exterior rings counter-clockwise and holes clockwise; many renderers tolerate reversed winding but strict validators flag it.

What does "coordinates out of range" mean?

It means a position has a longitude outside ±180° or a latitude outside ±90°. That usually signals swapped lat/lng (a latitude value sitting in the longitude slot, or vice versa) or data that's actually in a projected CRS measured in metres rather than degrees — in which case it needs reprojecting to WGS 84 first.