Paste GeoJSON below to check it for structural errors — unclosed polygon rings, wrong coordinate nesting, invalid types — with clear explanations of what’s wrong and where.
Checked locally in your browser — your GeoJSON is never sent to our server.
Computed entirely in your browser — nothing you enter here is sent to our server.
Checking…
How This Works
This checks your GeoJSON against the core GeoJSON specification (RFC 7946): every geometry type’s coordinates must be nested to the correct depth ending in [longitude, latitude] pairs, Features must have a “properties” key, and Polygon rings must be closed — their first and last position must be identical. Problems are reported as either errors (the GeoJSON is invalid) or warnings (technically questionable but often still usable).
FAQ
Why is an unclosed polygon only a warning, not an error?
Many tools (including this site’s own map rendering) will still draw an unclosed ring by implicitly closing it, so it often “works” in practice even though it’s not strictly spec-compliant — worth fixing, but not always fatal.
Is my data uploaded anywhere?
No. Validation happens entirely in your browser — nothing you paste here is sent to our server.