Point in Polygon Tester
Test if a point is inside, outside, or on the boundary of a polygon.
🔒 All calculations happen locally in your browser. Your coordinates never leave your device.
Paste GeoJSON coordinates array (outer ring). Format: [[lon,lat],...]
How It Works
Uses the ray-casting algorithm to determine point-in-polygon containment. A ray is cast from the point to infinity; if it crosses an odd number of polygon edges, the point is inside.
Supports: Simple Polygon and MultiPolygon (each polygon tested independently).
Privacy: Pure geometric computation in JavaScript. No external services.