Update: Check out Placemark, a new and better map editor with great GeoJSON support!
geojson.io is for drawing, changing, and sharing GeoJSON-formatted map data.
Save as a GitHub Gist and share a link. Hit
Cmd-S to do it quickly.
Edit the JSON properties in GeoJSON features easily.
Line-specific JSON-validation errors from jsonlint.
Line-specific GeoJSON-validation errors from geojsonhint.
Use geojson.io with modern mapping tools, like TileMill, MapBox.js, GitHub, and Shapely.
It’s made of open source: Leaflet.draw, MapBox.js, CodeMirror, and a new library I wrote called geojsonhint, that does GeoJSON validation.