100% Private — Runs in Your Browser

GeoJSON Simplifier

Reduce vertex count and file size in GeoJSON LineStrings and Polygons using the Douglas-Peucker algorithm. Free, private, no upload to server.

Drag & drop your GeoJSON file here

or click to browse

Frequently Asked Questions

What algorithm does this simplifier use?

The Douglas-Peucker algorithm, the same industry-standard method used by desktop GIS tools. It recursively removes points that fall within a given perpendicular distance ("tolerance") of a simplified line, preserving the overall shape while reducing vertex count.

What tolerance should I use?

Tolerance is in coordinate degrees, applied directly to your data's coordinate values. Start small (0.0001–0.001) for web maps where you want to preserve detail, and increase toward 0.01+ only if you need an aggressive reduction for thumbnails or overview maps. Always preview the vertex/file-size change before downloading.

Which geometry types are simplified?

LineString, MultiLineString, Polygon, and MultiPolygon geometries are simplified. Point and MultiPoint geometries are always passed through unchanged, since a single point has nothing to simplify.

Is my data private?

Yes, completely. All simplification happens inside your browser using JavaScript. Your file is never uploaded to any server.

Want to preview the simplified shape on an interactive map before downloading?

Open GeoDataTools App