GeoJSON Simplify Tool
Simplify GeoJSON vertices in your browser: fast Douglas-Peucker, topology-preserving, keep-percentage, or combined modes — then check the map preview and before/after vertex stats. Free, no sign-in, nothing uploaded.
Processing and data safety
Section titled “Processing and data safety”This tool runs entirely in your browser — your files are never uploaded to a server.
Input and output
Section titled “Input and output”- Formats: GeoJSON
- Flow: GeoJSON → simplified GeoJSON
How to use
Section titled “How to use”- Paste your GeoJSON text into the input area, or click “or load a file” to pick/drop a .geojson/.json file.
- Pick a mode: set the tolerance for Fast / Topology-preserving, or set a keep percentage and algorithm (Visvalingam effective area / perpendicular distance) for the target and combined modes.
- Simplify, inspect the result on the map preview and the before/after stats line, then download.
Key details and limits
Section titled “Key details and limits”- Fast-mode tolerance is in coordinate units, not meters, for geographic data.
- Simplify is geometric only.
- Topology-preserving mode (shared edges stay aligned) is available alongside fast Douglas-Peucker.
Common use cases
Section titled “Common use cases”- Paste or load GeoJSON → set a tolerance or a keep-percentage target → inspect the preview → simplify
- Lighten a large boundary layer for a web map: keep 20% of vertices with the combined topology × keep mode — shared edges stay seamless and the stats line shows…