GeoJSON Buffer Tool
Create buffer zones around GeoJSON points, lines and polygons — km, m, mi or nm, computed locally in your browser with nothing uploaded. Free, no sign-in.
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 points / lines / polygons → buffered GeoJSON
How to use
Section titled “How to use”- Paste your GeoJSON into the input box, or click “or load a file” to pick a .geojson/.json file.
- Set the buffer distance and units (negative values shrink polygons inward), plus the circle detail (segments per quadrant).
- Generate, preview the result on the map (tick “Show original” to compare before/after), then download the buffered GeoJSON.
Key details and limits
Section titled “Key details and limits”- Built on turf.js (MIT).
- Input must be WGS84 longitude/latitude; reproject other CRS first (e.g. with GeoJSON Reproject) — otherwise buffers are silently misplaced.
- Negative distances shrink polygons inward; a negative radius on point/multi-point/line features is rejected up front (they have no inward side, and mixed inputs would silently drop them). Zero and non-finite distances are rejected.
Common use cases
Section titled “Common use cases”- Paste points/lines/polygons (or load a file) → set a radius → generate buffers → compare before/after on the map
- Buffer GPS track points by 500 m to see service coverage, then dissolve the result into one continuous zone.