100% Private — Runs in Your Browser

GeoJSON CRS / Reprojection Tool

Reproject a GeoJSON file between coordinate reference systems — WGS84, Web Mercator, UTM, and Lambert-93. Free, private, no upload to server.

Drag & drop your GeoJSON file here

or click to browse

Just converting a single point? Try our Coordinate Converter →

Frequently Asked Questions

Which coordinate reference systems are supported?

WGS84 (EPSG:4326), Web Mercator (EPSG:3857), UTM zones 33N/34N/35N, French Lambert-93 (EPSG:2154), and ETRS89 UTM zones 32N/33N. This tool uses the same reprojection engine as the CRS switcher in the full GeoDataTools app.

How is the input CRS detected?

If your GeoJSON has a crs member, that EPSG code is used. Otherwise the coordinate ranges are inspected — values within -180/180 and -90/90 are assumed to be WGS84, and much larger values are assumed to be Web Mercator. You can always override the detected value before reprojecting.

Does reprojection change my file's structure?

No. Only the coordinate values are transformed. Feature properties, geometry types, and nesting are left untouched, and the output crs member is updated to reflect the new CRS.

Is my data private?

Yes, completely. All reprojection happens inside your browser using the proj4js library. Your file is never uploaded to any server.

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

Open GeoDataTools App