What this site is
GeoJason is 12 tools and 7 converters for working with GeoJSON, plus 16 guides about the format. You can view a file on a map, check it against RFC 7946, convert it to and from KML, WKT, GPX and plain coordinates, and run the common spatial operations: buffer, clip, union, merge, simplify, and area, length, centroid and bounding box calculations.
How the tools work
Every tool runs in your browser without needing to upload data to a remote server. The spatial calculations come from Turf.js, maps render with Leaflet over OpenStreetMap tiles, and KML and GPX parsing uses togeojson.
What the tools do not do
- No reprojection. GeoJSON is WGS 84 by definition. Data in another coordinate system has to be reprojected before it arrives here.
- No topology-aware simplification. Each geometry is simplified on its own, so shared borders between neighbouring polygons can drift apart. Mapshaper is the tool for that job.
- Clipping is areal. Polygons are clipped to a boundary outline. Points and lines are handled against its bounding box instead, and the tool says so when it happens.
- Everything is bounded by your browser. There is no streaming and no worker pool. Files in the tens of megabytes will be slow, and very large ones will run the tab out of memory.
Where a tool cannot handle an input, it says so. Silent failures were removed deliberately; a converter that returns nothing without explaining why is worse than one that refuses.
Contact
Questions, corrections, bug reports and suggestions go to info@geojason.com. The contact page explains what to include so a problem can be reproduced.
Claims that turned out to be wrong are logged on the corrections page, and the data behind every measured page is published on the datasets page. The privacy policy and the terms of service govern use of the site, and the sitemap lists every page on it.