FileBrixNo upload · Private
Processed locally — your file never leaves your device

GeoJSON Bounding Box

Get the bounding box (extent) of any GeoJSON, KML or GPX file — entirely in your browser.

Drop a GeoJSON, TopoJSON, KML, KMZ, GPX, zipped Shapefile or CSV file hereor click to choose a file from your deviceNothing is uploaded — the file is detected and processed entirely on your device.

How it works

  1. Select or drop a .geojson, .kml or .gpx file.
  2. Click Bounding Box to compute the extent locally.
  3. Preview the rectangle on the map and download it as GeoJSON.

Frequently asked questions

What is a bounding box?
The smallest upright rectangle that contains every feature in your data, given as its west, south, east and north edges. It's the usual way to describe where a dataset is, and what map servers and catalogues expect.
Is my file uploaded anywhere?
No. The extent is computed on your device with Turf.js — nothing is ever sent to a server.
What do I get back?
A GeoJSON polygon of the rectangle, which you can download or preview on the map. The corner coordinates are shown alongside it.
Does it work with KML and GPX too?
Yes. Those are converted to GeoJSON locally first, so the bounding box is computed the same way.