geojson-precision

Python function and command line interface to adjust the precision of GeoJSON coordinates.

The GeoJSON specification recommends 6 decimal places for latitude and longitude which equates to roughly 10cm of precision. You may need slightly more for certain applications; 9 decimal places would be sufficient for professional survey-grade GPS coordinates.

But many GeoJSON writers provide excessive precision, up to 15 decimal places which is so microscopically small as to be irrelevant for any geospatial application. This excessive precision inflates file sizes, reduces human readability, wastes bandwidth, and increases the chances for floating-point inconsistencies.

So instead of

{
    "geometry": {
      "type": "Point",
      "coordinates": [
        100.2380000001,
        5.3120000001
      ]
    },
    "type": "Feature",
    "properties": {}
}

Use geojson-precision to make coordinate precision a bit more reasonable

$ geojson-precision -p 2 < example.geojson

{
  "type": "FeatureCollection",
  "features": [
    {
      "geometry": {
        "type": "Point",
        "coordinates": [
          100.24,
          5.31
        ]
      },
      "type": "Feature",
      "properties": {}
    }
  ]
}

For some large geojson feature collections, going from 15 to 6 decimal places can reduce the file size by roughly 50%.

perrygeo/geojson-precision

geojson-precision