Tools for converting Shapefies
- MyGeoData - Free Online GIS Data Converter
- QGIS - OpenSource Desktop Application for Windows, Mac, Linux
Conversion Tips (using QGIS) - Where possible, stick to standard “lat,lon” coordinate system: WGS 84 (EPSG:4326)
- The “Simplify Geometries” tool can reduce the size of the data before exporting.
Experiment with tolerances around 0.0002 - 0.0005 (assuming WGS 84 coordinates). - When exporting large files, tick “Skip attribute creation” to save space.
- When saving as GeoJSON, you can reduce “coordinate precision” to 4.
To make GeoJSON files even smaller, delete all space characters (20% saving!). - If anyone can work out how to remove coastlines, that will make a huge difference…
Example Geometry Files - States of USA (48 contiguous states)
- Counties of USA
- Counties of Puerto Rico
- Counties of Great Britain (“soon”)
- Counties of Northern Ireland
- Regions of Philippines