All GeoJSON files carry "crs": {... "EPSG::3857"} and Web-Mercator metre coordinates. RFC 7946
mandates WGS84 lon/lat and forbids the crs member, so no standard web mapping library reads them
as-is. We reproject on import.
Ask: write RFC 7946 GeoJSON. RFC7946=YES drops the crs member and sets
7-decimal precision.
gdf.to_crs(4326).to_file(path, driver="GeoJSON", RFC7946="YES")
Note: Coordinates currently arrive rounded to whole numbers. The same rounding applied to degrees
would be a ~100 km error, so please don't switch CRS without raising precision.
SuperBlockify already writes UTM per city (EPSG:32631 for Brussels), which is metrically correct
and just needs the same conversion for the web.
All GeoJSON files carry
"crs": {... "EPSG::3857"}and Web-Mercator metre coordinates. RFC 7946mandates WGS84 lon/lat and forbids the
crsmember, so no standard web mapping library reads themas-is. We reproject on import.
Ask: write RFC 7946 GeoJSON.
RFC7946=YESdrops thecrsmember and sets7-decimal precision.
Note: Coordinates currently arrive rounded to whole numbers. The same rounding applied to degrees
would be a ~100 km error, so please don't switch CRS without raising precision.
SuperBlockify already writes UTM per city (EPSG:32631 for Brussels), which is metrically correct
and just needs the same conversion for the web.