I have this GeoJSON file which uses the following projection: EPSG:28992. I want to convert this to EPSG:3857 but I don't have GIS software available. I have tried ogre, but when I first convert it to a shapefile and then back to GeoJSON using the aforementioned projections, it still shows coordinates with extremely high numbers (476628.5890141478,6820821.561640609 etc). The same applies when I try converting it using reproject.

In both cases when I try loading the converted files into geojson.io it fails -- it doesn't show on the map. In EPSG:3857, I'm expecting something like 4.30, 52.08 instead of coordinates that are in the hundreds of thousands.

Any idea what I am doing wrong or how to get the right values?

  • 1
    Might be an obvious question, but what is keeping you from downloading and using QGis? – Erik Jan 27 '19 at 21:13
  • With EPSG:3857 you must expect coordinate values in range -20026376.39 -20048966.10 - 20026376.39 20048966.10 epsg.io/3857 – user30184 Jan 27 '19 at 21:17
  • EPSG:3857 has coordinates in meters, so high numbers (476628.5890141478,6820821.561640609 etc) are expected. If you want coordinates in decimal degrees (i.e longitude and latitude), reproject to EPSG:4326. – user2856 Jan 27 '19 at 23:30
  • Wait.. I'm quite confused, in Leaflet I was under the impression that I must use EPSG 3857 but in the examples I see decimal degrees being used. I guess this is another question in itself. I will post this separately. – user135947 Jan 28 '19 at 4:15
  • The geojson files generally should be in WGS84 (EPSG:4326). If I am not mistaken, by default, leaflet expects that and will reproject the data internally to EPSG:3857 – FSimardGIS Jan 28 '19 at 4:22

You will have to reproject your file to EPSG:4326 (latitudes and longitudes) if you want to see it in geojson.io.

EPSG:3857 is not a coordinate system that uses longitudes and latitudes. It is a projected coordinate system using meters as units. Coordinates in EPSG:3857 can go up to about 20,000,000.

  • epsg:4326 is lat/lon, not lon/lat see the EPSG registry ~ epsg-registry.org/export.htm?wkt=urn:ogc:def:crs:EPSG::4326 – nmtoken Jan 28 '19 at 10:58
  • @nmtoken You're right, thanks for mentioning this. For the sake of the coordinate conversion, I think it does the trick for the OP's needs, but indeed, as you say, technically 4326 is lat,lon, and geojson should be in CRS:84 (lon, lat) revesed axis order from the 4326 definition. – FSimardGIS Jan 28 '19 at 17:18
  • Quick question: if you use a program like ArchGIS and you select EPSG:4326, will it be compatible with geojson? Or is it a problem that lat/lon are in reverse? If so, what setting is required in this kind of program when exporting the dataset? – user135947 Jan 29 '19 at 8:17
  • ArcGIS handles the conversion correctly, it writes x first (longitude), then y (latitude) in the geojson file, from a dataset in WGS84. So it writes the coordinates to respect the format output, same principle as, for example, for KML files as well. – FSimardGIS Jan 29 '19 at 15:06

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