GeoDjango GeoJSON CRS Field Issue

Based on the information available in Django 5.1 documentation, the issue you're experiencing with the CRS member in GeoJSON output is valid. The current GeoJSON specification indeed discourages the use of the CRS member that Django's GeoJSON serializer includes by default.

Current Situation

Looking at the Django GIS changes over time, we can see that Django has been working to modernize its GIS components. For example, in Django 1.10:

• Support for older versions of SpatiaLite and GEOS was dropped
• The default GEOSGeometry representation (WKT output) was trimmed for cleaner output
• Several GIS-related methods were deprecated in favor of properties (like get_srid() → srid property)

However, there doesn't appear to be a documented option in Django 5.1 to disable the CRS member in GeoJSON output.

Possible Solutions

Since there's no built-in option to disable the CRS field in the serializer, you have a few options:

1. Post-process the GeoJSON: Remove the CRS member after serialization

   PYTHONCopied
   import json
   
   # Serialize to GeoJSON
   geojson_str = serializers.serialize("geojson", queryset, geometry_field="location", fields=[])
   
   # Parse, remove CRS, and re-stringify
   geojson_dict = json.loads(geojson_str)
   if "crs" in geojson_dict:
       del geojson_dict["crs"]
   clean_geojson = json.dumps(geojson_dict)

2. Create a custom GeoJSON serializer: Extend Django's GeoJSON serializer to omit the CRS field

3. File a feature request: Since this is related to compliance with current GeoJSON specifications, it would be reasonable to request an option to disable the CRS field in Django's GeoJSON serializer

Recommendation

The most appropriate approach would be to file a feature request with the Django project to add an option to disable the CRS field in the GeoJSON serializer. This aligns with Django's history of deprecating outdated GIS features in favor of more modern approaches.

In the meantime, post-processing the GeoJSON to remove the CRS member is a practical workaround that should resolve your issue with Leaflet.