Strategies for dealing with large geojson files


I’ve recently been working with a project where I want to try to load larger (50-150 MB) geojson files. For example I have one files which is about 50 MB and ~9000 isolines that I want to show. Just loading the geojson file normally crashes the browser. Obviously I could rasterize it and load it as raster tiles, but I’d rather not go that way if possible. I’ve been experimenting with turning the lines into surfaces and saving them as cesium tilesets which kind of works and has good enough performance but adds an extra step in the process and is a lot less flexible.

Basically I’d be interested to see what thoughts and approaches other people have to this question. Are there any things I haven’t considered or optimizations I could look into or does Cesium have any plans or ideas on its road map from handling large sets of vector data.



Hey Dag,

This has been a known problem for a while. I believe this pull request resolves this issue:

But was put on hold because there were some potential incompatibilities it would introduce with other engines using Cesium. I’ve been curious if this PR really does fix it, so it might be worth trying out and posting here/in the PR what your results were.

I believe the current strategy is to develop the 3D Tiles vector format ( so that data like GeoJSON/KML can be converted to it and be streamable, we just haven’t gotten around to developing the tooling for that yet.

The other thing to try, I haven’t actually tested this but I think it’ll work because the issue isn’t from the total size of the file but from how Cesium loads it, is breaking it up into a series of small GeoJSON files that you could load one by one.

Hi Omar,

Is there any update on this issue.I’m facing the same issue.Unable to load large json files,browser crashes.What could be your suggestion for this.I want load only in json format(not as tileset).

What is the threshold limit for the size of json.

How big are your JSON files? Are you able to share an example of one that causes a crash?

I have the same problem. Here is my geojson file

Sorry for the late reply ,
My json files are around 60 to 200mb.

Sorry i cannot share the files.

Is there any way deal with these errors?

Yeah I think tiling these GeoJSONs into a 3D Tiles Vector format would be the right way to be able to handle these large geometries. The 3D Tiles Vector format is currently still a work in progress though. See the roadmap issue here: