Turn FlatGeobuf datasets into a GeoJSON file ready for web maps and APIs. Free, private and processed right in your browser.
Three steps, no software to install. Works on Windows, macOS, Linux and mobile.
01
Drop a .fgb file into the converter, or click to browse. Files up to 100 MB are supported.
02
Click Convert to GeoJSON. The file is processed locally, so your data is never uploaded to a server.
03
The GeoJSON file downloads straight to your device. Need another format? Pick a converter below.
Converted your FlatGeobuf file? Upload it to GISCARTA and turn it into an interactive map your team or clients can actually use.
Colour by attribute, cluster thousands of points, switch on 3D.
Charts and key numbers next to the map, updated as you filter.
Animate dated features and compare how places change.
Publish a read-only map, embed it on your site, or keep it private with role-based access.
No credit card. No GIS degree. Upload your data and start mapping in minutes.
FlatGeobuf is built for large datasets and cloud-native web maps. GeoJSON is built for web maps, APIs and JavaScript apps.
FlatGeobuf
FlatGeobuf is an open, binary vector format built on FlatBuffers. It stores features with a built-in spatial index, so software can read just the area it needs.
It is one of the fastest formats to read and write, and it can be streamed over HTTP from cloud storage without a map server.
GeoJSON
GeoJSON is an open standard (RFC 7946) for describing geographic features in JSON. Each feature pairs a geometry — point, line or polygon — with a set of properties.
It is the native format of web mapping libraries like Leaflet, Mapbox GL and OpenLayers, and of most geospatial APIs. The trade-off: plain text gets heavy for large datasets.
Your FlatGeobuf file
A FlatGeobuf file holds one layer.
The GeoJSON output
GeoJSON expects WGS84 longitude/latitude, so coordinates are written in that system for maximum compatibility.
Your file never leaves your device: conversion runs in your browser, for files up to 100 MB.
Load FlatGeobuf data straight into Leaflet, Mapbox GL or OpenLayers — no server-side GIS needed.
Pass FlatGeobuf features to front-end code and REST APIs in the format developers expect.
Keep the converted FlatGeobuf data as readable text that GitHub previews and diffs line by line.
Every converter runs in your browser and keeps your files on your device.
