Online FlatGeobuf viewer
MapGeoData opens FlatGeobuf (.fgb) files straight in your browser. Drag one in and the map draws in seconds. It reads the format's typed columns and its coordinate system, and exports back out to GeoJSON, a shapefile, or CSV.
What FlatGeobuf is for
FlatGeobuf solves a specific problem: GeoJSON is easy to produce and slow to read. A 50MB GeoJSON has to be parsed character by character before anything can be drawn, and every coordinate starts life as text.
FlatGeobuf keeps the same information as binary, in a layout a reader can use directly, with a packed Hilbert R-tree so features that sit near each other on the map also sit near each other in the file. The result is a file that opens quickly and can be read in pieces.
It is a good working format and a poor sharing format, in the sense that whoever you send it to needs something that reads it. This page is one of those things.
Opening one
Drag the .fgb onto the map, or use the Add menu. The header carries the geometry type, the column names and their types, and the coordinate system, so the layer arrives fully described: numeric columns are ready to color by, text columns are ready to categorize by, and a projected file is reprojected to lat/long on the way in.
Converting to and from it
MapGeoData reads and writes FlatGeobuf, so it works in both directions:
- To .fgb, when you have a GeoJSON or shapefile you keep reopening. Export as FlatGeobuf once and every later load is faster.
- From .fgb, when you need to hand the data to something that doesn't read it. Export as GeoJSON, a Shapefile ZIP, or CSV.
Both directions run in your browser, so nothing is uploaded to convert.
What you can do once it's open
- Style by column, with ramps, categories, classed choropleths, sizing, and labels.
- Filter to a value range, or select by expression.
- Inspect any feature, or open the full data table to sort, filter, and edit.
- Analyze: measure, buffer, dissolve, spatial join, clip, or summarize by field.
- Export to any of the supported formats.
Runs in your browser
The file is read and drawn by code running in your browser, so it never leaves your machine. There's nothing to install and no account to create. It sets no tracking cookies, and we never sell or share your data.