TopoJSON viewer
View TopoJSON files (.topojson, .json) on a 3D map in your browser. A topology-encoded extension of GeoJSON that shrinks shared boundaries. No account, no install, no upload until you decide to convert or hand off to the rooot.it route planner.
Open the viewer → or jump straight to a conversion:
About TopoJSON
TopoJSON encodes geometry as arcs that can be reused across features, so choropleths and country boundaries shrink dramatically compared to GeoJSON. It is the format of choice for D3.js choropleth maps.
How to view a TopoJSON file
- Open the viewer.
- Drag your TopoJSON file (.topojson, .json) onto the page, or click the + in the Places panel.
- The file renders on a 3D MapLibre globe. Use the right-hand panel to toggle background layers (borders, labels, roads, buildings, transportation, places, terrain).
- Click features for details, or use the bottom toolbar to convert to another format.
Convert TopoJSON to other formats
TopoJSON viewer FAQ
How do I view a TopoJSON file online?
Drop the .topojson on rooot viewer. It expands the arc topology to GeoJSON internally and renders every feature on a 3D map.
Where does TopoJSON come from?
Most often from the D3.js / Observable choropleth toolchain or mapshaper.org. It is also a common output of geo-publication pipelines.
Is rooot viewer free?
Yes. No account required. There are no per-conversion or per-view charges.
Does rooot viewer upload my files?
Files are parsed server-side for rendering but are not persisted unless you click Convert or Open in roooute. Persisted files are deleted within 24 hours.
Privacy
Files dropped on the main viewer are parsed server-side for rendering but are not persisted. Persistence happens only when you click Convert or Open in roooute; persisted files are deleted within 24 hours. Direct conversions through the per-format converter pages do not persist anything at all.