Question 1

What is a .topojson file?

Accepted Answer

TopoJSON stores topology-aware geographic shapes in JSON, often smaller than plain GeoJSON.

Question 2

Can OpenOnPhone preview .topojson files on phone?

Accepted Answer

Yes. OpenOnPhone can preview .topojson files locally in your browser today.

Question 3

What should I try next for .topojson files?

Accepted Answer

Choose the TOPOJSON file on the home page. OpenOnPhone shows a local geometry and coordinate summary. Use a GIS tool when you need map rendering, projection conversion, or editing.

Open TOPOJSON on Phone

Next steps