Uniformly random coordinates land in the ocean roughly seventy per cent of the time, which makes for a strange-looking map. The land mode clusters points near real cities, so pins fall where a reviewer expects to see them.
What you can control
- Land mode scatters points within a few kilometres of real populated places.
- Custom bounding boxes take
minLng,minLat,maxLng,maxLat, the same order GeoJSON uses. - Four output formats, including GeoJSON points ready to drop into a
FeatureCollection. - Precision is adjustable from one to eight decimal places — six is about a metre.
What this is not
GeoJSON puts longitude before latitude, and almost every other format does the opposite. That reversal is the most common bug in mapping code, so check which one your consumer expects.
Questions
Why is longitude first in GeoJSON?
The specification follows the x,y convention from mathematics rather than the lat,lng convention from navigation. It is a genuine trap and worth checking every time.
How precise is six decimal places?
About 0.11 metres at the equator. Five places gets you to roughly a metre, which is enough for almost any application.
How do I keep points on land?
Use the land mode, which anchors to real cities. A custom bounding box over open ocean will happily produce points at sea.