Is the output valid GeoJSON?

Yes. The tool emits a FeatureCollection following RFC 7946, with coordinates ordered as longitude then latitude, and polygon rings closed by repeating the first vertex at the end. It should load directly into Leaflet, Mapbox GL, or any spec-compliant viewer.

Why are coordinates longitude first?

The GeoJSON specification requires position arrays in the order longitude, latitude, which is the opposite of the common human-readable lat, lon convention. Mixing these up is the most frequent GeoJSON bug, so the tool always uses the spec order.

What is in the properties of each feature?

Every feature gets a small set of fake attributes — an id, a generated name, a category, a numeric value, and a boolean active flag — so you can test styling, popups, and filtering logic against realistic property keys.

How are polygons kept valid?

Each polygon is built as a ring of vertices arranged around the center point, and the first vertex is repeated as the last so the ring is properly closed. This satisfies the GeoJSON requirement that linear rings form a closed loop.

Does this send my data anywhere?

No. Generation runs entirely in your browser with no API calls, so you can produce as many features as you like privately and offline.

Fake GeoJSON Generator

This tool generates valid GeoJSON — a FeatureCollection of random Point, LineString, or Polygon features with fake property data — for testing mapping libraries without hand-writing fixtures. The output follows RFC 7946 exactly, including the spec’s longitude-first coordinate order and properly closed polygon rings.

How it works

GeoJSON wraps geometry in Feature objects, which are collected into a FeatureCollection. The tool builds each feature around the center point you provide:

Point — a single [lon, lat] position jittered near the center.
LineString — a chain of 2 to 5 connected positions that wander from the center.
Polygon — a ring of vertices placed around the center on a small circle, with the first vertex repeated at the end to close the ring as the spec requires.

Each feature also receives a properties object with an id, name, category, numeric value, and active flag so you can exercise popups, styling, and filtering.

Tips and notes

Always remember GeoJSON positions are [longitude, latitude] — the reverse of how people usually say coordinates aloud.
Set the center to your map’s focus area so the random features render inside the visible viewport.
Use Mixed mode to confirm your renderer handles all three geometry types in a single collection.