GeoJSON Viewer
Paste GeoJSON or upload a .geojson/.json file to validate it and see it drawn on an auto-fit map preview, alongside a feature count, the geometry types present, a properties table, and a formatted view of the raw structure. Works with a Feature, a FeatureCollection, or a bare Geometry. Everything runs client-side, so nothing leaves your machine.
Reviewed by Vincenzo Manto, Founder & Lead Developer · Last updated September 27, 2026
How it works
- 1
Paste GeoJSON text or upload a .geojson/.json file.
- 2
The tool validates that it's a well-formed Feature, FeatureCollection, or Geometry.
- 3
Every shape is drawn onto an auto-fit map preview, scaled to the data's bounding box.
- 4
Review the feature count, geometry types, and a properties table, or expand the formatted GeoJSON to copy or download it.
A quick way to sanity-check GeoJSON
Whether you're debugging an API response, reviewing an export from a GIS tool, or checking a hand-written GeoJSON snippet, it helps to see it drawn out and validated before wiring it into a real map. This viewer does that without pulling in a full mapping library.
Auto-fit map preview
The preview computes the bounding box across every coordinate in your GeoJSON and scales all shapes to fit the viewport, using a simple equirectangular projection. That's enough to confirm the shapes and their relative layout are correct.
Clear validation errors
Rather than a cryptic parser failure, this tool reports specifically what's wrong: invalid JSON, a missing `features` array, or an unrecognized geometry type. That makes it easier to fix malformed GeoJSON instead of guessing.
Frequently asked questions
What GeoJSON shapes can I paste in?
A full FeatureCollection, a single Feature, or a bare Geometry object (Point, LineString, Polygon, their Multi- variants, and GeometryCollection). All of these are recognized and normalized for the preview.
How does it check whether my GeoJSON is valid?
It verifies the JSON parses, that the top-level `type` is a recognized GeoJSON type, that a FeatureCollection has a `features` array, and that every feature's geometry has a valid `type`. Clear error messages point to what's wrong.
Does it render real map tiles?
No. This is a lightweight structural preview, not a full interactive slippy map. Shapes are drawn on a blank canvas using a simple auto-fit projection, which is enough to confirm the geometry looks right.
How many features does the properties table show?
The first 20 features by default, since GeoJSON files can contain very large datasets. The map preview itself still draws every feature.
Is my GeoJSON uploaded anywhere?
No. Validation and rendering happen in your browser with plain JavaScript, and your data never leaves your device.