GeoJSON Viewer

Paste a GeoJSON object, or load a .geojson file, and see it two ways at once: every geometry drawn on a lightweight map, and a list of features with their properties laid out as readable chips. Points, lines, polygons, and their multi- and collection variants are all supported, and the bounding box is reported so you know exactly where the data sits. The preview uses a local projection and draws no map tiles, so nothing is uploaded — coordinates from a survey, an export, or an API response stay on your machine.

How to use the GeoJSON Viewer

Paste GeoJSON into the box or load a .geojson or .json file. The viewer parses the text, validates that it is JSON, and then reads the GeoJSON structure. It accepts a FeatureCollection, a single Feature, a GeometryCollection, or a bare geometry object such as a Point or Polygon, so you can drop in a whole export or just one shape you copied from an API response.

Above the list, every geometry is drawn onto a compact map. Points appear as dots, lines as strokes, and polygons as filled outlines, all fitted to the data's bounding box so the shape fills the frame no matter where on Earth it sits. The map is generated entirely from your coordinates with a local projection, so no map-tile images are requested from any server. Below the map, each feature is shown with its geometry type and its properties rendered as key and value chips, which makes it easy to confirm that the right attributes are attached to the right shapes.

The status line summarises what was found: the number of features, a count of each geometry type, the total number of coordinates, and the longitude and latitude bounds. If the text is not valid JSON, the parser's message is shown with the position of the fault so you can fix a stray comma or unquoted key. If the JSON is valid but contains no recognisable GeoJSON geometry, the viewer says so rather than drawing an empty frame.

What GeoJSON is and how it is structured

GeoJSON is a JSON-based format for encoding geographic data, standardised as RFC 7946. Because it is ordinary JSON, it can be produced, parsed, and stored by any tool that already speaks JSON, which is a large part of why it became the lingua franca for passing map data between web services, mapping libraries, and GIS tools.

The format defines a small set of geometry types. A Point is a single position, a LineString is an ordered list of positions, and a Polygon is one or more closed rings where the first ring is the outer boundary and any further rings are holes. Each of these has a "multi" variant — MultiPoint, MultiLineString, and MultiPolygon — for grouping several shapes into one geometry, and a GeometryCollection can hold a mixture of types. Every position is an array written as [longitude, latitude], and that order trips people up constantly, because most of us say "latitude, longitude" out loud. An optional third number carries elevation.

Geometry on its own is rarely enough, so GeoJSON wraps it. A Feature pairs one geometry with a free-form properties object holding attributes such as a name, a category, or a population figure, and an optional id. A FeatureCollection is simply an array of features, and it is the form most exports take. The specification fixes the coordinate reference system to WGS 84 — the same datum GPS uses — so a GeoJSON file from one source lines up with another without reprojection. It also recommends that coordinates be written longitude-first and that rings follow the right-hand rule, though many real-world files bend those rules, which is why a viewer that simply draws what is there is useful for spotting reversed or out-of-range coordinates at a glance.

Common use cases

  • Sanity-checking an export. Confirm that a GeoJSON file from a GIS tool or database query contains the shapes and attributes you expect before loading it into a map.
  • Debugging an API response. Paste a geometry returned by a geocoding or routing API and see where it actually lands.
  • Spotting flipped coordinates. If a shape appears in the wrong place or mirrored, the lon/lat order or sign is usually the culprit, and the map makes that obvious.
  • Reading properties. Browse the attributes attached to each feature without scrolling through raw nested JSON.

Frequently asked questions

What GeoJSON types can it draw?
All of them: Point, LineString, Polygon, their Multi variants, GeometryCollection, plus Feature and FeatureCollection wrappers. A bare geometry object works too, so you can paste just one shape.

Does it download map tiles or call a server?
No. The preview is drawn purely from your coordinates with a local projection. No basemap tiles are fetched and nothing is uploaded, so the data stays entirely in your browser.

Why does my shape look like it is in the wrong place?
GeoJSON positions are written longitude first, then latitude. If coordinates are swapped or have the wrong sign, shapes land in the wrong hemisphere. Seeing them drawn is the fastest way to catch that.

Is there a basemap with countries or streets?
No, by design. The viewer draws only your geometry against a plain background so it works offline and reveals nothing to a tile server. It is built for inspecting the data, not for cartography.

Is my data uploaded anywhere?
No. Parsing and rendering happen entirely in your browser with the built-in JSON parser and inline SVG. Coordinates and properties never leave your device.