About GeoJSON Viewer
Open a .geojson file in a text editor and you get a wall
of brackets and coordinate pairs — useless for confirming whether the
feature you exported from QGIS actually covers the right block, or
whether a colleague's polygon set has the right winding order, or
whether the API endpoint you just hit returned reasonable geometry.
The official path is to install QGIS or open Mapbox Studio, both of
which are full GIS environments — overkill when the question is just
"does this render?".
This GeoJSON viewer drops a file or pasted blob onto an interactive Leaflet map with OpenStreetMap tiles — no API key, no account, no upload. Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon and GeometryCollection all render with sensible default styling. The map auto-zooms to the bounding box of the feature collection so you don't have to pan to find your data. Click any feature to see its properties in a popup, or open the properties table below the map for a sortable, filterable view across all features. Geometry-type pills at the top give you a quick breakdown: '472 Polygon, 13 MultiPolygon, 8 LineString'. Everything — parsing, rendering, property inspection — runs as JavaScript in the page, so confidential boundaries, internal datasets, or anything you wouldn't paste into a public API stay on your machine.
Use it to sanity-check an export from QGIS, ArcGIS or PostGIS before shipping it to a teammate, debug a coordinate-order bug (lon-lat vs lat-lon is the classic), preview the output of a tippecanoe or ogr2ogr pipeline, audit a property set across hundreds of features, or share a quick render with someone who doesn't have a GIS desktop. Files up to roughly 10 MB or 20 k features render smoothly; for larger datasets, downstream tools like QGIS or vector tiles are the right answer.