Paste GeoJSON or open a .geojson file to see its points, lines and polygons on a map. Click a feature to read its properties, edit values in the table or the code editor, add points, fix common coordinate mistakes and download the result. Nothing is uploaded.
Last updated:
Click on the map to add a point · Esc to stop
Basemap tiles could not be loaded (offline or blocked), but your features are drawn on a plain grid.
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How to use the GeoJSON Viewer
Load your data: press Open GeoJSON, drop a file onto the map, paste GeoJSON anywhere on the page, or type it in the GeoJSON tab. A San Francisco sample loads first.
Explore the map: drag to pan, scroll or pinch to zoom, and click a feature to see its properties.
Edit: change values in the Features table, add a property column, delete features, or press Add point and click the map.
Validate: open the Validation tab to see errors and warnings with their JSON path; click one to jump to the feature, or use the suggested fix.
Export: download the edited data as .geojson or CSV (WKT), or copy it.
GeoJSON geometry types at a glance
Type
coordinates shape
Example
Rules (RFC 7946)
Point
position
[-122.4058, 37.8024]
[longitude, latitude], optional altitude in metres
MultiPoint
array of positions
[[-122.41, 37.80], [-122.39, 37.79]]
Any number of positions
LineString
array of positions
[[-122.39, 37.79], [-122.41, 37.80]]
At least 2 positions
MultiLineString
array of LineString arrays
[[[…], […]], [[…], […]]]
Each line needs 2+ positions
Polygon
array of linear rings
[[[0,0],[1,0],[1,1],[0,1],[0,0]]]
Rings have 4+ positions, first = last; exterior counterclockwise, holes clockwise
MultiPolygon
array of Polygon arrays
[[[[…]]], [[[…]]]]
Same ring rules for every polygon
GeometryCollection
"geometries" array instead
{"type":"GeometryCollection","geometries":[…]}
Should not be nested
Common GeoJSON mistakes and how to spot them
Latitude and longitude swapped. Many APIs and spreadsheets list latitude first, but GeoJSON is longitude first. Points in the US will have a negative first number (west) and a positive second number around 25 to 49.
Projected coordinates. Values like -13627361, 4544761 are Web Mercator metres (EPSG:3857). Re-export as EPSG:4326 / WGS 84, or use the conversion button in the Validation tab.
Open polygon rings. The last position of each ring must repeat the first one exactly.
Too many decimals. Six decimal places is about 0.1 m of precision, which is more than enough for most data; extra digits only make files bigger.
The old crs member. The 2008 GeoJSON spec allowed other coordinate systems; RFC 7946 removed it, and most software now assumes WGS 84.
Feature styling follows the widely used simplestyle convention: set stroke, stroke-width, fill, fill-opacity or marker-color in a feature's properties to change how it is drawn here and on GitHub.
Frequently asked questions
What is GeoJSON?
GeoJSON is a JSON format for geographic data, standardized in RFC 7946 (2016). A file is usually a FeatureCollection whose features each have a geometry (Point, LineString, Polygon or their Multi versions) and a properties object with attributes such as a name or population. It is the default exchange format for web maps, Leaflet, Mapbox, GitHub and many GIS tools.
Why are my features in the wrong place or missing?
GeoJSON coordinates must be [longitude, latitude] in WGS 84 decimal degrees. The most common mistakes are writing [latitude, longitude] (features land in the wrong hemisphere or fail validation) and exporting projected coordinates in metres, such as Web Mercator EPSG:3857. The Validation tab detects both and offers a one-click conversion.
What does the right-hand rule warning mean?
RFC 7946 says a polygon's exterior ring should run counterclockwise and holes clockwise. Many tools ignore winding order, but some renderers and databases use it to decide what is inside the polygon. It is a warning rather than an error, and the Fix ring order button rewinds every ring for you.
Is my data uploaded anywhere?
No. Your GeoJSON is parsed and validated by JavaScript in your browser. Only the background map tiles are requested from the OpenStreetMap tile server, which receives the map area being viewed, not your features. You can switch the basemap off to stop all tile requests.
How big a GeoJSON file can it handle?
Files of tens of megabytes with thousands of features work well because geometry is projected once and simplified to screen pixels while drawing. Very large files (over about 5 MB) open in read-and-table mode without the text editor, and for hundreds of megabytes you should simplify the data first, for example with mapshaper.
Does it support TopoJSON, KML or Shapefiles?
No, this viewer reads GeoJSON (including newline-delimited GeoJSON). Convert other formats to GeoJSON first; GPS tracks in GPX format can be opened in the GPX Viewer, which shows distance, elevation and speed.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.