Add points by clicking the map or uploading a CSV or zipped Shapefile, then draw or upload a boundary polygon. One click runs the spatial join, colouring every point green (inside) or grey (outside) and giving you a live count of each — then download the inside points, the outside points, or both, as GeoJSON or CSV. Open in full screen ↗
What Is a Points-in-Polygon Spatial Join?
A points-in-polygon test — also called a spatial join — answers one question for every point in a dataset: does it fall inside a given boundary shape, or outside it? It sounds simple, but doing it by eye against a list of coordinates is slow and error-prone once you have more than a handful of points. This tool automates the whole test in your browser: load any number of points, draw or upload the boundary you care about, and get an instant, exact inside/outside classification for every single one, ready to export.
Watch: Points in Polygon Tool in Under a Minute
Prefer to watch instead of read? This short walkthrough covers adding a boundary polygon, adding points, and finding which ones fall inside.
Common Questions
How many points can I check at once?
Up to 3,000 points per run. If an uploaded file has more, the first 3,000 are loaded and you're told how many were left out.
Is my data uploaded to a server?
No. Reading your files, running the spatial join, and generating the export files all happen locally in your browser using Turf.js. Nothing is sent to or stored on a server, so it's safe to use with private location data.
What file formats can I upload for the boundary?
A zipped Shapefile (.zip) or a .geojson file containing Polygon or MultiPolygon features, or you can draw the boundary directly on the map by clicking its corners.
What happens to a point sitting exactly on the boundary line?
It's counted as inside. The underlying point-in-polygon test treats the boundary line itself as part of the polygon.
Can I use more than one boundary polygon at a time?
Yes. Draw or upload as many boundary polygons as you like — a point is marked "inside" as soon as it falls within any one of them, and is tagged with the name of the polygon it matched.
Can I export just the points that fell outside the boundary?
Yes — the Export section has a dedicated "Outside Points (GeoJSON)" download alongside the inside-points GeoJSON and CSV downloads.
Does the tool work with MultiPolygon boundaries, like a country made of several islands?
Yes. Uploaded MultiPolygon features are treated as a single boundary — a point inside any part of it is marked inside.
What file formats can I upload for points?
A CSV file with latitude and longitude columns, or a zipped Shapefile (.zip) containing point features. Common column names such as lat/lng, latitude/longitude, or y/x are detected automatically; if they can't be, you're asked to pick the right columns from a dropdown.
How the Inside/Outside Test Works
Once you click "Match Points Inside Boundary", every point is tested against every polygon in your boundary layer using Turf.js's exact point-in-polygon algorithm — the same well-tested approach used across professional GIS software. If your boundary layer has more than one polygon (for example several separate zones drawn or uploaded together), a point counts as "inside" the moment it matches any one of them, and is tagged with the name of the polygon it matched. A point sitting exactly on a boundary line is counted as inside. The test runs entirely in your browser, so results appear in well under a second even for thousands of points.
Exporting Your Results
After running the spatial join, the sidebar's Export section offers three downloads, each reflecting the colours and counts shown on the map:
- Inside Points (GeoJSON): every point classified as inside the boundary, with a pip_status and pip_boundary property added, plus any original attributes from your upload kept intact.
- Inside Points (CSV): the same inside points as a spreadsheet-ready CSV file, with latitude and longitude as the first two columns.
- Outside Points (GeoJSON): every point that fell outside every polygon in your boundary layer, in the same tagged GeoJSON format.
All three files open directly in QGIS, ArcGIS, Excel, Google Sheets, or any tool that reads standard GeoJSON or CSV — no conversion step required.
Real-World Use Cases
🛰️
Asset & Fleet Tracking
Operations teams verify which GPS-tracked vehicles or assets are currently inside an approved service or geofence area.
🚨
Emergency Response Coverage
Responders and planners identify which reported incident locations fall inside a specific jurisdiction or response-zone boundary.
🏘️
Real Estate Filtering
Agents and analysts filter a list of property coordinates down to only those inside a specific neighbourhood, school catchment, or flood zone boundary.
🗳️
Electoral & District Analysis
Researchers test which addresses or survey responses fall inside a voting precinct or administrative district boundary.
📦
Store & Warehouse Coverage
Retail and logistics analysts confirm which store or warehouse locations fall inside a defined regional coverage area.
🚚
Delivery Zone Assignment
Logistics teams check which customer addresses fall inside a delivery or service zone boundary before routing orders.
🏫
School Catchment Analysis
Education planners check which student home addresses fall inside a school's official catchment boundary.
🌾
Agriculture & Field Sampling
Agronomists check which soil sample or sensor points fall inside a specific field boundary before analysing the results.
Step by Step
1Step 1
Open the tool
The map opens on a world view with no data yet. The sidebar has separate Points and Boundary sections, a Run button, and an Export section that unlocks once you have a result.
2Step 2
Add your points
Click "+ Add on Map" and click the map to place points by hand, or upload a CSV or zipped Shapefile of points from the Points section.
3Step 3
Add your boundary
Click "✏ Draw on Map" and click each corner of your boundary, finishing with "✓ Finish Boundary", or upload a zipped Shapefile or GeoJSON file from the Boundary section.
4Step 4
Try Load Demo Data instead
If you just want to see how it works first, click "Load Demo Data" to instantly populate a sample boundary and a mix of inside and outside points.
5Step 5
Run the spatial join
Click "Match Points Inside Boundary". Every point on the map recolours to show its result, and the sidebar shows the inside and outside counts.
6Step 6
Export your results
Use the Export section to download the inside points, the outside points, or both, as GeoJSON or CSV.
Two Ways to Add Points and Boundaries
Points and the boundary polygon are added independently, and each supports both a manual and a file-based method:
- Click to add points: toggle "+ Add on Map" in the sidebar, then click anywhere on the map to drop a point. Click the toggle again, or press Esc, to stop.
- Upload points (CSV or Shapefile): upload a CSV with latitude/longitude columns — common column names like lat/lng, latitude/longitude or y/x are detected automatically, with a manual picker if they aren't — or a zipped Shapefile of point features.
- Draw the boundary: click "✏ Draw on Map", then click each corner of your boundary polygon on the map. Click "✓ Finish Boundary" once you have at least three points to close the shape.
- Upload the boundary: upload a zipped Shapefile or a .geojson file containing one or more Polygon or MultiPolygon features. The map zooms to fit the boundary automatically.
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Map tiles © OpenStreetMap contributors, drawn with Protomaps (hosted by KONAKTIVE), with CARTO as the fallback. Satellite imagery: Esri. Geometry calculations: Turf.js. Shapefile reading: shpjs. Map rendering: Leaflet. All calculations run in your browser, and nothing you enter is stored on a server.
