How to Find Nearby Locations in MongoDB Using Geospatial Queries

To find nearby locations in MongoDB, use a 2dsphere index on your location field and query with the $near operator specifying a point and max distance. This lets MongoDB efficiently return documents ordered by proximity to the given coordinates.

Syntax

To find nearby locations, you use a geospatial query with the $near operator on a field indexed with 2dsphere. The query looks like this:

{
  locationField: {
    $near: {
      $geometry: {
        type: "Point",
        coordinates: [longitude, latitude]
      },
      $maxDistance: distanceInMeters
    }
  }
}

Here:

• locationField is the field storing GeoJSON points.
• $geometry defines the reference point.
• $maxDistance limits results to within this distance in meters.

Make sure the locationField has a 2dsphere index for this to work efficiently.

json

{
  location: {
    $near: {
      $geometry: {
        type: "Point",
        coordinates: [-73.9667, 40.78]
      },
      $maxDistance: 5000
    }
  }
}

Example

This example shows how to create a collection with location data, add a 2dsphere index, insert sample locations, and query for nearby places within 5 kilometers.

mongodb

use testdb;

// Create collection and insert sample data
db.places.insertMany([
  { name: "Central Park", location: { type: "Point", coordinates: [-73.9654, 40.7829] } },
  { name: "Times Square", location: { type: "Point", coordinates: [-73.9851, 40.7580] } },
  { name: "Empire State Building", location: { type: "Point", coordinates: [-73.9857, 40.7484] } }
]);

// Create 2dsphere index
db.places.createIndex({ location: "2dsphere" });

// Find places near a point within 5 km
const nearbyPlaces = db.places.find({
  location: {
    $near: {
      $geometry: { type: "Point", coordinates: [-73.985, 40.758] },
      $maxDistance: 5000
    }
  }
}).toArray();

printjson(nearbyPlaces);

Output

[
  {
    "_id": ObjectId("..."),
    "name": "Times Square",
    "location": { "type": "Point", "coordinates": [-73.9851, 40.758] }
  },
  {
    "_id": ObjectId("..."),
    "name": "Empire State Building",
    "location": { "type": "Point", "coordinates": [-73.9857, 40.7484] }
  },
  {
    "_id": ObjectId("..."),
    "name": "Central Park",
    "location": { "type": "Point", "coordinates": [-73.9654, 40.7829] }
  }
]

Common Pitfalls

Common mistakes when finding nearby locations in MongoDB include:

• Not creating a 2dsphere index on the location field, which makes queries slow or fail.
• Using coordinates in the wrong order; MongoDB expects longitude first, then latitude.
• Not using GeoJSON format ({ type: "Point", coordinates: [...] }) for location data.
• Setting $maxDistance in the wrong units; it must be in meters.

Example of a wrong query (no index):

db.places.find({
  location: {
    $near: {
      $geometry: { type: "Point", coordinates: [40.758, -73.985] }, // latitude and longitude reversed
      $maxDistance: 5000
    }
  }
});

Corrected query:

db.places.find({
  location: {
    $near: {
      $geometry: { type: "Point", coordinates: [-73.985, 40.758] },
      $maxDistance: 5000
    }
  }
});

Quick Reference

Concept	Description
2dsphere Index	Index type needed for GeoJSON location queries
$near	Operator to find documents near a point
$geometry	Defines the GeoJSON point for the query
$maxDistance	Limits results to within this distance in meters
Coordinates Order	Always [longitude, latitude]

Key Takeaways

Create a 2dsphere index on your location field before running geospatial queries.

Use the $near operator with $geometry and $maxDistance to find nearby locations.

Always store and query coordinates as GeoJSON Points with longitude first, then latitude.

Distances in $maxDistance are measured in meters.

Check your data format and index if queries return no results or are slow.