A modular geospatial engine written in JavaScript

turfjs.org

---

Turf is a JavaScript library for spatial analysis. It includes traditional spatial operations, helper functions for creating GeoJSON data, and data classification and statistics tools. Turf can be added to your website as a client-side plugin, or you can run Turf server-side with Node.js (see below).

Installation

In Node.js

# get all of turf
npm install @turf/turf

# or get individual packages
npm install @turf/helpers
npm install @turf/buffer

In browser

Download the minified file, and include it in a script tag. This will expose a global variable named turf.

<script src="turf.min.js" charset="utf-8"></script>

You can also include it directly from a CDN:

<script src="https://cdn.jsdelivr.net/npm/@turf/turf@6/turf.min.js"></script>

TypeScript

Turf modules ship with type definitions packaged in each module. No DefinitelyTyped packages required.

The types defined in the GeoJSON specification are maintained separately (Geometry, Polygon, etc). To refer to these in your own code, install @types/geojson and import from there:

import { type Polygon } from "geojson";

Other languages

Ports of Turf.js are available in:

• Java (Android, Java SE)

  • The current to-do list for porting to Java

• Swift (iOS, macOS, tvOS, watchOS, Linux)

  • Turf for Swift is experimental and its public API is subject to change. Please use with care.

• Dart/Flutter (Dart Web, Dart Native; Flutter for iOS, Android, macOS, Windows, Linux, Web)

  • The Turf for Dart port is still in progress, the implementation status can be found in the README.

---

Data in Turf

Turf uses GeoJSON for all geographic data. Turf expects the data to be standard WGS84 longitude, latitude coordinates. Check out geojson.io for a tool to easily create this data.

NOTE: Turf expects data in (longitude, latitude) order per the GeoJSON standard.

Most Turf functions work with GeoJSON features. These are pieces of data that represent a collection of properties (ie: population, elevation, zipcode, etc.) along with a geometry. GeoJSON has several geometry types such as:

• Point
• LineString
• Polygon

Turf provides a few geometry functions of its own. These are nothing more than simple (and optional) wrappers that output plain old GeoJSON. For example, these two methods of creating a point are functionally equivalent:

// Note order: longitude, latitude.
var point1 = turf.point([-73.988214, 40.749128]);

var point2 = {
  type: 'Feature',
  geometry: {
    type: 'Point',
    // Note order: longitude, latitude.
    coordinates: [-73.988214, 40.749128]
  },
  properties: {}
};

Browser support

Turf packages are compiled to target ES2017. However, the browser version of @turf/turf is transpiled to also include support for IE11. If you are using these packages and need to target IE11, please transpile the following packages as part of your build:

@turf/*
robust-predicates
rbush
tinyqueue

Contributors

This project exists thanks to all the people who contribute. If you are interested in helping, check out the Contributing Guide.

Backers

Thank you to all our backers! 🙏 [Become a backer]

Sponsors

Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]