> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/help/ja/llms.txt)

# Turf.js

**Turf.js** is an open-source JavaScript library used for [spatial analysis](http://en.wikipedia.org/wiki/Spatial_analysis). It includes traditional spatial operations, helper functions for creating [GeoJSON](https://docs.mapbox.com/help/ja/glossary/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](https://www.npmjs.com/package/@turf/turf) with [Node.js](http://nodejs.org/). You can find the source code on [GitHub](https://github.com/turfjs/turf).

Turf works well with [Mapbox GL JS](https://docs.mapbox.com/mapbox-gl-js/). The Mapbox Java SDK also has a [Turf for Java library](https://docs.mapbox.com/android/java/overview/turf/).

**Related resources:**

-   [Turf.js documentation](http://turfjs.org)
-   Getting started: [Spatial analysis](https://docs.mapbox.com/help/ja/dive-deeper/geospatial-analysis/)
-   Tutorial: [Analyze data with Turf.js and Mapbox GL JS](https://docs.mapbox.com/help/ja/tutorials/analysis-with-turf/)
-   Example: [Measure distances with Turf.js](https://docs.mapbox.com/mapbox-gl-js/example/measure/)