turf.center

What is turf.center?

turf.center returns a Point at the midpoint of the bounding box of any GeoJSON Feature, FeatureCollection, or Geometry. Unlike turf.centroid (which averages vertices) or turf.centerOfMass (which uses polygon area), this function is a simple extent midpoint — fast, deterministic, and unaffected by vertex density.

turf.center(geojson, options?) → Feature<Point>

Options include:

• properties — object assigned to the output point's properties
• bbox — optional pre-computed bbox
• id — output feature id

When would you use turf.center?

Use turf.center when you need a label anchor or a map "fly to" target and you care only about geometric extent, not mass distribution. For instance, placing a country name on a choropleth, picking a zoom target for a user-drawn selection, or anchoring a popup over a FeatureCollection.

Because it is based on the bounding box, turf.center is predictable and fast even for large collections — good for Node.js services that precompute label positions or for client-side map interactions where you want consistent behaviour regardless of how densely the geometry is digitised.

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FAQs

How is turf.center different from turf.centroid and turf.centerOfMass?

turf.center is the midpoint of the bounding box — ignores vertex distribution and shape. turf.centroid is the mean of all vertices — biased by vertex density. turf.centerOfMass is the true polygon centroid weighted by area — most accurate for labelling but slower.

Will the center always fall inside the shape?

No. For concave shapes like a crescent, the bbox midpoint can fall outside the feature. If you need a point guaranteed to lie on the feature, use turf.pointOnFeature.

How do I install just turf.center?

npm install @turf/center. The package is tiny and depends only on @turf/helpers and @turf/bbox, so it plays well with tree-shaking in Vite or Webpack.

Can I attach custom properties to the output?

Yes. Pass { properties: { … } } as the second argument. This is especially useful when generating label points — you can carry the source feature's name or id straight onto the center point for rendering in a MapLibre symbol layer.