# GeoJSONFeatureId

> **GeoJSONFeatureId** = `number` | `string`

Defined in: [source/geojson\_source\_diff.ts:4](<https://github.com/maplibre/maplibre-gl-js/blob/538a7680ab16d5cf5a6564ee0ce72a11be14d142/src/source/geojson_source_diff.ts#L4>)

A way to identify a feature, either by string or by number