Spatial Join

Join attributes from Layer B into Layer A using Intersect, Within, Contains, or Nearest (with threshold). Entirely in your browser.

No upload Joins & Aggregations Standards‑based

Tip: Choose a Relation and Join type. Use Scan Attributes to pick which fields from B to bring into A. For multiple matches per A, enable Aggregations (sum/avg/min/max/count) or pick the first match.

Relation

Join type

Precision

decimals

Applied to output coordinates.

Fields from B

If multiple matches

Aggregations (numeric fields only):

sum

avg

min

max

Also include count

Output geometry

Explode multiparts

Drop features with null geometry

Layer A (receives attributes)

Paste GeoJSON (or choose file)

Choose .geojson/.json

Layer B (provides attributes)

Paste GeoJSON (or choose file)

Choose .geojson/.json

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Result

No data yet.

Output: GeoJSON

Map Preview

Notes:

Spatial Join writes B fields into A features. For Nearest, distance is great‑circle; optionally stored as distance_m.
For Intersection geometry, result geometry is A ∩ B when a match exists; otherwise A geometry may be null (toggle drop nulls).
To improve performance, reduce feature counts and simplify geometries before joining.