CSV Attribute Join
Join CSV columns onto GeoJSON features using explicit matching property names while keeping feature geometry and processing both inputs locally.
Input
Join keys are compared as exact strings and duplicate CSV keys keep the last row; review unmatched counts and renamed column conflicts.
Review these warnings
GeoJSON
Map preview
Understanding CSV Attribute Join
Records, properties and matching keys
Join CSV columns onto GeoJSON features using explicit matching property names while keeping feature geometry and processing both inputs locally.
CSV Attribute Join works with feature properties: the non-spatial fields attached to each geometry. Consistent field names, value types and stable identifiers make attribute operations more reliable.
How to review the records
Join keys are compared as exact strings and duplicate CSV keys keep the last row; review unmatched counts and renamed column conflicts.
When reviewing CSV Attribute Join, compare feature counts and a sample of properties before and after the operation. Pay particular attention to missing values, duplicate keys and values stored as different types.