FAQ: What is the Difference between Add Spatial Join and Spatial Join in ArcGIS Pro?

Answer

While both tools share many similarities in terms of general function and configuration parameters, there are a few significant differences including additional parameters and output methods.

In ArcGIS Pro, both the Add Spatial Join and Spatial Join tools join attributes from one feature to another based on a spatial relationship. While both tools can be found in the geoprocessing toolbox on the Analysis tab of ArcGIS Pro, the Add Spatial Join tool can also be accessed by clicking the Data tab of the feature layer, and in the Relationship group by clicking Add Spatial Join.

Note:
Alternatively, the Add Spatial Join tool can also be accessed by right-clicking the feature layer and clicking Joins and Relates > Add Spatial Join.

The Contents pane in the map view of ArcGIS Pro.

Add Spatial Join	Properties	Spatial Join
Strictly set to a one-to-one relationship.	Relationship selection	The Join Operation parameter allows the selection of the type of spatial relationship to join the feature attributes with. By clicking the drop-down menu, the selection between a one-to-one relationship or a one-to-many relationship becomes available.
This join is temporary, so the joint attributes are merged in the attribute table of the target features.	Output location	The Spatial Join tool also has an additional Output Feature Class parameter for more control over the output location. This parameter allows the creation of a new feature class because of the spatial join.
This tool is used for the convenience of making a quick analysis of data without configuring specific customizations of the spatial join.	Usage	Provides more flexibility, allowing more customization options as well as outputting permanent data for continual analysis.

The Add Spatial Join tool provides a simple and user-friendly interface to create a temporary spatial join. The images below display the Add Spatial Join pane with the available parameters and configurations, followed by the attribute table of the target feature, Feature 1, with the attributes merged from the joint attributes, Feature 2.

The Add Spatial Join pane in ArcGIS Pro.

The Spatial Join tool provides more advanced configuration settings compared to the Add Spatial Join tool. This tool includes additional parameters such as the Output Feature Class parameter and the Join Operation parameter. The image below displays the Spatial Join pane with the available parameters and configurations, and the attribute table of the resulting spatial join in the Feature1_SpatialJoin feature class.