Is it possible to word wrap the field alias text in a pop-up in ArcGIS Online?

Answer

No, it is not possible to word wrap the field alias text in a pop-up in ArcGIS Online. As a workaround, open the hosted feature layer in ArcGIS Pro, configure the pop-up, and overwrite the hosted feature layer to ArcGIS Online.

1. Log in to ArcGIS Pro using ArcGIS Online login credentials and open the Catalog pane. Refer to ArcGIS Pro: Open the Catalog pane for instructions.
2. In the Catalog pane, click the Portal tab and navigate to the hosted feature layer.
3. Drag the hosted feature layer to the map.
4. Configure the pop-ups to word wrap the field alias text in ArcGIS Pro. Refer to How To: Stack the field name in a pop-up in ArcGIS Pro for instructions.

The image below shows the field alias 'Bench Length In Inches' appears wrapped in ArcGIS Online Map Viewer.