Can a field name be changed in the ArcGIS Enterprise portal or ArcGIS Online?

No, it is not possible to change a field name in the ArcGIS Enterprise portal or ArcGIS Online. Once a field name is set and saved in its source layer, it cannot be changed. However, the display name of the field can be changed in the ArcGIS Enterprise portal or ArcGIS Online. A display name is the field name displayed on the hosted feature layer's attribute table. Refer to ArcGIS Online: Set a display name or ArcGIS Enterprise on Windows and Linux: Set a display name for more information and instructions to change a field's display name.

Alternatively, if a new name is required to ensure data precision, add a new field and copy the field values from the intended field to the new field by following the steps provided below.

1. Log in to the ArcGIS Enterprise portal or ArcGIS Online and add a new field. Refer to ArcGIS Online: Add a field or ArcGIS Enterprise on Windows and Linux: Add a field for instructions.
2. Copy the intended field value to the newly created field.
   1. Click Menu on the header of the new field and select Calculate.
   2. For Field, click the drop-down menu to select the field.
   3. For Select language, select SQL > Next.
   4. Specify the SQL expression field as below. Replace <Field_Name> with the name of the field containing the values to be copied.

   <Field_Name>
   

   5. Click Run calculation to apply the query.