Is it possible to split a line or polygon feature in ArcGIS Online?

Answer

It is not possible to split a line or polygon feature in ArcGIS Online Map Viewer. However, it is possible to do so using ArcGIS Web AppBuilder in ArcGIS Online, and the result is reflected at the web map level in Map Viewer. The following steps describe how to split polygon features and line features in ArcGIS Web AppBuilder.

Note:
The following workflow is only applicable to web maps with editable hosted feature layers. Refer to ArcGIS Online: Manage editor settings for more information.

1. In ArcGIS Online, navigate to Content > My Content.
2. Browse to the desired web map, click the More Options button, and select Open in Map Viewer.
3. In Map Viewer, click Save > Save to save the web map.
4. Click Share, and create the ArcGIS Web AppBuilder app. Refer to ArcGIS Web AppBuilder: Create your first app for more information.
5. In ArcGIS Web AppBuilder, click the Widget tab, and click Set the widgets in this controller.
6. Click the Click here to add widget button to add a new widget in the top panel.

Note:
Alternatively, on the Widget tab, scroll to and click Widget 1, 2, 3, 4 or 5 to add a new widget.

7. In the Choose Widget window, select the Edit widget, and click OK.

8. In the Configure Edit window, under General settings, check the Cut check box, and click OK.

9. In the top panel, click the Edit button.
10. In the Edit window, click the Cut tool, and split the desired line or polygon feature.
11. Save the app.

The images below show the cut line and polygon features in ArcGIS Web AppBuilder, with the result reflected at the web map level in ArcGIS Online Map Viewer.

In ArcGIS Web AppBuilder:

In ArcGIS Online Map Viewer: