Can sketch features be included in a legend in ArcGIS Online and the Enterprise portal?

No, sketch features cannot be included in the legend in ArcGIS Online and the ArcGIS Enterprise portal. Unlike feature layers, sketch layers do not store attribute data and are intended for temporary annotations or quick visualizations on a web map. As a result, they are treated as graphics rather than data-driven layers and are not included in the legend by default. However, in some cases, displaying sketch features in the legend can improve map readability and interpretation. For example, the legend can differentiate between proposed sketches and existing features on the web map.

An alternative is to export the sketch features to a feature layer in ArcGIS Pro, publish it as a hosted feature layer and add it to the web map. Refer to the workaround below to include the sketch features in the legend in ArcGIS Online and the Enterprise portal.

1. Open the web map with the sketch features in ArcGIS Pro. Refer to ArcGIS Pro: Add a web map or web scene for instructions.
2. Export the sketch features to a feature class. Refer to ArcGIS Pro: Export data for more information.
1. In the Contents pane, right-click the sketch layer, click Data and click Export Features.
2. In the Export Features dialog box, for Output Feature Class, click Browse and specify the location and name of the output feature class.
3. Click OK.

The output feature layer is added to the Contents pane.

Note:
Optionally, before publishing the feature layer, configure the layer symbology. Refer to ArcGIS Pro: Apply symbology to feature layers for instructions.

3. Publish the feature layer to ArcGIS Online. Refer to ArcGIS Pro: Share a web feature layer using the default configuration for instructions.
4. Add the hosted feature layer to the web map. Refer to ArcGIS Online: Browse layers or ArcGIS Enterprise: Browse layers for instructions.

The web map below shows the exported sketch layer included in the legend.