A feature layer is a grouping of similar geographic features, for example, buildings, parcels, cities, roads, and earthquake epicenters. Features can be points, lines, or polygons (areas). Feature layers are most appropriate for visualizing data on top of basemaps. You can set properties for feature layers—such as style, transparency, visible range, refresh interval, and labels—that control how the layer appears in the map. Using a feature layer, you can view, edit, analyze, and execute queries against features and their attributes.
Each type of feature layer meets a different need and, therefore, has slightly different functionality. For a comparison of functionality available with each type of feature layer, see Feature layer functionality.
For information on Open Geospatial Consortium (OGC) features, see OGC.
Hosted feature layers
Hosted feature layers are feature services for which feature data is hosted by, or stored in, one of two system-maintained data stores.
You can think of the layer, service, and its data as a single entity. When you create a hosted feature layer, the data is copied into one of the system managed data stores. When the owner of the hosted feature layer or an administrator deletes a hosted feature layer, the service and data are also deleted.
Hosted feature layers are created when you
publish a feature layer to ArcGIS Enterprise from ArcGIS Pro or from files in the portal.
ArcGIS Server feature layers
If you have access to feature services running on a stand-alone or federated ArcGIS Server site, you can use these ArcGIS Server feature services as layers in your organization. These layers are similar to hosted feature layers with the following differences:
- The data is not copied into a system-maintained data store; it stays in the data source you registered with the ArcGIS Server site.
- When you delete the ArcGIS Server feature layer, the data is not deleted.
- Much of the configuration for ArcGIS Server feature layers is performed in ArcGIS Server Manager, not the portal.
- Functionality available in the portal is different for ArcGIS Server feature layers than for hosted feature layers.
Many of these differences guard against unwanted changes being made to the data stored in the folders and databases you registered with an ArcGIS Server site, as this data is often your system of record and is likely accessed directly by other applications. However, the hosted feature layer data is managed through the portal and not directly accessed by other applications.
When you publish a feature layer (feature service) to a federated ArcGIS Server site, it is automatically added as a feature layer to your organization. If you want to work with a feature service from a stand-alone ArcGIS Server site, you can add it to your organization as an item. This allows you to reference the REST endpoint (URL) of the service and use the layer in maps and apps while leaving the data stored in the data sources you registered with the ArcGIS Server site. You can also add ArcGIS Server feature layers to Map Viewer or add them to Map Viewer Classic.
Layers in an ArcGIS Server map or feature service
You can add individual layers in a map service or feature service as an item or to a map in Map Viewer or Map Viewer Classic. This allows you to use a single layer in the service in a map or app instead of having to use all layers in the service.
For example, if you have access to an ArcGIS Server map service that contains a roads layer, a buildings layer, and a railroads layer, but you only need to access the roads, you can add the roads layer as an item (recommended if you need to provide credentials to access the service) or directly to a map. To do this, you need to copy the roads layer's URL from the REST endpoint of the map service. The URL for a map service's REST endpoint is in the format https://<server>.<domain>/server/rest/services/<service_name>/MapServer. A link for each layer in the service is listed in the Layers section of this page. Click the link for the layer you want to use. Copy the URL of the page that opens to obtain the layer's URL.
Note:
Feature layers created from a layer in a map service are read-only; you cannot enable editing on them.
Feature collections
Feature collection items are a subset of feature layers with focused and limited functionality. They are derived from other data sources, such as when you save a map notes layer or .csv file in Map Viewer Classic. When you save these map layers as their own items, the items appear as new, read-only feature layers in My Content that you can share with others and add to multiple maps.
Feature collections can also be exported from hosted feature layers that allow data exports. However, feature collections support limited styles and cannot be used in Map Viewer.
Streaming feature layers
Streaming feature layers are feature layers created from an ArcGIS GeoEvent Server stream service. They are useful for visualizing real-time data feeds that have high volumes of data or that have data that changes at unknown intervals. For example, a fleet of vehicles might be transmitting their location, and the current location of the vehicles needs to be continuously monitored. When you add a streaming feature layer to Map Viewer Classic, you can use streaming controls to filter the data that the service sends to the layer. Streaming feature layers can be identified by their icon 
in the content page.
Streaming feature layers connect to an ArcGIS Server stream service using HTML5 WebSockets. Most modern browsers support WebSockets.
Feature layer functionality
The following sections list how to create each type of feature layer and compare functionality available with each type in Map Viewer Classic, Map Viewer, Scene Viewer, and item details.
Publishing methods
The following list describes how you create each type of feature layer in an ArcGIS Enterprise portal:
- Hosted feature layer—Add an item to the portal and publish, publish from ArcGIS Pro, create an empty hosted feature layer from a template or an existing feature layer, or define the schema for an empty hosted feature layer. See Publish hosted feature layers for more information.
- ArcGIS Server feature layer—Publish from ArcGIS Pro to a federated ArcGIS Server site, publish from ArcGIS Pro to a stand-alone ArcGIS Server site and add the service to your organization, or publish from data store items in the portal.
- Feature collection—Add a .csv file, shapefile, or map notes to Map Viewer Classic and save the layer or export data from a hosted feature layer to a feature collection.
Map Viewer Classic
All feature layer items can be added to Map Viewer Classic (formerly known as Map Viewer), but the available functionality may differ slightly. The following table compares feature layer functionality in Map Viewer Classic:
| Functionality | Hosted feature layer | ArcGIS Server feature layer | Feature collection |
|---|---|---|---|
Edit (if editing is enabled on the layer) | Yes | Yes | Not applicable; you cannot enable editing on feature collection items |
Yes | Yes | No | |
Yes | Yes | Yes | |
Define labels | Yes | Yes | Yes, but not supported for map notes |
Yes | Yes | No | |
Yes | Yes | Yes | |
Apply filters | No | ||
Yes | Yes | No | |
Yes | Yes | Yes | |
Calculate fields in the attribute table | Yes | No | No |
Add fields to and delete fields from the attribute table | Yes | No | No |
Display features aggregated in bins | No | No | No |
Map Viewer
At this time, you can add a subset of feature layer types to Map Viewer. The available functionality for each layer type may differ slightly. The following table compares feature layer functionality in Map Viewer:
| Functionality | Hosted feature layer | ArcGIS Server feature layer |
|---|---|---|
Edit (if editing is enabled on the layer) | Yes | Yes |
Add to map with full editing control | No | No |
Yes | Yes | |
Define labels | Yes | Yes |
Set refresh interval | No | No |
Yes | Yes | |
Yes | Yes | |
Duplicate and save as a new layer | Yes | Yes |
Create group layers | Yes | Yes |
Use standard feature analysis tools | No | No |
Calculate fields in the attribute table | Yes | No |
Add fields to and delete fields from the attribute table | Yes | No |
Display features aggregated in bins | No | No |
Scene Viewer
You can add the following types of feature layers to Scene Viewer:
- Hosted feature layer
- ArcGIS Server feature layer
Each layer can contain an unlimited number of features.
Item details
Many of the settings and details you configure for feature layers are the same for all feature layers and for portal items in general, such as setting tags and categories, setting a summary and description, enabling delete protection, and setting an extent. Settings and details that are different across feature layers are listed in the following table:
| Functionality | Hosted feature layer | ArcGIS Server feature layer | Feature collection |
|---|---|---|---|
Publish other layers from | Yes | No | Yes, a hosted feature layer |
Create views from | Yes | You cannot create views from the feature layer in the portal, but the equivalent workflow is to publish multiple feature layers from the same data in ArcGIS Pro. | No |
Define view areas on the Visualization tab | Yes | Not applicable | Not applicable |
Export data from | Yes | No | No |
Add and view metadata | Yes | Yes | Yes |
Yes | You cannot enable attachments on the layer in the portal. However, you can enable attachments on the source data before publishing the feature layer. | No | |
Yes | You cannot overwrite the layer in the portal. However, you can overwrite from ArcGIS Pro. | No | |
Append data | Yes You can also use the Append geoprocessing tool in ArcGIS Pro. | You cannot append to the layer in the portal. However, because the data resides in the ArcGIS Server site's registered data store, you can append to the source data. | No |
Calculate field contents on the Data tab | Yes | No | No |
Add or delete fields on the Data tab | Yes | No | No |
Yes | No; you can view existing lists and ranges but not add or delete them on the Data tab. | No | |
Yes | No | No | |
Enable or disable unique constraint on columns | Yes | No | No |
Edit nonspatial field values on the Data tab | Yes | Yes | No |
Alter field properties including display name (title), description, field value type, and whether edits are allowed for a field | Yes | No | Can edit display name, description, and field value type but not the other field properties. |
Apply filters on the Visualization tab | Yes | Yes | No |
Yes | You cannot enable editing or modify editing settings in the portal. Configure editing settings when you publish the feature layer or modify settings in ArcGIS Server Manager after publishing. | No | |
Enable sync for offline use | Yes | You cannot enable sync in the portal. This is set when publishing, or you can modify the setting in ArcGIS Server Manager after publishing. | No* *Sketch layers and map notes layers saved as part of a web map are automatically enabled for offline use. Other feature collection layers or layer items do not support offline use. |
Yes | You cannot enable editor tracking in the portal. However, you can enable editor tracking on the source data from ArcGIS Pro. | No | |
Control whether editable layers can be shared with everyone (public) | Yes | No | No |
Update details, data, and visualization configuration for individual sublayers | Yes | Yes | No |