ArcGIS Hub provides file downloads for several item types that are added to a site’s content library. Various file formats are available depending on the type of item. For example, spatial data (feature layers, feature services, and map services) are supported in .csv, .kml, shapefile (.shp), and GeoJSON formats. You can also enable support for file geodatabase downloads.
How downloads work
Downloading is a process where someone requests a file format for an item that is available for download in a site's content library.
File generation
When someone requests a download on an item's preview page, one of the following occurs:
- For hosted layers, ArcGIS Hub checks for changes before refreshing the cache. If a dataset has been changed or updated since the cache was made, ArcGIS Hub refreshes the cache. Otherwise, the download comes from the previous cache.
- For services hosted elsewhere (for example, on-premises servers), ArcGIS Hub refreshes the cache if it has been more than 24 hours since the last refresh. If it is within the 24-hour period, the user gets the data as it was last cached.
To manually reset the data cache, see Update content.
Private downloads
ArcGIS Hub allows authenticated users to search for and download data and documents that have been shared privately with them through a group or with the organization. To make supported items available for download privately, enable the Export data setting on the item's detail page in ArcGIS Online . ArcGIS Hub relies on the extract capabilities of the underlying service. For more information, see Export data from hosted feature layers.
Recommendations and limitations
Review recommended configurations when making items available for download.
Enable downloads
To make any item available for download in its supported file formats, an administrator or user with the create items privilege must ensure that the Export data setting is enabled for the item. Doing so also allows ArcGIS Hub to use a different pipeline when creating download files. This pipeline is better at handling large items with many records and/or complex geometry. You can also use this setting to enable the file geodatabase download option and make private data available for download. For more information, see File geodatabases.
Note:
In addition to enabling data for export, ArcGIS Hub creates an exported item on an authenticated user’s account. In ArcGIS Online, users will see an “item-export” folder where these exports are stored. When a user downloads an updated file, they will see an additional item in this folder.
Default download formats
ArcGIS Hub supports the following formats by default:
- Feature layers, feature services, and map services support .csv, .xlsx, .kml, .shp, file geodatabase, .geojson, and feature collection formats (private downloads only)
- Image services support .jpg, .png, .tiff formats
- Tables support .csv
- Other specific item types can be downloaded in their native format (ex. a GeoJSON item can be downloaded as .geojson)
Note:
Field lengths, field precision, and scale may be altered in the download. The download process changes the data schema so that all values will be within the signed range of integer values that can be stored in 32 bits. The data itself does not change.
Local projections
The Local Projections setting checks whether the spatial reference of the content is different from the default EPSG:4326. When enabled, public content is downloaded in the custom projection. The spatial reference id of the service must be numeric (not textual). To enable this setting, see Data in Configure site settings.
Note:
For private downloads, ArcGIS Hub automatically uses the spatial reference that is set on the underlying service.
Editor tracking
ArcGIS Hub uses the “last edit date” on a service to know when a service was updated and if a cached file is out of date. This allows ArcGIS Hub to display status messages to visitors, such as “File Generation in Progress” and “The file does not yet exist.” Editor tracking also ensures that dates displayed on the content view are accurate. For more information, see editor tracking.
Large files
Large files with many records and/or complex geometry will take time to update and generate in the download format selected by a visitor. For large or frequently updated content, publish hosted services when possible. If you want to share a .csv file, for example, choose to host it as a table and then add the hosted service to a site's content library. See Publish hosted feature layers and Upload content using a URL for more information.
Additional support for download files
ArcGIS Hub provides several additional download formats that can be enabled by an ArcGIS Online administrator or item owner. All vector datasets are automatically available for download as .csv files, .kml files, and shapefiles and are accessible in the GeoJSON and GeoService APIs.
File geodatabases
For spatial datasets, you can go to the item details page in ArcGIS Online to add file geodatabase as an available download format in the item's content view. For more information, see Enable file geodatabase download.
Tip:
This setting is recommended for public data to hasten the download process. For nonhosted feature services, add custom distributions to the service's structured metadata.
Excel and feature collection files
Private content can be downloaded as Excel files or feature collection files. This is because ArcGIS Hub uses a service’s export function when downloading private content. The same formats are included in the export options on the item's content view as a download option.
External formats
Site owners and core team members can provide links to files or documents that are not supported natively in ArcGIS Online, such as CAD files, non-hosted files, and geodatabases. To add an additional resource, open the item's details page in ArcGIS Online. Select Metadata, Distribution, then Online resource.
Tip:
If the Metadata button is hidden, have an ArcGIS Online administrator enable metadata.
Provide a link for URL and a Name, and set Function to Download. Additional resource links appear on the item's content view on the side panel (at bottom) when selecting the Download button 
.
Note:
At this time, additional resources are only supported for items that reference a feature service or a map service.