Prepare for offline data collection

Note:

The ArcGIS Collector help site is retired and no longer being updated. To learn about ArcGIS Collector retirement and to find the latest information on data collection, see Collector retirement.

In the field, mobile workers often work in areas without a reliable data connection, or with no data connection at all. For these situations, mobile workers can download areas of the map to make them available offline. Once map areas are downloaded, mobile workers can use them to capture assets and observations and perform inspections the same way they do when connected.

Collector supports downloading both map areas defined as part of the map and map areas defined in the app. If you know where your mobile workers will be working, such as a region of the country or a service area, you as the map author should define and prepare map areas as part of the map in ArcGIS Online or ArcGIS Enterprise. Those defined map areas are available to mobile workers to download in Collector. If mobile workers need to go offline in a location that wasn't prepared ahead of time—where there is unplanned work, for example—the mobile worker can use Collector to define and download a map area.

Take the following steps to enable mobile workers to download maps in Collector:

• Ensure that your data meets the data requirements.
• Create a basemap to copy directly onto devices (optional).
• Configure a map for offline use. Make sure to optimize download and sync so that mobile workers get the information they need, create map areas (if defining them for your mobile workers), and reference a basemap (if using one already on your mobile worker's devices).
• Configure Collector to work offline:
  • Copy a basemap to the device (optional).
  • Download a map area.
  • Enable automatic sync (optional).
  • Download and sync over Wi-Fi only (optional).

Maps with offline areas are used offline even if the device has a data connection. Collected assets, observations, and inspections must be synced before they are available to other users. When work with a downloaded map area is complete, the map area can be removed from the device.

Data requirements

Maps downloaded in Collector must meet the data requirements for maps used in Collector in addition to having all layers enabled for offline use. See Enable the layers and map for offline use in ArcGIS Online or Enable the layers and map for offline use in ArcGIS Enterprise.

Create a basemap to copy directly onto devices (optional)

You can copy a basemap directly to the mobile worker's device (this process is called sideloading) and reuse it across multiple maps. This has a few advantages over downloading the basemap along with the map area: in most cases, it is faster than downloading the same basemap, and it also allows you to prepare basemaps for much larger areas. Additionally, basemaps copied to the device are available to all mobile workers who use Collector—each user won't need to have their own copy, saving space on shared devices. To do so, you need to create a basemap tile package.

If you want the copied basemap to be the default used when downloading the map (avoiding downloading the basemap along with the rest of the data), the map must reference it and it must be copied to the mobile worker's device.

Configure a map for offline use

Creating a map for offline use is the same as creating one for online use, with a few additional requirements. Maps that meet the offline requirements automatically support downloading map areas in Collector. Once your map is created, optionally configure it for offline use by creating map areas as part of the map (if providing ready-to-download map areas to your mobile workers), optimizing download and sync, and referencing an on-device basemap. If you are using ArcGIS Enterprise but want to take an Esri basemap offline with your map area, you must also add an Esri basemap from ArcGIS Online to your map.

Tip:

To disable downloading a map in Collector, uncheck the Enable offline mode check box in the map's item details. For details, see Offline options in ArcGIS Online or Offline options in ArcGIS Enterprise. You won't see the Offline mode options if your map doesn't meet the offline requirements.

If you are using ArcGIS Enterprise 10.6.1 or earlier and your map contains a vector tile layer, map areas aren't downloadable by default. If all your layers meet the offline requirements (all feature layers support sync and all raster and vector tile layers support export), edit your map's item details and add the tag Offline-Ready. Then you'll be able to download it.

Create map areas as part of the map (optional)

Creating map areas as part of your map allows you, as the map author, to prepackage one or more areas of a map so that mobile workers in Collector can download them without having to configure the extent or level of detail. See Create, edit, and manage map areas in ArcGIS Online or Create, edit, and manage map areas in ArcGIS Enterprise.

If you are using ArcGIS Enterprise, the interactive experience for creating map areas (as in ArcGIS Online) was introduced in ArcGIS Enterprise 10.7. If you are using ArcGIS Enterprise 10.6.1, map areas must be managed through ArcGIS API for Python.

Note:

Once map areas are created as part of your map, mobile workers won't be able to use the map without downloading a map area. Until it's synced, their captured assets, observations, and inspection information are only on their device. Updates from other workers won't be available without syncing, either.

Optimize download and sync (optional)

By default, mobile workers download and sync all features and attachments for both editable and read-only layers. However, mobile workers don't always need all of this information to complete their work. Also, your organization may want to limit the size and amount of data mobile workers retrieve from the server during initial download as well as subsequent sync operations. This can make it faster for mobile workers to share changes, and it minimizes data transfer costs. This is especially true when your mobile workers are in areas with low bandwidth. You can limit the types of data mobile workers retrieve from the server by adjusting the advanced offline options of your map. The options won't affect edits made by the mobile worker; those are always sent to the server. This section provides examples of when you might not want mobile workers to retrieve features or attachments. For more details about how to change these settings, see Choose the right advanced offline options in ArcGIS Online or Choose the right advanced offline options in ArcGIS Enterprise.

• If mobile workers are capturing new assets or observations and do not need knowledge of existing assets and observations, you might not want them to retrieve features and attachments. Mobile workers receive less context, but the time and cost for them to share edits is minimized. Mobile workers will see the assets and observations they have added since downloading the map area. They won't see assets and observations added by others or those they added if they had worked with the map before this download.
• If mobile workers are inspecting existing assets or observations, you might want them to retrieve only features. You might not want them to retrieve attachments, because they can be large. Mobile workers will not see attachments of existing assets, but they will see their locations and attributes, which might be all they need to know to complete their jobs. Preventing the retrieval of attachments may also decrease the time and cost to share edits.

Note:

There are different settings for editable and read-only layers in the advanced offline options. However, if you have multiple layers that come from the same service and at least one of those layers is editable, all the layers from that service honor the settings of the editable layer. For example, if you configure your map so that you get attachments on editable layers but not read-only layers, but one of your read-only layers comes from the same service as an editable layer, that read-only layer's attachments are retrieved.

Reference an on-device basemap

You might want your mobile workers to download only operational layers and not the basemap of a map, instead using a basemap you created to copy directly to their devices. As part of authoring your map, specify a tile package to use for the offline basemap as part of the advanced offline options. If that basemap is on their device, only operational layers are downloaded. If the referenced basemap isn't on the device, the mobile worker can continue and download the map's default basemap with the operational layers. See Use a tile package for the offline basemap in ArcGIS Online or Use a tile package for the offline basemap in ArcGIS Enterprise.

Note:

Specifying a basemap for offline use with ArcGIS Enterprise requires version 10.7 or later.

Use an Esri basemap on ArcGIS Enterprise

You can download an Esri basemap from ArcGIS Online with an ArcGIS Enterprise map. To do so, you must meet the following requirements and complete the following steps:

• You have an account as a member of an organization in ArcGIS Online.
• You are using ArcGIS Enterprise.

1. In the Tiled Basemaps or Vector Basemaps (for Export) group in ArcGIS Online, find the basemap you want to use and open its item page.

   Note:

   Taking Esri vector basemaps offline with ArcGIS Enterprise requires version 10.7 or later.

2. On the item page, in the URL section of the right column, click Copy next to the text box.
3. Sign in to your ArcGIS Enterprise portal, click Content, and go to the My Content tab.
4. Click Add Item and choose From the web.
5. Choose ArcGIS Server web service.
6. In the URL text box, paste the basemap link you copied in step 2. Click the Title text box so that the URL text box is no longer selected.

   The service information is retrieved from ArcGIS Online. It is detected to be secure, and the Username and Password text boxes appear below the URL text box.

7. Provide the user name and password for your account that is a member of an organization on ArcGIS Online and choose Store credentials with service item.
8. Click Add Item.

   The item page for your new item appears.

9. To make your basemap available across your maps, create a map that uses the new layer as the basemap and share it with your organization's basemap gallery. For details on making the map, see Use your own basemap. For details on sharing it with the basemap gallery, see How do I make a layer available as a basemap in my organization's basemap gallery?

   Note:

   The map that is shared with the organization's basemap gallery should only be used for offline use and not for general map viewing.

10. Using Map Viewer, open the map your mobile workers take offline and update it to use the basemap in one of the following ways:
    • If you added it to the basemap gallery, click Basemap, and click your newly created basemap in the basemap gallery.
    • To add the layer as the basemap for only this map, see Use your own basemap.
11. Save your changes to the mobile workers' map.

When you open the map in Collector, you can download it and work offline.

Configure Collector to work offline

To work offline in Collector, download a map area to the device. Optionally, you can copy a basemap directly to the device instead of downloading the one used with the map.

Copy a basemap to the device (optional)

If you created a basemap to copy to devices, provision it directly to the mobile worker's device. On Android devices, this is done by copying the file to the device or SD card. On iOS devices, this is done through the Files app or iTunes. See Copy the basemap tile package to the device.

Download a map area

If a map supports offline use, you can download a map area in Collector. If the map has offline map areas, the text Offline areas displays below the map name. Tap it to show the map areas available for download or to define your own. If the map doesn't have any offline map areas, use the Overflow menu to define and download a map area.

Download an existing map area

To download a map area that was defined as part of the map, complete the following steps:

1. In the list of maps, tap the map that you want to download.
2. Tap a map area.

   The map area begins downloading to the device.

3. Once downloading completes, open the map area and work with it as you would any map in Collector. You can open and use it whether or not you have a data connection.

   Note:

   When using a downloaded map area, you must use a basemap downloaded with the map or copied to your device. Basemaps must overlap the extent of the map area and their spatial reference must match that of the default basemap.

Define and download a map area in Collector

To define and download a map area, complete the following steps:

1. In the list of maps, find the map that you want to download and tap its Overflow menu .

   Tip:

   If the map already has offline areas, tap the map to see its offline areas and tap the Overflow menu to add additional offline areas.

2. Tap Add offline area.
3. Pan and zoom the map so that the area you want to download is visible.

   The initial extent is the default extent of the map. Due to limitations on the number of tiles that can be downloaded, you can't always download the entire extent. A gray mask covers the areas that won't be included in the download. If you don't see a mask, the area on the screen will be downloaded.

   Tip:

   You can use a bookmark to bring an area of interest onto the screen. Tap Bookmarks and choose the area you are interested in.

   

   The unmasked area will be downloaded.

   

   The mask is outside the visible extent. The area on the screen will be downloaded.

   Tip:

   The initial extent can be large and the mask may appear to cover the whole map, making it hard to see the unmasked area. To see the area that will be downloaded, zoom in until you can see the unmasked area.

   

4. If the map uses a raster tile layer (as either a basemap or a reference layer), you'll see Level of detail below the default area name. The value next to Level of detail is an indicator of how far you'll be able to zoom in and see a crisp background on the map area once it is downloaded (beyond that, you can zoom in but it will be pixelated). If the current level of detail doesn't meet your needs, tap the current level to display a list of available levels and choose one to specify the amount of detail you need.

   By default, the downloaded map area uses the highest level of detail supported by the basemap. If you don't need that level of detail, consider choosing a coarser level. This makes the download faster and uses less space on your device.

   If you need to download a larger area than is shown unmasked, change Level of detail to decrease how far you can zoom in without the background becoming pixelated, which increases the downloadable (unmasked) area.

   If your map uses a vector tile basemap, you won't see the level of detail setting. All zoom levels are supported on vector tile basemaps.

   

5. Tap Download area.

   You are taken back to the list of maps and can see the downloading map area.

6. Once the download completes, you can rename the map area by tapping Rename area in the map area's Overflow menu .
7. Open the map area and work with it as you would any map in Collector. You can open and use it whether or not you have a data connection.

   Note:

   When using a downloaded map area, you must use a basemap downloaded with the map or copied to your device. Basemaps must overlap the extent of the map area and their spatial reference must match that of the default basemap.

   If you need to define and download another map area, use the Overflow menu in the toolbar (next to the map name).

Enable automatic sync (optional)

Mobile workers can have sporadic connectivity, or perhaps they don't always remember to sync their changes. Enabling automatic sync sends the mobile worker's edits and retrieves the latest changes when there is a data connection without the mobile worker needing to explicitly sync.

You can enable automatic sync either from the settings in Collector or while working in a particular map. Either way it is enabled, the setting applies to all offline maps used in Collector, and the currently open map area automatically syncs on the specified interval (by default, every 15 minutes) as long as the device has a data connection and the app is on-screen.

Enable automatic sync in the app settings

To enable automatic sync in the app settings, complete the following steps:

Note:

Only iOS supports enabling automatic sync in the settings or specifying an auto-sync interval.

1. While viewing the Maps list, tap Profile .
2. In the General section of the profile, tap Download & sync.
3. Use the Auto-sync toggle button to turn automatic sync on.
4. If needed, choose an interval on which sync is automatically performed if there is a data connection. The default is every 15 minutes. You can also set it to sync every 30 minutes or every hour.
5. Return to your profile, and return to the Maps list.

Enable automatic sync while working with an offline map area

To enable automatic sync while working with an offline map area, complete the following steps:

1. While working in an offline map area, tap Sync ( if you have edits that aren't synced) to open the Sync panel.
2. In the Sync panel, use the Auto-sync toggle button to turn automatic sync on, if it isn't on already.
3. By default, automatic syncing is done every 15 minutes. To specify a different interval (either 30 minutes or 1 hour) on iOS, you need to use the app settings.

Download and sync over Wi-Fi only (optional)

You might not want your workers downloading or syncing using a device's data plan, but instead want them to wait for a Wi-Fi connection. This is enabled by default.

1. While viewing the Maps list, tap Profile .
2. In the General section of the profile, tap Download & sync.
3. Turn on the Wi-Fi only toggle button to restrict downloading and syncing to over a Wi-Fi connection. When off, downloading and syncing can also be done using the device's data plan.
4. Return to your profile, and return to the Maps list.

Tips

These tips will help you be successful working offline:

• Use Auto-sync to avoid forgetting to sync—Encourage the use of automatic sync. This saves mobile workers from having to remember to sync, or keeping an eye on their data connection to see if they can sync. The app syncs for them when it has a data connection.
• Consider the photo resolution required for your assets, observations, or inspections. You can specify a smaller photo size to help reduce the amount of data transferred when syncing.
• Remove downloaded map areas and basemaps—When the mobile worker is done using a map area or basemap, remove it from their device. This frees up space on the device and ensures that the current map is used if the mobile worker needs to go back to it at a later date. Use Collector to remove maps and basemaps downloaded through the app. If you're removing a basemap that was copied to the device through the Files app or iTunes, you must remove it using one of those apps.