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 maps to make them available offline. Once a map is downloaded, mobile workers can use it the same way they do when connected. While they only get updates to downloaded maps on request, downloaded maps allow mobile workers to continue working with GIS data without a data connection.
There are four ways to take maps offline in Explorer, and the one you use depends on the map you are trying to take offline. The information about your map that is presented in the list of maps helps determine the type of download:
- Some maps in the Maps list show that they have offline areas defined and show those map areas if tapped:
If your map looks like this in the list of maps, download an offline area that has been defined for you. For these maps, you can take multiple areas of the map offline.
- Some maps in the Maps list open the map if tapped, and in the list, show an overflow menu with additional actions you can take:
If your map looks like this in the list of maps, define and download an offline area. For these maps, you can take multiple areas of the map offline.
- Some maps in the Maps list must be downloaded to be used:
If your map looks like this in the list of maps, download the map. For these maps, you can take the entire map offline at once.
- Some maps may not appear for download in the app. Instead, you get them from a website, or they were emailed to you, or something similar. These shared files have the .mmpk extension and you need to download the map outside the app and copy it to your device.
When you're finished working with a downloaded map, remove it from the device.
Note:
Downloaded maps and maps with defined offline areas are used offline even if the device has a data connection.
This topic is about using downloaded maps. For information about authoring maps for download, see Prepare maps to use offline.
Tip:
To ensure that your cellular data plan isn't used to download maps, go to the app's settings, tap Cellular Data, and turn off Downloads. To prevent automatic updates from using cellular data, turn off Automatic Updates in the Cellular Data setting as well.
Download defined offline areas
If the map has offline areas defined for you, download one by completing the following steps:
Note:
Maps with offline areas are used offline even if the device has a data connection.
- In the list of maps, tap the map that you want to download.
- Tap a map area.
The map area begins downloading to the device.
- Once downloading completes, open the map area and work with it as you would any map in Explorer. 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.
Tip:
If you don't see the map area you want to download, you can define and download an offline area using the Overflow menu 
while viewing the available map areas.
Define and download an offline area
If the map can be opened and used online, but you want it available without a data connection, define and download a map area by completing the following steps:
Note:
Not all online maps can have map areas downloaded. They must meet the data requirements for downloading.
Maps with offline areas are used offline even if the device has a data connection.
- 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. - Tap Add offline area.
- 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.
- 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.
- Tap Download area.
You are taken back to the list of maps and can see the downloading map area.
- Once the download completes, you can rename the map area by tapping Rename area in the map area's Overflow menu .
- Open the map area and work with it as you would any map in Explorer. 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).
Download a map
Some maps in Explorer must be downloaded to be used. If your map shows a download icon, tap the map to download it. Once downloaded, the map is designated as an On Device map. Tap the map to open it.
Note:
Look for one of the following download icons: Android 
, iPad or iPhone 
, or Windows 
.
Download and copy a map
If you downloaded a map outside Explorer (for example, from a website or it was sent to you in an email), copy it to your device to use it in Explorer. Explorer supports copying maps in .mmpk files.
- iPad and iPhone devices—Use iTunes and connect your device to your computer. See Apple Support for details on using iTunes to share files between your computer and your device and follow the steps to copy the .mmpk file from your computer to the Explorer app on your device.
- Android devices—Connect your device to your computer, use your computer's file explorer to browse to your device, and copy the .mmpk file into the \Android\data\com.esri.explorer\files\mappackages folder.
- Windows devices—Open Explorer. Open the Maps list, tap the Overflow menu, and tap Import Map. Browse to the .mmpk file you want to import and tap Import Map.
Once you copy it to your device, the map is designated as an On Device map. Tap the map to open it.
Note:
If you're using an Android, iPad, or iPhone device and Explorer was open when you copied the map, you must relaunch Explorer or refresh the list of available maps to see the copied map in the On Device maps.
Copy a basemap to the device (optional)
If a basemap was created to copy to your device, provision it directly to your 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. On iOS you must restart Explorer on your device to see the updates made to the basemaps. On Windows devices, this is done by copying the file to the device.
- On Android—Plug your device or SD card into your computer. Using a file explorer on your computer, browse to \Android\data\com.esri.explorer\files\basemaps (if that folder doesn't exist, create it). Copy the basemap file (.tpk, .tpkx, or .vtpk) you want on your device to that basemaps folder.
- Files app (iOS)—Copy the basemap file (.tpk, .tpkx, or .vtpk) you want on your device to a website that is available in the Files app, for example, iCloud Drive, Box, or Google Drive. In the Files app, browse to where you uploaded the basemap file and copy it to your device, placing it in the Explorer folder. See Apple Support for complete steps on using the Files app on your device.
- iTunes (iOS)—Connect your device to your computer and go to your device in iTunes. Browse to the files shared with the device and select the Explorer app. Drag the tile package (.tpk, .tpkx, or .vtpk) into the documents section for Explorer. See Apple Support for complete steps on using iTunes to share files between your computer and your device.
- On Windows—Plug your device into your computer. Using a file explorer on your computer, browse to C:\Users\<user_name>\AppData\Local\Packages\Esri.<unique identifier>\LocalState\basemaps (if that folder doesn't exist, create it). Copy the basemap file (.tpk, .tpkx, or .vtpk) you want on your device to that basemaps folder.
On Android and Windows, the basemap is immediately ready for use. On iOS, the next time you access basemaps, the tile package is moved into a Basemaps folder on your device and is available for use in Explorer.
Tip:
To rename a basemap on an iOS device, use the Files app. In the Files app, browse to the basemap file, long press the file, and rename it. The new name is displayed in Explorer when switching basemaps.
Open and use a downloaded map
Once you download a map to your device, you work with it the same way as an online map. In the Maps list or Map Areas list, tap the map or map area to open it. Then you can pan and zoom and use markup in the same way as any map.
Limitations
There are limitations on the functionality available in downloaded maps in Explorer:
- Place search
While you can still search for your assets without a data connection, searching for place names and addresses requires a data connection. If you have a data connection while using your downloaded map, you can search as you do in an online map.
Update a downloaded map
Maps change over time. More data may have been added to it, or the map author updated the map. If changes are made to a map while you have it downloaded, you won't see those changes until a request (either manual or automatic) is made. Check for updates to get the latest content for downloaded maps. You can check for them anytime you regain connectivity to confirm you have the latest map.
How you get the updated map depends on the type of changes made and the way you downloaded the map you are using.
Note:
A data connection is required to get updates.
Update an offline area
Check offline areas for updates to downloaded changes to the data in the offline areas you use. Checking for updates requires a data connection. Explorer automatically checks for updates every 15 minutes; you can also check for updates manually. Manual requests are made in the list of maps: find the offline area you want to update, tap its Overflow menu , and tap Check for Updates.
When you check for updates, the data in the map is updated at that time. This includes the addition of new assets and updates to existing assets. For example, you have a map with a layer of parks and their amenities. A new park was built in town, and the new park was added to the parks layer. You won't see the new park and its amenities in your downloaded map until you check for updates.
Some changes to the map (as opposed to the data in it) don't appear by checking for updates. Instead, mobile workers must remove the map area from their device and download it again. These types of changes include the following:
- Symbology changes
- Added or removed layers
- Updated layer schemas (including added and removed fields, as well as updated lists and domains)
- Updated search capabilities
- Changes to pop-ups
Update a downloaded map
If your map was downloaded in its entirety (not as areas), check for updates to download all changes. In the list of maps, find the one you want to update. If it's designated as Update Available, tap its Overflow menu and tap Check for Updates.
Update a copied map
If your map was downloaded outside Explorer as an .mmpk file and copied to your device, you must manage updates manually as well. Remove the map from your device the same way you added it, get a new version of the file, and copy the updated file to your device the same way you originally copied it.
Remove a downloaded map
You may need to remove a downloaded map or map area because you're finished with it, updates have been made to the map (not just its data), it's taking up too much space on your device, you want to use it while connected, or you're finished using the device and you're handing it off to a coworker.
Tip:
If you're using a map that was downloaded in its entirety in Explorer (not as areas) or if only the data in your map area has changed, update it instead of removing it and downloading it again.
In the list of maps, find the downloaded map or map area you want to remove. Tap its Overflow menu and tap Remove (for maps) or Remove Area (for map areas).
Note:
Downloaded maps and map areas aren't removed when you sign out, but they are associated with your account and are not available to other mobile workers. However, if left on the device, they do take up space, and the same mobile worker must sign in to remove them.
To use a map while connected, it can't have defined offline areas, and you must remove all downloaded map areas.