Downloading Reference Layers for Offline Use
Reference layers — government-published datasets such as vegetation maps, cadastre boundaries, and protected area overlays — normally require an internet connection to display. When field teams work in remote areas without mobile coverage, those layers disappear. Offline reference layer bundles solve this by pre-downloading the tile data and bundling it into the survey package that gets pushed to field devices.
What offline reference layer bundles are
An offline bundle is a packaged set of map tiles for a specific reference layer, clipped to your survey area and covering a defined zoom range. Once a bundle reaches Ready status it is automatically included in the next survey package sync, making the layer available on mobile without any connectivity.
Bundles are created and managed per survey — the same reference layer can have different bundles in different surveys, each covering that survey's area.
Navigating to the offline layers section
- Open your project and select the survey you are preparing for field work.
- On the survey detail page, click the Offline Layers tab in the section navigation.
The Offline Layers section shows the storage summary at the top and a list of all reference layers configured for your organisation below it.
Downloading a reference layer
To start a download:
- Find the reference layer you need in the list.
- Toggle the Download for Offline switch to the on position (it turns green).
- The download starts immediately — you do not need to confirm.
Before the download begins, each layer row shows an estimated file size. This estimate is based on the layer's configured zoom range and the number of tiles that would be needed to cover the survey boundary.
50,000 tile limit: Each bundle is capped at 50,000 tiles. If the estimate shows the layer would exceed this, the zoom range must be reduced in the reference layer configuration before downloading. Contact your admin if you need the zoom range adjusted.
Bundle status indicators
After toggling on a layer, the status changes through several stages:
| Status | What it means |
|---|---|
| Queued | The download request has been received and is waiting to start |
| Fetching | Tiles are being downloaded from the source service — a progress bar shows percentage complete and tile count |
| Packaging | Downloaded tiles are being assembled into an offline bundle file |
| Ready | The bundle is complete and will be included in the next survey sync to mobile devices |
| Failed | An error occurred — click Retry to try again |
| Expired | The bundle is older than 30 days and has been deactivated — click Refresh to re-download |
When a layer is ready for offline use
A Ready badge appears on the layer row when the bundle is complete. The row also shows:
- Total tile count
- File size of the bundle
- Creation date
- Expiry date
Once a bundle is ready, it is automatically included in survey packages pushed to mobile. Field researchers do not need to take any action — the layer will appear in their map when they open the survey offline.
Bundle expiry and refreshing
Offline bundles expire 30 days after creation. This prevents field devices from using significantly outdated data — especially for frequently updated datasets like vegetation condition or land parcel records.
When a bundle expires:
- It is marked Expired and removed from survey packages on the next sync.
- Click Refresh on the expired bundle to download a fresh set of tiles.
You can also refresh a bundle at any time before expiry to pull in the latest data from the source service.
Removing an offline bundle
To stop a layer from being included in offline survey packages, toggle the switch off. A confirmation dialog will ask you to confirm before the bundle is deleted.
Removing a bundle frees up storage and removes the layer from future survey syncs. Field devices that have already synced the bundle retain it until the device's local package is refreshed.
Related Articles
- Managing Offline Reference Layer Storage — Understanding storage use and managing bundle size
- Adding government reference layers to your map — How reference layers work in the Map Workspace
- Map Workspace — Overview of the map and layer management