Migrate from Felt

• Felt and Mergin Maps ecosystems
• Migrating from Felt to Mergin Maps
  • Migrating your collected data
  • Migrating your background maps
  • Recreating your surveys
  • Using Mergin Maps
• Troubleshoot
• Credits

This guide is intended for current Felt users who are considering switching to QGIS and Mergin Maps. It may also be helpful to Mergin Maps users looking to transfer their maps and field data from the Felt ecosystem.

Getting familiar with Mergin Maps and QGIS

Switching to a new platform can be challenging. This documentation is here to help with the basics as well as some more advanced or specific settings.

To get familiar with Mergin Maps, we recommend starting with the tutorials. If there are specific topics that are crucial for your workflows, feel free to explore the documentation or contact our sales team or our support team to get more details.

QGIS is a powerful tool that comes with great community and resources. We recommend using QGIS User Guide and QGIS Training Manual to explore its functionality.

Felt and Mergin Maps ecosystems

Mergin Maps is a platform that seamlessly integrates QGIS projects, providing a familiar workflow for GIS professionals. This connection ensures that Mergin Maps users can benefit from the styling options, attributes form design, and data management capabilities provided by QGIS.

Felt is a browser-based mapping platform built around the map as the central object. Data is brought into a map by uploading files, pasting URLs or connecting a cloud data source, styled in the browser, and annotated on top. Field data is collected with the Felt Field App for iOS and Android, which works against the same map and syncs back to it.

Key differences between the platforms include:

• Projects and maps

  In Felt, the map is created in the browser and everything is assembled there: layers are uploaded or connected, then styled in the web interface, and the field app opens the resulting map on the device.

  Mergin Maps follows the logic of a QGIS project: a project holds all the survey layers, background maps, symbology and forms together. You prepare it once in QGIS on your computer and synchronise it to every device, which means the same desktop project you already use for analysis and map production is the one your field team carries.

• QGIS interoperability

  Both platforms connect to QGIS through a plugin, but the two plugins do different jobs.

  The Add to Felt plugin publishes the visible layers of your QGIS project to Felt, either as a new map or into an existing one. It is a publishing step, so work done afterwards in Felt stays in Felt.

  The Mergin Maps QGIS plugin keeps the project and the platform in sync in both directions. You create the project from QGIS and push it to your workspace, then pull to bring down everything that has changed since your last synchronisation. Styling, forms and layers you adjust on the desktop go back up the same way, so the QGIS project stays in the single place where the project is defined.

• Layers, features and attribute forms

  Felt distinguishes between layers, which hold structured data and can be given attributes, and annotations, which are simply drawn on top of the map for markup.

  Mergin Maps makes a familiar distinction between annotations and layers, except annotations are spatial layers as well, stored in GeoPackages. The schema for created layers is standard, and it can be enhanced in QGIS through forms. Forms are configured in QGIS with widgets: besides text, numbers, dates and value lists, you can use photos, relations, default values, constraints and conditional visibility to build forms that guide the surveyor and validate the data as it is entered.

• Sharing data between the office and the field

  Felt keeps the working copy of the data on its servers and the field app edits that copy.

  Mergin Maps synchronises the whole project. Changes made in the field are uploaded to the workspace and changes made in QGIS are pushed back to the devices, with project history recording every version and with support for collaborative editing by multiple surveyors on the same layers. Projects can also be shared as webmaps for colleagues who do not open QGIS.

• Hosting

  Felt is primarily a hosted service, and includes an option for advanced security with a self-hosted virtual private cloud.

  Mergin Maps can be used as a hosted service or installed on your own server, which is often a requirement for organisations that need their data to stay on their own infrastructure.

• Supported formats of background maps

  Both platforms read common GIS formats.

  QGIS additionally connects directly to PostGIS, WMS, WMTS, WFS, XYZ tiles, MBTiles and many other sources, so most of what you have connected in Felt can be reconnected in QGIS without exporting anything. See the list of supported formats.

Migrating from Felt to Mergin Maps

Migrating your collected data

Felt layers can be exported in formats that QGIS reads directly. Vector layers can be exported as GeoPackage, GeoJSON, Shapefile, KML, CSV, or GeoParquet, and raster layers as GeoTIFF. Annotations are exported separately, as GeoJSON.

TIP

GeoPackage is the best target format, because it preserves attribute types and is the format Mergin Maps uses for survey layers.

To migrate your data:

1. Export your layers from Felt. To export a layer, select it and go to Felt > File > Export Selected. Alternatively, right click on the layer, and select Export.
2. Export all your annotations or only the selection, from the Felt > File menu.
3. Create a QGIS project and save it in a local folder, next to the exported files.
4. Load the exported file(s) in QGIS. If needed, use Refactor Fields from the Processing Toolbox to restore attribute types that the exchange format may have flattened into text, and save the outputs as GeoPackage layers.
5. Apply symbology to your layers and configure their forms with appropriate widgets, for example List of Values for a drop-down menu in your surveys, Date and time for date fields and Checkbox for true/false fields.
6. For photos collected in the field, use the Attachment widget. The image files have to be placed in your local project folder, so that they are synchronised together with the data. If images were attached to features as an attribute in Felt, the exported GeoPackage keeps the links to Felt's servers, and you can use them to retrieve the files.
7. Upload the QGIS project to your Mergin Maps workspace using the Mergin Maps QGIS plugin. The project then synchronises to every device, where it is opened with the Mergin Maps mobile app.

Data already in a database

If your Felt layers come from a PostgreSQL/PostGIS database, there is no need to export anything. In QGIS, connect to it from Layer > Data Source Manager > PostgreSQL. You can also use DB Sync to keep the database and the Mergin Maps project in step, so field edits land back in the database automatically.

Migrating your background maps

Background layers can be moved over or simply reconnected:

1. Layers that you connected in Felt by URL, such as XYZ tiles, WMS, WMTS or Esri services, can be added to QGIS with the same URL, through the Browser panel. See Background Maps.
2. Georeferenced rasters that you uploaded to Felt can be exported as GeoTIFF and added to the QGIS project as raster layers.
3. Keep raster file size reasonable and build overviews (pyramids) for large rasters, so that the map stays responsive on mobile devices. For offline use, consider packaging background maps as MBTiles.

Felt basemaps

The basemaps provided inside Felt are part of that platform and cannot be transferred. QGIS offers a wide range of background map options instead, from XYZ services to your own tiles.

Recreating your surveys

A Felt survey defines which attributes the field app asks for. The same result is achieved in QGIS by configuring the layer form:

1. Recreate each survey attribute as a field of the same type in the GeoPackage layer. You can do that by opening the layer’s properties and selecting Fields tab.
2. Then go to Attributes Form (still in the layer’s properties), set up the corresponding widget for each field, and use default values and constraints to keep entries consistent and validated at the moment of capture.
3. For longer surveys, organise the fields with tabs and groups and use conditional visibility so that surveyors only see the questions that apply.

Using Mergin Maps

To use your QGIS project within the Mergin Maps platform:

1. Sign up to Mergin Maps
2. Install the Mergin Maps QGIS plugin
3. Install the Mergin Maps mobile app
4. Synchronise the QGIS project to the mobile app using the QGIS plugin. See how the settings done in QGIS translate to the mobile app.

Troubleshoot

Struggling to migrate your projects? We are happy to help you!

Book a short video call with our sales team or write to our support team with your technical questions. You can also chat with our open-source community.

Join our community and ask questions!

If you are looking for a professional partner to migrate your workflow, you can ask our partners network or Lutra Consulting Ltd., the developers of Mergin Maps.

Credits

Felt is developed by Felt Maps, Inc., which owns the corresponding trademarks.