Pick one base map underneath, then add any number of overlays on top. The two choices are independent. A base you pick stays picked. TrailRunner Mini never swaps it out on its own as you zoom.
Apple Maps, Satellite and Hybrid come from Apple. Beyond those:
| OpenStreetMap | The community-mapped standard rendering. The most complete trail coverage in most of the world. |
| OpenTopoMap | Topographic styling with contour lines, in the tradition of a printed hiking map. |
| Esri Topo, Esri Imagery, National Geographic | Esri's topographic, aerial and National Geographic cartography. |
Choose Show More in the base-map picker for further regional sources. These are Thunderforest Outdoors, Bergfex Topo, Google Terrain and IGN France. Some are strongest in a particular region. IGN France, for instance, only paints over metropolitan France.
Overlays add information without replacing the map underneath:
| Topographic Features | Contour lines, elevation labels and hillshading. |
| Hiking Trails | Waymarked hiking routes. |
| Cycling Routes | Road and gravel touring networks, such as EuroVelo and national routes. |
| Mountain Bike Routes | The denser, graded MTB network. |
| Sea Marks | Navigation marks along coasts and waterways. |
| Boundaries & Places | Administrative boundaries and place labels. |
On Apple Maps, Topographic Features and Hiking Trails are on by default. The same two toggles work on every base. On Apple Maps they use Apple's own terrain and hiking layers. On the other bases they use community terrain and waymarked-trail tiles. You get the best available version of each without having to think about where it comes from.
Your overlay choices are remembered per base map. Turn contours off on OpenTopoMap, because that base already draws them. Switch to Satellite and turn them on. Each base then returns the way you left it.
Routes are calculated from the OpenStreetMap trail network. This applies whichever base you are looking at. The picture on screen is not what routing follows. A path you can see in satellite imagery cannot be routed along unless it is also mapped in OpenStreetMap. Where no mapped trail exists, use the Straight toggle to connect two waypoints with a direct line.
No source covers the whole world at every zoom level. When a source has no tiles for where you are looking, the result is empty. Nothing is substituted in its place. That is deliberate. Seeing that a map has no data here is more useful than being quietly handed a different map.
Switch to another base map. Apple Maps and OpenStreetMap have the broadest coverage and are the reliable fallbacks. The specialist sources are worth it where they are strong.