Dual Maps

Dual Free Maps URL Parameter Reference

All parameters are optional. Defaults apply when absent. Parameters are passed as a query string to dmf.htm or the Blazor route /dualfreemaps. No Google Maps API key is required — all map sources are open / free.

Core

ParameterTypeDefaultDescription
lat float 51.5074 Initial centre latitude shared across all panels.
lng float -0.1278 Initial centre longitude shared across all panels.
z integer 16 Map zoom level (1–20).
panel string rsm Which panels to display. Combine letters in any order: r = Road, s = Satellite, m = Mapillary. Example: panel=rs hides Mapillary.
pt string none Place title shown in the header. URL-encoded.

Map Sources

ParameterTypeDefaultDescription
left string ofm-liberty Road / base map source for the left panel.
  • ofm-liberty – OpenFreeMap Liberty
  • osm – OpenStreetMap
  • carto-voyager – Carto Voyager
  • carto-dark – Carto Dark Matter
  • carto-positron – Carto Positron
right string esri Satellite source for the right panel.
  • esri – ESRI World Imagery
  • esrih – ESRI World Imagery + labels
cover 0 / 1 1 Show the Mapillary coverage overlay on the road and satellite panels.

Search

ParameterTypeDefaultDescription
search string 1 Address search provider.
  • 1 – OpenStreetMap Nominatim (free)
  • 0 / absent – hide search bar