Below you can preview online maps which are available in GPX Viewer.

Google Maps
Google Maps support showing normal, terrain and satellite online maps.

View Google Maps

OpenStreetMap
Online map based on OpenStreetMap data using standard OpenStreetMap style.

View OpenStreetMap

ÖPNVKarte
Worldwide online map highlighting public transport information (busses, trams, trains, stops etc.) based on Openstreetmap data.

View ÖPNVKarte

OpenTopoMap
OpenTopoMap is a online map aiming at rendering topographic maps from OpenStreetMap and SRTM data.

View OpenTopoMap

Stamen
Online maps based on OpenStreetMap data with Terrain, Toner and Watercolor styles.

View Stamen

Mapbox
Mapbox has many beautiful online maps based on OpenStreetMap data.

View Mapbox

HERE
Nice online maps with wide variety of types like terrain, satellite, minimalist and city.

View HERE

Thunderforest
A wide variety of online maps for terrain, outdoors, transport and most famous OpenCycleMap.

View Thunderforest