When planning a splitboard tour you will certainly not rely on Google/Bing map products alone. Hardcopy maps are great during touring but for tour selection not everyone has the right map at home. Since I’m dealing a lot with maps in my professional life I want to provide a small survey about online map material I found and regularly use. Please add other products that you find useful (e.g. for the French or Swiss Alps).
Regarding terrain heights and contour lines: Be aware that most online map products use elevation data that is generated from the NASA SRTM mission. This digital elevation model has global coverage but only a limited resolution of ~90m and a vertical error of less than 16m. Thus smaller saddles and terrain features are missing. The raw data contains a lot of voids in mountainous regions that account for additional errors due to re-interpolation.
Map1.eu is a great resource for tour planning. It contains most peaks, chair lifts, and provides contour lines. Unfortunately a scale is missing but on highest zoom level on grid equals 1000m.
Map Coverage: Entire Alps.
Outdooractive / Alpenvereinaktiv
The Austrian and German Alpenverein launched a new online portal for tour selection. The map is really great since it can display slope gradients above 30°/35°/40° degrees. The map interface is provided by Outdooractive.
Coverage: Entire Alps
Resolution: 90m for terrain, slope gradients might be derrived from a 30m dataset.
The Zillertal Arena provides a map viewer with great relief shading and high resolution elevation data that goes way beyond the usual 90m SRTM data. Additionally you can enable high quality orthophotos to explore small-scale features.
Map coverage: Tyrol for relief, Zillertal only for topographic layer.
Snowhow Maps provides a map viewer that can also display slope information and satellite imagery.
Map coverage: Entire Alps.
Resolution: 10m for Tyrol, South-Tyrol, Vorarlberg, other areas 30m.
The province of Tyrol provides an own map viewer called tirisMaps. The interface is not very user-friendly but they provide the most labels for POIs and terrain features. It was useful because they were the first who provided slope gradients and better orthophotos than Google/Bing. These layers can now be found in the Outdooractive and Zillertal maps.
Map coverage: Tyrol only.