Will it work on hiking trails and at high altitudes?

The ETravelSim Switzerland eSIM works on most popular Swiss hiking trails up to around 2,000 to 2,500 metres altitude, including the Bernese Oberland routes around Grindelwald, Interlaken, and the Eiger Trail. Above the tree line and on glacier crossings, signal becomes patchy on every Swiss carrier. Swisscom has the broadest mountain reach of the three Swiss networks, but no carrier has full coverage above 2,500m. Save offline Komoot or SwitzerlandMobility maps before any serious mountain hike.