Comparing it to other classic treks in the Alps, the Haute route is the most difficult out of all of them. Each day features a lot of distance, ascent, and descent, with the routes often rocky, exposed, and steep. For comparison, the Haute Route’s average mountain pass is as difficult as the most difficult part of the Tour du Mont Blanc.
Still, the Haute Route is a hike first and foremost, and only a few rare sections demand the use of hands.
More about the Walker’s Haute Route difficulty