Lithium dendrite growth in inorganic solid-state electrolytes acts as a main stumbling block for the commercial development of all-solid-state lithium batteries. Indeed, Li dendrites often lead to solid-state electrolyte fractures, undermining device integrity and safety. Despite the significance of these issues, the mechanisms driving the solid-state electrolyte fracture process at the microscopic level remain poorly understood. Here, via operando optical and ex situ dark field X-ray microscopy measurements of LiSn∣single-crystal Li