In Jain cosmology, Siddhashila is the realm at the very top of the universe where liberated souls (siddhas) reside. The term Siddhaloka is usually used to refer to the same realm—the abode of the perfected souls after liberation.

So, Siddhaloka is not lower than Siddhashila; they are effectively the same place, with Siddhaloka often simply another name for Siddhashila. Some texts may emphasize nuances in description, but the essential idea is that both denote the realm of liberated souls beyond the worldly lokas.