There is no tread at all, just a little bit in the extreme corner of the sole. The sole is firm and flat. There is no grip at all when standing on a hard floor and not a rug or rug. I got used to it like I got used to going on ice in the winter. Remember that wearing these slippers is dangerous as they are slippery like ice. I wonder why they decided to make these slippers slippery and dangerous. Ha. They put panties in slippers lol! Yes. Very funny.