Is it Haram/Halal to use a soap that contains gelatin?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The ruling on the use of gelatin in Sharia depends on: (1) kind of animal from which this material was taken; and (2) that animal being slaughtered according to Sharia.
Thus, if the gelatin is taken from an eatable animal, slaughtered in accordance with Sharia, then it is pure and permissible. But, if the gelatin is taken from the dead animal not slaughtered Islamically, then it is Haram to be used in food or anything else.
Therefore, if the gelatin used in the soap is taken from an eatable animal, slaughtered according to Sharia, then there is no blame to use it as long as there will be no harm to use it.
The Prophet (Sallallahu Alaihi wa Sallam) said: "There should be no harming, nor reciprocal harming".
Allah knows best.