These two English words are very often used incorrectly by native speakers. It’s important that you understand the difference.
It’s is a contraction of it is or it has.
Its is the possessive form of it.
The Bottom Line
The confusion between it’s and its occurs because with virtually every other word, ‘s indicates possession. Consequently, English speakers naturally want to use it’s to mean "something belonging to it." But it’s is only used when it’s a contraction of it is or it has.
The ironclad rule – no exceptions – is that if you can replace the word with it is or it has, use it’s. Otherwise, it’s always its.