It's vs. Its: The Apostrophe Rule

It's is a contraction. It always means "it is" or "it has." Read your sentence aloud: if "it is" works, use the apostrophe.

Its is possessive, like his, hers, or theirs. No apostrophe. "The dog wagged its tail."

People mess this up because we learn that apostrophes show possession (Sarah's book). But possessive pronouns never take apostrophes. His, hers, ours, theirs, its.

Try the substitution trick: "The company updated it's website" → "The company updated it is website." Nope. So it's its.