There is no set time to stop using diapers on babies because you know what? they are all different. However, while some show signs of readiness and stop as early as two, others may not be ready until they are three. For instance, my girls stopped wearing diapers earlier than their brother. At two they were no longer padded, could say when they wanted to use the potty and stayed dry the whole time.
I noticed my body started staying dry at nights so we stopped wearing diapers but there were a few nights he still poured, so I started wrapping him up at nights again, he is two.
During the day, he is not predictable, sometimes he let’s us know when he wants to pee or goes straight to his potty, at other times, he just quietly wets the floor and then points to it and struggles to take off the wet pant. So, we started wearing again until he is consistent with signs or dryness at night. In the morning, he wears diapers to school, when I go to pick him up, he’s in just pants and school uniform and he stays that way until bed time.
I would say it depends on your baby. S/he will show signs of readiness between 2 and 3 years, just go with the flow and don’t try to force train. From 2 years on , even after they wet themselves , it’s advisable to still put to sit on the potty. These days, most parents start training their babies as early as one year six months. By two years, most African Asian and European children are potty trained and may not need diapers any more.
At 3 years, every baby should have stopped wearing diapers if there are no health challenges.