The only way to tell is to try and see. Of the chair has a 5 point harness then its almost certainly fine. Come new high chairs are padded and concave and offer a lot of support. Also some high-chairs recline.

Most highchairs have different reclines to them. If this is the case with yours, slant it back as far as it goes and gradually put it up levels as your baby progresses with his sitting-up. Always supervise your child while in the seat for safety.

Wait until the baby can balance himself and sit still for a long period of time before high chair.

Some babies will also grip the try to help keep themselve upright. if he slumps to the side or fusses then he isn’t ready.

When baby get 4 months, you can try to train your baby use the high chair. Don’t forget strap your baby into the highchair every time you put them in there. That way, you’ll do it every time out of habit and get them used to it as well.

In the early days, there is little chance of them climbing out but as they get older, they will start wiggling out and you don’t want the first time they try to be the first time they fall out.

However the ability to sit in a high-chair, particularly one that is reclined or has a 5 point harness is NOT an indication that a baby is ready to eat non-breastmilk non-formula foods.