Until what age do babies breastfeed?

Until you stop them! Some mothers have breastfed well into childhood. Most happy breast feeders will continue until you stop them. If you can give them at least six months, you have provided many healthy benefits.
Up to a year. Any amount of breast feeding is beneficial to your baby. The first 4-6 months is when your baby will benefit the most from the immune benefits of breast milk. Nursing is a good source of nutrition for the first year of life; solid foods are usually added around 4-6 months of age. The world health organization supports nursing even until age 2. Most us children switch to whole milk at 12 months.