It’s best to wait until kittens are around 12 months old before feeding them adult cat food. Kittens need special nutrition to support their rapid growth and development, so kitten food is formulated with higher levels of protein, fat, and essential nutrients that they need. Adult cat food doesn’t have the same balance, so it might not provide the right nutrients during that critical growth period.

Once they reach about a year old, you can start transitioning to adult cat food. It's a good idea to do it gradually to avoid upsetting their stomachs.