CDC Milestone Tracker

From birth to 5 years, your child should reach milestones in how he plays, learns, speaks, acts and moves. Track your child’s development and act early if you have a concern. Skills such as taking a first step, smiling for the first time, and waving “bye bye” are called developmental milestones. Children reach milestones in how they play, learn, speak, act, and move.

https://www.cdc.gov/ncbddd/actearly/milestones/index.html