At four months old, most babies can hold their head steady without support, push up on their forearms during tummy time, hold a toy placed in their hand, and are starting to babble and smile socially. This is a period of rapid change, and the range of “normal” is wide. Here’s what to expect across the key areas of development.
Movement and Motor Skills
Head control is the big physical milestone at this age. When you hold your baby upright, they should be able to keep their head steady on their own rather than letting it flop to one side. During tummy time, most four-month-olds can push up onto their elbows and forearms, lifting their chest off the floor. This builds the upper body strength they’ll eventually need for rolling, sitting, and crawling.
Your baby’s hands are becoming more purposeful. They can hold a toy when you place it in their hand, swing their arms at objects that catch their eye, and bring their hands to their mouth. This hand-to-mouth behavior isn’t just cute; it’s how babies explore texture and develop coordination between what they see and what they touch. You might also notice your baby clasping both hands together at the midline of their body, which is an important step toward later skills like transferring a toy from one hand to the other.
Some four-month-olds begin rolling from tummy to back around this time, though many won’t manage it for another month or two. If your baby hasn’t rolled yet, that’s perfectly typical.
Vision and Tracking
By four months, your baby’s eyes work together to focus on and track moving objects. If you slowly move a toy in an arc in front of their face, they should follow it smoothly with their eyes. Color vision is developing but not yet fully mature. That comes closer to five months, along with better depth perception. In the meantime, babies this age are drawn to high-contrast patterns and brightly colored objects.
You’ll also notice your baby studying faces more intently, watching your mouth when you talk, and turning to look at things across the room. Their visual world has expanded well beyond the close-up range of a newborn.
Communication and Social Skills
Four-month-olds are increasingly social. Expect spontaneous smiles, especially in response to your face and voice. Many babies at this age laugh out loud for the first time, and they’ll coo and make vowel-like sounds (“ooh,” “aah”) when you talk to them. This back-and-forth vocal play is the earliest form of conversation. When you pause, your baby may vocalize as if taking a turn.
Babies this age also start to show clear preferences. They may light up when a familiar person enters the room and become fussy or quiet around strangers. They respond to changes in your tone of voice, often looking concerned if you sound upset or smiling when you sound playful. Crying patterns are also more differentiated now. You can likely tell the difference between a hungry cry, a tired cry, and an “I’m bored” fuss.
Feeding at Four Months
Breast milk or formula remains the sole source of nutrition at this age. Most four-month-olds eat every two to three hours, which works out to about five or six feedings per day. Formula-fed babies typically take four to six ounces per feeding at this stage.
You may be wondering about starting solid foods. While some pediatricians give the green light as early as four months, most babies aren’t quite ready. The signs of readiness include holding the head up consistently, doubling their birth weight (reaching at least about 13 pounds), showing interest in food by watching you eat and opening their mouth, and being able to sit with some support. Many babies hit all of these markers closer to six months. If your baby can’t yet sit with support or still pushes food out of their mouth with their tongue, it’s worth waiting.
Sleep Patterns
Babies between four and twelve months need 12 to 16 hours of total sleep in a 24-hour period. At four months, this is typically split between nighttime sleep and two to four daytime naps. Many babies begin consolidating their nighttime sleep around this age, sleeping longer stretches of five to six hours before waking to feed.
This is also when the so-called “four-month sleep regression” often hits. Your baby’s sleep cycles are maturing from the deep, newborn-style sleep into a more adult-like pattern with lighter stages. That means they may wake more frequently between cycles and have trouble settling back down. It’s a temporary (if exhausting) phase that usually resolves within a few weeks.
Play That Supports Development
The best activities at this age are simple. Place a rattle or soft toy in your baby’s hand and let them practice gripping it. During tummy time, set colorful toys just out of reach to encourage them to stretch and push forward. Placing toys near your baby’s feet gives them something to kick at, which strengthens leg muscles and teaches cause and effect.
A blanket on the floor with a few age-appropriate toys creates an ideal play space. Talk to your baby while they play, narrating what they’re doing or what they’re looking at. Singing, reading board books, and making silly faces all count as developmental stimulation at this stage. You don’t need expensive gear. What matters most is face-to-face interaction and giving your baby the chance to move freely and explore with their hands and mouth.
Signs Worth Paying Attention To
Every baby develops on their own timeline, and a week or two of “delay” in hitting a milestone is rarely a concern. That said, there are some things worth flagging for your pediatrician at the four-month checkup. These include: not being able to hold the head steady when held upright, showing no interest in toys or faces, not making any sounds, not tracking moving objects with their eyes, or having stiff and rigid limbs (or conversely, seeming unusually floppy). Losing a skill they previously had, like no longer smiling when they used to, is also worth mentioning.
Early intervention programs are available in every U.S. state and are most effective when concerns are identified early. If something feels off to you, it’s always reasonable to bring it up, even if you can’t pinpoint exactly what’s different.