TL;DR:
This stage is full of rapid growth, curiosity, and early interaction. Your 4-month-old is becoming more aware of their body, their surroundings, and you. These simple, safe activities support physical, sensory, social, and cognitive development – all while helping you bond and enjoy this sweet stage.

💡 If you want the full month-by-month breakdown, our Activities for Babies by Age guide offers ideas for every stage from birth to 18 months.

Quick Activities for Your 4-Month-Old (At a Glance)

If you’re tired, and need ideas fast!

Tummy time on a play mat
Baby leg bicycles
Gentle baby yoga stretches
High-contrast toys or cards
Mirror play
Tracking a toy side to side
Head-turn “sound locating” game
Sensory bottles (sealed tightly!)
Exploring different textures
Soft music and sing-alongs
Play gym time
Peek-a-boo
Rolling a soft ball
Baby-safe water splashing
Nature walks in a stroller or carrier
Simple sign language
Chatting narrations
Facial expression play
Board book reading
Baby-wearing
Color recognition games
Object permanence games
Gentle hand + arm stretches
Happy Baby pose
Playdates for early social exposure

(All expanded and explained below.)

💡If your baby is working toward new milestones, you may also find our 3-month activity guide helpful.

Safety First (Important for 4-Month-Olds)

Always supervise your baby during any activity.
Follow safe sleep + tummy time guidelines, avoid choking hazards, and ensure mirrors, bottles, and toys are baby-safe and unbreakable.

Physical Development Activities

Tummy Time

Still one of the most essential activities for a 4-month-old. Helps strengthen the neck, shoulders, and upper body — all building blocks for rolling and crawling.

Try:

A mirror in front of them
A soft toy at eye level
Laying beside them for encouragement

Baby Yoga

Baby yoga doesn’t need to be complicated — gentle movements introduce body awareness, flexibility, and bonding.

Try:

Leg Bicycles: Move their legs gently in a biking motion.
Happy Baby Pose: Encourage them to grab their feet while lying on their back.
Gentle Twists: Move legs side to side for flexibility.
Arm + Hand Stretches: Let them hold your fingers and stretch gently.

Add a nursery rhyme or soothing song to make it fun.

Developmental Milestones + Early Communication

Baby Sign Language: Simple First Signs to Try With Your 4-Month-Old

Introducing basic signs is a sweet way to support early communication. Even though your baby won’t sign back yet, they’re already building language pathways. Keep it playful, repeat signs often, and always pair them with spoken words.

Here are the most useful early signs:

Bring your fingertips together a couple of times in front of your chest.

Milk

Open and close your fist, like you’re gently squeezing.

Eat

Bring your fingertips to your mouth as if feeding yourself.

All Done

Hold both hands open and flip them from palms up to palms down.

Mom

Touch your thumb to your chin.

Dad

Touch your thumb to your forehead.

Play

Extend your thumb and pinky (like the “hang loose” sign) and move your hands side to side.

Book

Hold your hands together like a closed book, then open them.

Sleep

Bring your open hand to your face and pull it down into a closing gesture as if your eyes are closing.

Help

Place one flat hand palm-up, then lift it with your other hand underneath.

Water

Form a “W” with your fingers and tap it to your chin.

Tip: Say the word every time you do the sign. Repetition helps your baby begin connecting meaning long before they’re able to sign back.

Tracking Objects

Move a toy slowly side to side, up and down. Develops early visual tracking, which supports future reading and focus skills.

Head-Turn Sound Game

Make a gentle noise on one side of your baby and wait for them to turn toward it.
Strengthens neck muscles and builds auditory awareness.

Mirror Play

Place an unbreakable baby-safe mirror in front of your baby. At this stage, they’re fascinated by their reflection.

Benefits:

Early self-recognition
Confidence building
Social engagement (babbling, smiling, reacting)
Cognitive connections (movement → reflection)

Tips:

Use a mirror during tummy time
Point to facial features (“nose,” “eyes”)
Mirror their expressions

Facial Expressions Game

Make different faces — smiling, surprised, playful.
This teaches emotion recognition and builds early social skills.

Chat Away

Talking to your baby builds language pathways. Narrate everyday tasks and describe what’s happening around you.

Meet New Friends

Short, calm playdates expose babies to new faces and sounds — great early social practice for your baby!

Reading Time

Board books with textures, bold colors, and simple images help with vocabulary, attention, and bonding.
Point to pictures and describe what you see.

💡If you’re building out your home library, our list of the best books for your nursery has simple, timeless picks that grow beautifully with your baby.

Baby-Wearing

Being close helps babies feel secure while engaging with the world around them.

Sensory Play Activities

Play Gym

A play gym encourages reaching, swatting, grabbing, and visual exploration. Hanging toys help build hand-eye coordination.

Sensory Bottles

Fill a tightly sealed bottle with:

beads
sequins
colored water
pom-poms
glitter glue

They can shake, roll, or explore it visually.

Always supervise and double-check the lid.

Texture Time

Offer different objects for safe tactile exploration:

plush toys
tissue paper
wooden blocks
soft washcloth
metal spoon
soft brush

Babies learn through touch — this is meaningful sensory input.

Sound Exploration

Rattles, shakers, soft music, or gentle singing help babies process different sounds.
Move their hands to the rhythm for added engagement.

Nature Walks

Stroller or carrier walks expose them to fresh air, movement, and new sights.
Point out colors, trees, or sounds along the way.

Sensory Toys

Think crinkle books, soft toys with tags, textured balls, and high-contrast board books.

High-Contrast Toys

Babies at 4 months love bold patterns and high-contrast black-and-white designs.

Gentle Water Play

At bath time or in a shallow baby-safe basin (supervised!), let them splash, kick, or feel water running over their hands.

Cognitive Development Activities

Peek-A-Boo

A classic for a reason — helps teach object permanence.

Object Permanence Games

Hide a toy under a blanket and reveal it.
Helps babies understand that things still exist even when out of sight.

Color Recognition

Use toys of different colors and name them.
Sort toys by color or point to objects you see on a walk.

Fun & Bonding Games

Sing-Alongs

Sing favorite songs or nursery rhymes.
Babies love voice patterns and repetition — and it supports language development.

Dance Time

Hold your baby securely and sway or bounce to music.
Promotes coordination and bonding.

Play Ball

Roll a soft ball toward your baby and let them reach for it.
Great for hand-eye coordination.

Final Thoughts for This Stage

This stage of your baby’s life is a whirlwind of discovery.
From mirror play to sing-alongs, every interaction supports development and builds your bond.

Take it slow, enjoy the moments, and explore activities that feel natural for you and your baby.

You’re doing beautifully.

💡When your little one is ready for the next stage, explore our 5-month activity ideas for more developmentally appropriate play.

More Resources for This Age

Calie Herbst

Calie Herbst, Editor-in-Chief of Milwaukee With Kids, has spent over a decade combining her experiences as a parent of three to create a hub for Milwaukee’s family adventures.

Her decade-long teaching career in Milwaukee Public Schools and academic background, including a Master’s in Teaching from Marquette University and dual B.A.s in Sociology and Spanish from the University of Wisconsin – Madison, fuel her passion for inclusive and engaging family content.

Calie is also a recognized voice in local media, contributing to WISN Channel 12 News, WTMJ Wisconsin Morning News, Fox 6’s Real Milwaukee, and B93.3.

Discover more about Calie’s journey and editorial approach on her About Page and Editorial Policy Page.

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