Baby Milestones by Week: Complete Development Timeline

The first year is a masterclass in exponential learning. Your baby starts as a sleeping, eating, crying miracle who can't hold up their own head — and finishes as a walking, babbling, opinion-having small human who can point at what they want and share a snack with the cat.

This timeline covers the milestones most parents care about, in the order they usually appear, with the honest ranges. Two universal truths up front. First, ranges are wide, and your baby's timing is theirs. Second, watching for pattern matters more than watching for exact weeks — a baby who is doing lots of preparatory skills (pushing up, reaching, babbling) is a baby who is developing, even if a specific milestone hasn't landed yet.

This is educational content, not medical advice or a diagnostic checklist. Your pediatrician tracks your baby's development at well-child visits — please raise any concern there rather than in Google search. We're the team behind Vyve, a private on-device AI wellness tracker for women, men and seniors, with tools that can help you log baby milestones without giving anything to ad networks.

How to think about milestones

Milestones fall into five broad domains:

• Gross motor — big movements: head control, rolling, sitting, crawling, walking.
• Fine motor — hand skills: grasping, reaching, pincer grasp, self-feeding.
• Language and communication — cooing, babbling, first words, understanding.
• Cognitive — problem-solving, object permanence, cause and effect.
• Social and emotional — smiling, engagement, stranger awareness, attachment.

Babies often surge in one domain while pausing in another. A baby working on walking may pause on new words. A baby babbling nonstop may not roll for another few weeks. Both are normal.

Weeks 0–6: the newborn window

• Reflexive smiles (not "at" you) and grimaces.
• Fists clenched most of the time.
• Turns head to sounds by around 2 weeks; recognizes your voice.
• Focuses on faces 8–12 inches away.
• Feeds every 2–3 hours.
• Sleeps 14–17 hours (in bits — nowhere near through the night).
• Newborn reflexes: Moro (startle), rooting, sucking, grasp, stepping.
• Cries — a lot. Peak "crying" around 6–8 weeks.

Tummy time can start from day one — a few minutes at a time, working up gradually. It sets the foundation for everything ahead.

Months 2–4: the awakening

• Social smiles in response to you — the moment.
• Coos, gurgles, vowel sounds.
• Follows moving objects with eyes.
• Lifts head during tummy time (45 degrees at 2 months, 90 by 3–4).
• Grasps toys placed in hand; brings hands to mouth.
• Longer awake windows.
• Starts to sleep in longer stretches at night (some babies).
• May roll — but usually a bit later.

Months 4–6: rolling and reaching

• Rolling — tummy to back around 4 months, back to tummy around 5–6 months.
• Reaches deliberately for toys.
• Grasps and holds objects; puts everything in their mouth.
• Head control fully established.
• Sits with support; some sit briefly unsupported near 6 months.
• Laughs and squeals.
• Babbles start: "ba-ba," "ma-ma," "da-da" (not yet "meaning" you).
• Recognizes familiar faces and shows distress with strangers as this window closes.
• Starting solid foods usually happens around 6 months (per your pediatrician).

Months 6–9: sitting and scooting

• Sits unsupported reliably (6–8 months).
• Rocks on hands and knees; may army-crawl or scoot.
• Transfers toys hand to hand.
• Solid food journey continues — new textures, self-feeding attempts.
• Pincer grasp (thumb + finger) develops toward the end of this window.
• Object permanence starts to emerge — peek-a-boo becomes hilarious.
• Stranger anxiety often peaks.
• Sleep may regress temporarily — 8-month sleep regression is real.
• Babbling gets more varied and conversational-sounding.

Months 9–12: crawling and cruising

• Crawling (traditional or otherwise) is well underway.
• Pulls to stand using furniture (9–12 months).
• Cruises along furniture (10–12 months).
• First independent steps for some (9–15 months is the wide-normal range).
• Pincer grasp refined; picks up small objects.
• First real words — with meaning — start emerging.
• Waves bye-bye, points, imitates.
• Follows simple commands ("give me the ball").
• Feeds themselves with fingers; drinks from a cup with help.
• Strong attachment to primary caregivers.

Around the first birthday

Around 12 months, many babies are:

• Cruising or taking first steps.
• Saying 1–3 meaningful words.
• Understanding many more words than they can say.
• Pointing at things they want.
• Playing simple games (peek-a-boo, patty-cake).
• Enjoying being read to (short books with clear images).
• Getting a well-child check with vaccinations.

By the second half of year one and into year two, walking, running, and vocabulary explosion happen at wildly different paces per child. Ranges keep widening.

Red flags to raise with your pediatrician

These aren't diagnoses. They're prompts to bring up at a checkup.

• No social smile by 3 months.
• No head control by 4 months.
• Not reaching for objects by 5 months.
• Not rolling in either direction by 7 months.
• Not sitting with support by 9 months.
• Not babbling by 9 months.
• Not responding to name by 12 months.
• No pointing, waving or gestures by 12 months.
• No words by 15 months.
• Not walking by 18 months.
• Loss of any skill they had — at any age. This is the most important red flag.

How Vyve helps

Vyve is our on-device AI wellness tracker for women, men and seniors. Its family features include a simple milestone log with age ranges built in, a note-taking space for observations, and a summary you can print or share with your pediatrician. Everything stays on your device — no cloud accounts required, no ad networks. Your baby's information is nobody else's business.

Frequently asked questions

When do babies smile?

Reflexive smiles start in the first weeks. True social smiles — the ones in response to your face or voice — typically appear between 6 and 8 weeks. If your baby isn't smiling socially by around 3 months, mention it at their next pediatric checkup.

When do babies roll over?

Most babies roll from tummy to back around 4 months, and back to tummy around 6 months, though the order and timing vary a lot. Once rolling starts, safe sleep gets even more important — always place baby on their back to sleep, and if they roll during sleep, that's okay by that point but keep the sleep space bare.

When do babies start to crawl?

Crawling typically appears between 7 and 10 months, though some babies skip crawling entirely and go straight to pulling up and walking. Both patterns are normal. What matters more is the underlying strength and coordination — pushing up during tummy time, pivoting on their belly, getting into hands-and-knees position — not the specific way they get around.

When do babies say their first word?

First real words (used meaningfully) typically appear between 10 and 14 months, though the range is wide. Babbling with consonants ("ba-ba," "da-da") usually starts around 6 months. By their first birthday, most babies say one or two words and understand many more. If your baby isn't babbling by 9 months or has no words at 15 months, mention it at their checkup.

What are baby developmental red flags?

Common red flags to discuss with your pediatrician include: no social smile by 3 months, no head control by 4 months, not reaching for objects by 5 months, no babbling by 9 months, not responding to their name by 12 months, no words by 15 months, or loss of previously acquired skills at any age. Ranges are wide and slight differences are usually normal, but persistent gaps deserve professional evaluation.