6-9 Month Baby Development: Key Milestones and Changes

Between 6 and 9 months, many babies become much more active, expressive and curious about the world around them. You may notice your baby becoming steadier when sitting, reaching deliberately for objects, making a wider variety of sounds and showing increasingly clear reactions to familiar people.

There can be big differences between babies during these months. One may be focused on moving, while another seems more interested in sounds and social interaction. Some babies crawl during this period and others do not. Developmental milestones are useful reference points, but they should not be treated as a timetable your baby has to follow exactly.

The best way to use milestone guidance is to look at your baby’s overall progress across movement, communication, play and social interaction.

What changes between 6 and 9 months?

The second half of your baby’s first year can bring a noticeable increase in independence.

At around 6 months, babies may still need their hands for support while sitting. By around 9 months, sitting without support and getting into a sitting position independently are among the developmental milestones identified by the US Centers for Disease Control and Prevention.

Over these months, you may notice changes in several areas:

sitting and general body control
reaching, grasping and moving objects between the hands
exploring objects in different ways
babbling and experimenting with sounds
recognising and reacting to familiar people
responding to their name
showing a wider range of facial expressions
becoming interested in simple interactive games
trying different ways to move around

These abilities do not all arrive together. Development tends to build gradually, with plenty of repetition along the way.

Around 6 months: reaching, rolling and making sounds

At around 6 months, many babies are becoming confident explorers.

The CDC lists milestones most babies can do by 6 months across several areas of development. Socially, these include recognising familiar people, laughing and enjoying looking at themselves in a mirror.

Communication is becoming increasingly varied. Babies may take turns making sounds with you, squeal and blow raspberries.

You may also notice your baby deliberately reaching for a toy they want and exploring objects by putting them in their mouth.

Physical milestones at this age include rolling from tummy to back, pushing up with straight arms while on the tummy and leaning on the hands for support while sitting.

These milestones describe what most babies can do by the end of the age period. They are not a requirement for every baby to perform every skill on the exact day they turn 6 months.

Around 7 months: practising new skills

Seven months often involves lots of practice.

A baby who was beginning to sit with support may become steadier. Reaching can become more accurate, and toys may be passed, turned, banged or examined from different angles.

Some babies start experimenting with ways of moving around the floor. Others are happier sitting and reaching for what they can access.

Communication is developing at the same time. Your baby may repeat sounds, react enthusiastically to familiar voices or become particularly interested when you name something they are looking at.

The NHS recommends naming and pointing to things you can both see during the 6 to 12 month period. Looking at books together can also be simple. You do not have to read every word. Talking about the pictures is enough.

There is no need to turn this into a lesson. A few natural exchanges throughout the day provide plenty of opportunities to listen and interact.

Around 8 months: growing curiosity and mobility

By around 8 months, your baby’s desire to explore may become very obvious.

They may reach further, twist around while sitting or try different ways to get towards an interesting object. This increasing mobility can make the world feel much bigger from your baby’s perspective.

It can also mean that objects you previously considered safely out of reach suddenly are not.

This is a useful time to regularly reassess the spaces where your baby plays. The CDC recommends giving babies safe places to explore and keeping medicines, chemicals, cleaning products, sharp items and breakable objects out of reach.

Social awareness may also become more noticeable. Your baby might respond differently to familiar and unfamiliar people or become particularly interested in where you are in the room.

Games involving repetition, such as peekaboo, can become especially appealing as babies become increasingly interested in what happens when people or objects disappear and return.

Around 9 months: sitting, babbling and interacting

By around 9 months, many babies have developed much stronger sitting and hand skills.

CDC physical milestones at 9 months include getting into a sitting position, sitting without support and moving objects from one hand to the other.

Thinking and play are developing too. Your baby may look for an object that has dropped out of sight or enjoy banging two objects together.

Communication can sound much more speech-like even though your baby is not yet having conversations. The CDC lists making repeated sounds such as “mamamama” and “bababababa” among 9-month communication milestones. Babies may also lift their arms to show they want to be picked up.

Socially, your baby may look when you call their name, react when you leave and smile or laugh during peekaboo. Some babies become shy, clingy or wary around unfamiliar people.

These changes are all signs that your baby is becoming increasingly aware of people, patterns and what is happening around them.

Does a baby need to crawl by 9 months?

No. Crawling is not included on the CDC’s current 9-month developmental milestone checklist.

Some babies may crawl around this stage, but others find different ways to move or begin crawling later. NHS children’s health guidance also describes crawling at around 9 months as something a baby may do, rather than a skill every baby must have achieved.

It is more useful to pay attention to your baby’s overall movement and progress than to focus on crawling as a compulsory milestone.

If you are concerned about how your baby moves, including whether they use both sides of their body similarly, discuss it with your health visitor or GP.

How communication develops from 6 to 9 months

Your baby may not be saying recognisable words yet, but communication is becoming increasingly sophisticated.

Babbling can contain repeated strings of sounds. Your baby may also use their voice, body, facial expressions and gestures to get your attention.

The NHS recommends talking about things you can both see, pointing and naming objects, sharing books and using words alongside gestures during the 6 to 12 month period.

Try following your baby’s attention. If they are staring at the family cat, you might name the cat. If they are holding a ball, you can say “ball” and talk briefly about what they are doing with it.

Simple repetition helps babies hear the same words in meaningful situations.

You can also respond to their babbling. A pause after your baby makes a sound gives them an opportunity to experience the back-and-forth rhythm of communication.

Social development can become particularly noticeable during this stage.

At 6 months, recognising familiar people is among the CDC’s milestones. By 9 months, babies may react when a caregiver leaves, respond to their name and show several different facial expressions.

You may also notice caution around unfamiliar people. The CDC includes being shy, clingy or fearful around strangers among the social and emotional milestones most babies demonstrate by 9 months.

This does not mean every baby will respond to unfamiliar people in exactly the same way. Temperament matters too.

Give your baby time to observe new situations and people. There is no need to force interaction if they seem uncertain.

Fine motor skills and exploring with the hands

The change in what babies can do with their hands between 6 and 9 months can be fascinating to watch.

At 6 months, reaching to grab a wanted toy is among the CDC’s milestones. By 9 months, babies may transfer objects from one hand to the other and bang two objects together.

These seemingly simple actions involve coordination, attention and learning.

Offer safe, age-appropriate objects that your baby can hold and explore. They may turn them around, shake them, drop them repeatedly or put them in their mouth.

That repeated dropping can be tiring for the adult picking things up, but your baby is exploring what happens when they let go. The CDC specifically suggests returning a dropped toy as a simple way to introduce cause and effect.

Supporting development through everyday play

You do not need specialist developmental toys or a packed activity schedule.

At this age, simple interaction and safe opportunities to explore can offer plenty.

You might:

talk about objects your baby is looking at
share picture books and name what you see
copy and respond to their sounds
play simple games such as peekaboo
offer safe objects with different shapes and textures to explore
give your baby safe floor space to move and practise physical skills
hide a toy partly under a cloth and see if they look for it
respond to their expressions, sounds and gestures

The NHS emphasises chatting, playing and reading together during the 6 to 12 month period.

You do not have to entertain your baby continuously. Independent exploration while safely supervised is valuable too.

What if my baby seems ahead or behind?

It is easy to compare babies during this stage because new skills can be so visible.

One baby might sit confidently while another is constantly babbling. Someone else’s baby may be crawling while yours has no interest in moving that way.

A single comparison rarely tells you much about overall development.

The CDC defines developmental milestones as things most children, around 75% or more, can do by a certain age. Milestone checklists can help you notice your baby’s progress, but they are not substitutes for formal developmental screening.

If your baby was born more than three weeks prematurely, the CDC advises using corrected age when following its milestone checklists. Your baby’s health visitor or healthcare team can explain how corrected age applies to your child.

When to get professional advice

Speak to your health visitor, GP or another qualified healthcare professional if you are worried about your baby’s movement, communication, hearing, vision, social interaction or general development.

The CDC advises acting early if your child is not meeting one or more milestones, has lost skills they previously had or if you have other developmental concerns. You can ask a healthcare professional about developmental screening and whether further assessment is appropriate.

You do not need to wait until your baby reaches a particular birthday before raising a concern.

Online milestone guides are useful for understanding typical development, but they cannot assess an individual child. If something about your baby’s development worries you, professional advice is the right next step.