Your baby’s development: milestones from 4 to 6 months

At 4-6 months old, your baby is growing, learning and changing every day. This is a really special time for you both as your baby gets better and better at exploring their environment (time to get baby-proofing) and communicating with you – get ready for that adorable baby babble!

From those first 4-month-old milestones to your 6-month-old baby’s developing skills, learn all about the physical, social and cognitive changes you can expect over the next few months, and get our top tips on supporting them at every smile, tummy roll, and giggle. 

Reviewed by Deborah, an experienced midwife and public health specialist (MPH). Dedicated to evidence-based care, Deborah draws on her clinical expertise to advocate for women and families across the UK maternity system.

From tummy holding their head up to grasping and giggling, let's take a look at those magical 4-month-old milestones. 

One of the biggest 4-month-old milestones your baby will reach is holding their head up straight on their own. You’ll start to notice that your little one can keep their head up during tummy time and hold their head steady while they’re sitting up leaning against you¹, both big physical developmental milestones.

Your baby is also exploring more of the world with their tiny hands. They’re learning to touch their hands together when lying on their back, to play with their fingers, to reach for toys, and to hold them in their hands¹. 

Your baby is also likely to put things in their mouth once they start grasping, so it’s important to keep a close eye on them while they play and move anything they shouldn’t have well out of reach. Here’s a top tip from Seb’s mum ‘I completely underestimated the interest my son would have in objects around him. It’s never too early to baby-proof your home or to find a safe place to keep your glasses out of reach - having replaced two pairs, I speak from experience!’

This is a really rewarding time in your baby’s development as they start to giggle and coo. They’re getting the hang of the basics of communication by looking at someone when they’re speaking and making noises when they stop².

Your baby should be starting to recognise the most important people in their life now, and they might even squeal or smile when they see you¹.

‘Try letting your baby look in the mirror, ’ says Sylvie’s mum, ‘it was so cute to see her expressions as her reflection moved around and smiled as she was smiling - lots of fun.’

What should a 5-month-old be doing when it comes to their key developmental milestones? Let’s explore. 

By 5 months, your baby will probably be starting to blow raspberries and make other funny noises. They might even be experiencing other communication developmental milestones, such as trying to copy your voice (although it’s still a little early for their first words)².

At 5 months old, your baby might also start reaching for objects like toys dangling from the frame of a play mat or reaching for those little toes whilst lying down. They could also start holding smaller objects and looking at them with interest². There’s a lot to learn at 5 months old, after all!

One of the most significant cognitive developmental milestones at 5 months old is that your baby might start to look for things that move out of sight, like a toy that they’ve dropped or you when you’re playing peek-a-boo³. This is called ‘object permanence’, and is the first sign that your baby understands that objects still exist, even when they can’t see them..

Your 6-month-old baby is learning fast! Discover what’s going on for them when it comes to those 6-month-old milestones. 

A big milestone for your 6-month-old baby is learning to roll over from their back onto their front and from their front onto their back⁴. They’ll soon be able to prop themselves up on their hands while they’re on their tummy, too⁵. They’re probably not quite crawling yet, but they might be able to move around a little more during tummy time.

At around 6 months old, your baby might start acting differently towards strangers than they do with you and other people they know well⁶. They might stare, frown, or cry when they see someone they don’t know, or hold up their hands for you to lift them up and give them a cuddle.

Your 6-month-old baby is probably babbling away now, making noises like ‘baba’ and ‘gaga’. They’re also getting into the swing of how conversations work by waiting for you to finish speaking and then making noises back to you².

Your baby’s vision is getting better all the time. At around 6 months old, they’re able to recognise familiar people and objects from a distance. They should also start following things they find interesting with their eyes, like watching a toy move back and forth⁴.

There are plenty of things you can do with your baby to help support their development at 4-6 months old. 

Try these activities with your baby:

• Give your baby plenty of tummy time. Play on the floor together to encourage them to strengthen their muscles and explore their environment⁴.
• Your baby will love playing with toys that are black-and-white, brightly coloured, textured, or noisy. Try placing them just out of reach to encourage your baby to move towards them⁴. ‘Age-appropriate, soft-textured books are great, ’ says Seb’s mum ‘My little boy loved the one with ‘crunchy’ pages - he’d spend lots of time scrunching them between his fingers to hear the sound.’
• Play peek-a-boo to support your baby’s cognitive development⁵. You’d be surprised how many times this will make your little one coo and giggle (you might even get the odd belly laugh).
• Look at picture books together. Looking at the same books regularly is good for familiarity⁶.
• Sing to your baby, especially nursery rhymes with lots of sounds and actions to keep them engaged⁴.

Talking and reading to your baby is really important for their language development. Here are some tips to try:

• Talk to your baby throughout the day about what you’re doing and what you see to support their language development⁶. Whether you’re exercising, cooking, or out with friends, be sure to involve your little one in what’s going on.  
• Go for walks or trips to the park together and talk about what you see⁴. 
• Take it in turns to smile, babble, and blow raspberries to each other to help your baby understand social cues⁶. 
• Read to your baby to help them develop a love of books and reading early on⁴.

It’s important to remember that every baby is different and goes at their own pace, so try not to compare your 4-, 5-, or 6-month-old’s milestones to anyone else’s (or to their siblings’, if you have older children too). 

If you do have concerns about your baby’s development, you can always speak to your GP or health professional. 

While these signs may be nothing to worry about, it’s important that you let your GP or health professional know if:

Your 4-month-old baby²:

• Doesn’t hold eye contact.
• Doesn’t grasp objects in their hands or put them to their mouth.
• Can’t lift their head for short periods during tummy time.
• Doesn’t make sounds.
• Loses any skills they had before.

Your 5-month-old baby²:

• Doesn’t laugh.
• Doesn’t reach out for toys or other objects.
• Loses any skills they had before.

Your 6-month-old baby²:

• Doesn’t hold their head or shoulders up while they’re lying on their tummy or sitting up with support.
• Doesn’t reach out for or grasp toys.
• Doesn’t show interest in looking at toys, touching them, or putting them in their mouth.
• Loses any skills they had before.

It’s a good idea to make some notes before you speak to your doctor so you have all the information they might ask for on hand.

Think about⁵:

• Things your baby does and doesn’t like to do.
• Any new skills they’ve developed since you last spoke to your GP or health professional. 
• Anything your baby does or doesn’t do that you’re worried about.
• Any skills that your baby had that they’ve now lost, and when you first noticed.

Babies usually say their first words at around 12-18 months old, so you’ll likely have a while to wait yet!⁷ But talking and reading to your baby and copying the noises they make are really important at this age to help them develop the skills they’ll need to say their first words.

Most babies start to crawl when they’re 7-10 months old⁸. Right now your baby is building lots of the skills and muscles they’ll need to get on the move, like holding their head up and getting into a crawling position.

Milestones at 5 months old include reaching for toys, making noises like cooing and blowing raspberries, and developing their sense of object permanence (understanding that objects and people still exist even when they can’t see them)^{2, 3}.

Talk to your baby about the things that you do and see together during the day to help their language development⁶. You can also play games like peek-a-boo and support their physical development with lots of tummy time and toys^{4, 5}.