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Britax Baby-Safe i-Size car seat review

Our rating 
4.4 out of 5 star rating 4.4
User rating
£190.00 RRP

In a nutshell

A roomy iSize-compatible car seat that can be installed with ISOFIX or a seat belt, could last 15 months and be used as part of a travel system
Ease of installing
4.5 out of 5 rating 4.5
4.5 out of 5 rating 4.5
Safety features
5.0 out of 5 rating 5.0
4.0 out of 5 rating 4.0
4.5 out of 5 rating 4.5
Worth the money
4.0 out of 5 rating 4.0
Pros: Conforms to new car seat regulation ECE R129 (i-Size), suitable for babies up to 13kg (15 months), lightweight, machine washable covers, ISOFIX or seat belt, travel system compatible
Cons: Buckle can be fiddly
Skip to view product specifications

The Baby-Safe i-Size is Britax’s first infant carrier that conforms to the new Europe-wide car seat regulation i-Size (the first phase of new law ECE R129).


The seat is designed to provide safety and comfort for newborns up to 15 months, adjusting and protecting your baby as he or she develops and grows to 83 cm in height.

In line with new regulations, the car seat is rearward facing up to 15 months, promotes the use of ISOFIX (although it can be installed in a non i-Size way using a seat belt) and offers increased head and neck protection in the event of a side-impact accident.

The carrier also features Britax’s patented ‘lie-flat technology’, so when you adjust the headrest height the lying position adjusts as well.

This means you don’t have to try to work out the best lying position for your baby because the seat does the deciding for you.

We tested the Baby-Safe i-Size with the ISOFIX Flex base (£150), with our 8-month old Arthur. There is also the Britax Baby-Safe i-Size base, both can be used with i-Size compatible cars and most cars with ISOFIX.  But with the Flex base, the base angle can be adjusted to a flatter position for cars with inclined seats.  Saying that, it’s always best to check which base your car will fit on the Britax Fit Finder website. 

It was obviously reassuring to know the seat conformed to the new regulations, and was therefore designed with the latest research on safety in mind, however for my partner and I what really won us over was how easy the seat was to install, both with and without the ISOFIX base.

Another big plus point for us was the fact the Britax is suitable for babies up to 15 months, or 83 cm in height. Our son is a bit of a bruiser, being on the 97th percentile for weight and height, so I am not sure he will still be able to fit in the seat in seven months’ time, but he has already outgrown the Stokke Izi Go X1 by BeSafe (£205), which is only suitable up to 12 months.

Other i-Size car seats include the Kiddy Evo Luna i-Size (£359.95 including base) and the Joie iAnchor Advance (£169.95)

The Britax Baby-Safe i-Size car seat is available from Kiddicare, Pramworld, and Amazon.

Do you think your son will fit in the seat for the full 15 months?

It’s hard to say. For an average sized baby, I would say definitely yes. Arthur on the other hand is only 8 months old but is already wearing 12-18 month clothes and tipping the scales at 12.5kg, so he is not what I would call a typical 8 month old.

That said, the Britax Baby-Safe i-Size appears far roomier than our previous Maxi Cosi Pebble and Stokke Izi Go car seats. The fact he still fits comfortably in it, with further room to grow, suggests he will be in it for a good few months yet.

Other newborn carseats that comply with the new safety regulations include Maxi Cosi’s Pebble Plus (£190), although again this is only suitable for babies up to 12 months or 75cm, so Arthur would already have outgrown it.

Read what other parents thought of the Britax Baby-Safe i-Size car seat in our MFM Forum product test.

Is it travel system compatible?

Yes. The Britax Baby-Safe i-Size car seat is travel system compatible, so it would be handy for parents who need something that can go from car to pushchair in a single click.

The list of models it is compatible with, however, is not vast. It can be used with any Britax pushchair, as well as a few other brands, such as Babystyle’s Oyster 2 and Oyster Max (adapters required).

It was not compatible with our Quinny Moodd, but since having our second child we never use a travel system, opting instead to put Arthur in his sling while putting his three-year-old brother, Eric, in a lightweight umbrella-style stroller.

If having a travel system is an essential part of your checklist, before investing in the Britax Baby-Safe i-Size you should have a look on the Britax website to see if your buggy is compatible.

How does it install in the car?

Because it has been designed to conform to the new car seat regulation, it uses an ISOFIX base, and this makes inserting the car seat super quick and easy.


But it can also be used with a three point seatbelt, which we found handy as it meant the carrier could be swapped from mine to my partner’s car, without having to keep removing the base. This also helped when we took advantage of taxis over the festive period. Had I needed to use the base as well I think it would have been too much lugging about.

One thing I noticed in particular about installing the seat using the car’s own seatbelts was the size of the groove on the back and the armrests of the carrier that the belts slot through. This was much bigger than the Stokke Izi Go, which has a small round slot at the back and can make installing it quite fiddly.

It is a bugbear of my partner, so to have such a large curved slot on the back of the Britax, with generous slots on the armrests, made the whole process of getting in and out of the car less laborious, and won the Britax a big thumbs up from the other half.

Will it work with cars with short seat belts, do you think?

Our Qashqai has nice long seatbelts, which made installing the seat a doddle. My dad’s Fiesta, however, has much less generous seatbelts in terms of length, but we managed to install the seat in there without much of a problem.

It did mean we had to tilt the chair slightly before clipping it in, but this is the same with any car seat we have tried.

What kind of base will it fit into, how easy is it to slot in?

I have never used an ISOFIX base before and was dreading having to get my head around the kind of complicated instructions which baby products seem to command. I need not have worried; it was foolproof, even for me.

We used the Britax Baby-Safe i-Size Flex base (£150), which is adjustable to four different angles if your car seats are not flat, but there is also the Britax Baby-Safe i-Size base (£130), which doesn’t have this feature.

The leg of the base unfolds by simply lifting it up, and then there is a grey lever underneath which when pulled causes the to pop out.

These are then inserted into the ISOFIX points in your car, with green indicators confirming when the hooks are correctly engaged. Then it was just a swift adjustment of the leg and the seat was ready to pop on. It’s worth noting the carrier would not attach to the base if the indicators are red – if they are not green then you know something somewhere is not as it should be. 


How portable and easy did you find to get in and out of the car?

The seat is relatively lightweight and could be lifted from the ISOFIX base with a simple click, using one hand – easy. It was not a chore removing it when it had been fastened via our cars’ seatbelts, either.

Does it feel sturdy?

The seat itself is relatively lightweight, weighing in at 4.7kg, yet it still packs a punch in terms of strength. It felt sturdy without compromising on comfort, and once installed in the car it felt very secure.

How comfortable is the seat? 

Yes, the five point harness meant Arthur looked more secure than when he was in our Maxi Cosi Pebble, and this also prevented his arms and shoulders from slipping out – a downfall we have experienced with three point harnesses on carseats, pushchairs and highchairs.

The padded headrest meant he also looked very snug when strapped in.

There is a generous amount of padding both on the belts and around the neck. I am guessing this was primarily in fitting with the i-Size regulations that call for extra support, but the added benefit was it provided our baby with additional comfort, and reduced any chance of chafing from the belts.

He is obviously too young to give us his opinion in words, but I would say he looked more comfortable than in his previous carriers.

For smaller babies, the chair comes with a removable newborn insert, adding further comfort and support.

The comfort of the Baby Safe i-Size seat was also highlighted by a few of our mums on our forum, with Rachy87 saying “the car seat is well padded and looks very comfortable but the ultimate test was actually driving her in it. She seemed happy and fell asleep easily. I would give the comfort factor a 100%.”

How is strapping your son in?

It took me a while to get to grips with the buckle, and on a couple of occasions I was left chuntering to myself at the roadside while a wriggly baby did his best to make fastening the buckle nigh-on impossible.

I then realised this was because the straps were too tight, and needed loosening before I buckled Arthur up.

This was an error on my part – I have always adjusted the straps on a car seat to what I felt was the correct length, and then fastened the buckle, but after researching it, I know the safest option is to adjust the straps after baby is buckled up, sliding two fingers under the belt once secure to ensure it is the correct length.

One thing I did miss compared with our Stokke Izi Go was the magnetic strips that hold the straps to the seat while baby is being placed in the seat. I did not realise how useful these were until faced with a seat without them, so I had to remember to place the straps at the side of the Britax before putting Arthur in.


The only other thing that could have made putting Arthur in his seat easier is a swivel base. I imagine this is the case, anyway, as I have never used a carseat with a swivel base, but they do make everything look very easy!

What’s the headrest like?

The headrest was soft yet supportive, and Arthur demonstrated no complaints when he was strapped in. It cushioned his head without squashing it – always a bonus!

Tell us about the integral recline system – how does it work?

The Britax comes with a patented integral recline system, so the position changes automatically when you adjust the headrest. The headrest is adjusted using a lever on the back of seat, meaning the flatness of the lying position changes according to the babies’ height.

What do you think of the design?

It is not what I would describe as sexy, but I have yet to come across a carseat that is! It was clean-looking and functional, and it is clear everything has been designed with safety and practicality in mind. The choice of colours available means you can add a pop of colour to your car if you wish.

What do you think of the size of the car seat? 

We really liked how the car seat could accommodate a larger child than our previous carriers, and it managed this without being large or clumpy.

Is it easy to clean?

The seat was very easy to clean, which I found handy as Arthur has a tendency to bring up the contents of his stomach at the most inopportune times. The covers are easily removed and are machine washable, although I found a quick wipe with a damp cloth managed to get rid of anything my baby, or his brother, managed to throw at it during the time we spent testing it.

How effective is the sun canopy?

The sun canopy was a Godsend for keeping out the pesky rays that winter has a habit of sending our way. It was easy to fold in and out and was also obvious without being in your face.


I make this point because I had been using our Maxi Cosi car seat for seven months before a friend pointed out there was a sun canopy hidden in the top of the seat. When I did finally locate this, I never managed to get it back in again, pretty much in the same way those rain jackets in a pouch never quite go back in the pouch.

The Britax canopy also scored points over the Stokke canopy as I found the latter has a habit of unhooking itself mid-journey, often meaning Arthur’s legs were covered up while his face was in the sun.

What’s in the box?

  • Baby-Safe i-Size car seat
  • User instructions
  • Newborn insert

Is it easy/hard to install the seat into the car?

The seat was simple to fit into our cars using the ISOFIX base, and was also quicker and easier than other models we have tried when using the cars’ own seatbelts to secure it in place. The manual featured the kind of pictorial instructions that are commonplace with many baby products. They were fairly easy to follow, but what we found easiest was watching the videos on the Britax website.

Who would the seat be most useful for?

The seat is ideal for parents who are keen to buy a product that complies with the new safety regulations, and who want their newborn to still fit in the seat beyond the 12 month mark.

Is it good value for money?

Yes, it is!  The car seat on its own has an RRP of £190, but is available from £165, or you can buy the bundle, which comes with complete with the Flex base, for about £300.

This compares to £190 for the Maxi Cosi Pebble Plus, with the two-way fix base setting you back an additional £190 (£380 combined).

And because the Britax seat can accommodate children up to 15 months old, as opposed to 12 months for the Maxi Cosi, £300 seems reasonable value for money.

Additional extras are available for the Britax, namely a raincover (£18), a thermocover (£35) a summer cover (TBC, but probably around £30) and a car seat saver (£18).

We managed perfectly fine without any of these extras, though the raincover would be useful if you were planning to use the seat as part of a travel system, and my partner has suggested the carseat saver would be a wise investment, because he is rather particular about valeting his car.

MadeForMums verdict:

My partner and I really liked the Britax Baby-Safe i-Size car seat – it offered more room to grow than our Stokke Izi Go and nudged ahead of our Maxi Cosi Pebble on account of its secure, five point harness, together with the fact it is suitable for babies up to 83cm.

We would recommend it to parents looking for a car seat that conforms to the latest safety regulations, and who want a car seat that will accommodate their baby beyond their first year.

It was easy to install, both with or without the ISOFIX base, and was comfortable for our 8 month old son. It is a shame Arthur was too old to take advantage of the newborn insert or the lie-flat position of the seat, both of which I feel are big plus points for new babies. 

 We’ve got more car seats…


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Product Specifications


Brand Britax
Model Baby-Safe i-Size car seat
Price £190.00

Suitable for

Child age (approx) Birth to 15 months
Child weight Up to 13kg

Dimensions & Weight

Weight 4.7kg


Car seat installation Isofix base
Travel system compatible Yes
Removeable cover for washing Yes
  • Conforms to i-size ECE R129 regulation


Optional extras Raincover (£18)