Axkid UP review: a safe, lightweight high-back booster seat for older children

How we tested the Axkid Up high-back booster seat

• Three months of daily use with our five-year-old

• Tested at the second height setting (105-125cm)

• Used on school runs, day trips and longer journeys

• Installed in a family SUV with ISOFIX

• Trialled for independence - child securing seatbelt alone

• Compared against younger sibling (nearly four) who meets height minimum but isn’t ready in practice

I’ve been testing the Axkid Up over the past three months with our eldest child, who turned five in June and currently measures just over 110cm. We set the seat to the second of its three height positions (for children between 105cm and 125cm) to reflect his current stage.

The seat has been used multiple times a day, from routine school runs and local errands to longer weekend drives and family outings, so we’ve had plenty of opportunities to see how it performs in everyday use as well as on extended journeys. One of the most valuable aspects to test was how easily my son could secure his own seatbelt, something he’s now able to do with confidence thanks to the clear design of the belt guides.

We also considered how the seat might suit younger children. Our almost-four-year-old technically meets the minimum height requirement (100cm), but in practice we felt the Axkid Up was still too advanced for him at this stage, which is an important factor for families with children close to the lower age bracket.

Throughout the testing period, I evaluated the Axkid Up against eight key criteria including: performance, quality and durability, ease of use, value for money, safety and stability, ease of folding and unfolding, comfort and storage.

The Axkid Up comes fully assembled with an instruction manual for installation

Axkid Up back booster seat: what’s in the box?

• Fully assembled booster seat

• Instruction manual

• Yellow installation stickers to guide setup steps

During testing, we received the Axkid Up back booster seat, which arrived fully assembled and ready to install straight out of the box. Also included were clear instructions and helpful yellow installation stickers, which correspond directly to the setup steps and make installation more intuitive.

As part of our review package, we were also sent the Axkid Up Footrest and Axkid Up Cup Holder. Both are usually sold separately, but they make useful additions for longer journeys. Other optional accessories like an iPad holder or car window sunshades are also available to purchase directly from Axkid should you wish to customise your seat further.

How easy is the Axkid Up back booster seat to install?

The Axkid Up arrives fully preassembled, so there’s no need to put the seat itself together. Out of the box, it’s ready to go, and installation took me around 30 seconds, exactly as advertised. I was genuinely surprised at how simple it was, particularly as I’ve lost patience in the past with toddler car seats that require fiddly pinching motions to release ISOFIX locks. The clickable ISOFIX arms on the Axkid Up make the process refreshingly straightforward.

The only extra step after installation is fitting the side wings if your child is 126cm or shorter. Our five-year-old, at just over 110cm, still needs these in place, and adding them was quick and simple. For families wanting an additional layer of safety, there’s also a small door cushion that can be attached to the door-facing side wing for extra protection.

The Axkid Up offers exceptional lumbar support and is made with premium, breathable fabric

Axkid Up back booster seat: how does it look?

We tested the Axkid Up in the Nordic Bloom Green colourway, which was a big hit with our five-year-old as green happens to be his favourite colour. Personally, I would have opted for the Beachgrass Beige version to better complement our car’s beige interiors, but it was nice to see a choice of tones that work for both children’s tastes and parents’ preferences.

The overall design is clean and understated - very much in line with the Scandinavian aesthetic Axkid is known for. It strikes a balance between being practical and stylish, without looking bulky or overly childish. This makes it an ideal option for families wanting a booster seat that feels grown-up enough to carry their child from age four right through to 12, while still blending seamlessly into the car’s interior.

The Axkid Up offers adjustable seating height for added safety

Is the Axkid Up back booster seat safe?

Yes - it certainly gives a strong safety performance, combining advanced engineering with thoughtful features that matter in real-life use. The seat structure is exceptionally sturdy without sacrificing comfort. More impressively, Axkid claims that its ProTecBase™ system (a reinforced steel base with integrated support leg designed to stabilise the seat and absorb crash forces) can reduce the force of a crash by up to 25% compared to conventional booster seats.

Because it’s a high-back booster, the Axkid Up uses the vehicle’s seatbelt rather than a built-in harness, so correct belt positioning is crucial. Axkid’s HeightControl™ system allows the entire seat and backrest to be raised, not just the headrest, ensuring the seatbelt sits correctly across your child’s chest and hips. This helps prevent the belt from riding too low or leaving slack, which is particularly important in side impacts or when the car’s built-in safety systems, such as airbags and belt pretensioners, need the occupant to be at the right height to work effectively.

The raisable seat technology alone sets the Axkid Up apart from most other boosters on the market. Traditional high-back boosters, like the Britax Kidfix i-Size, typically only allow the headrest to be adjusted, relying on a fixed seat position and single belt height. By allowing the whole seat to rise, the Axkid Up provides a more tailored and safer fit as your child grows.

In day-to-day use, these features made me feel more confident, especially when my son leaned or shifted - the head height stays reasonably well supported. These design additions are valuable because in many crashes, belt routing, side protection and stability matter more than flashy extras. One minor niggle: I’d like a clip or mechanism to hold the head support more securely against the vehicle seat so it doesn’t drift when the child is climbing in/out. It’s not a dealbreaker, but worth mentioning.

In terms of certification, the Axkid Up is certified up to 50 kg/150cm, which is above many boosters such as the Graco Assure High-Back Booster Seat. This means it meets (or exceeds) the safety test thresholds for children up to the high end of the 'booster' stage. All of this suggests that the Axkid Up is among the safer choices in its class, especially if you set it up correctly and follow the height recommendations.

The Axkid Up has an integrated ISOFIX base

How easy is the Axkid UP back booster seat to use on the ISOFIX base?

I’m not exaggerating when I say this is the easiest car seat I’ve ever installed with an ISOFIX base. As a parent of two close in age, I’ve wrestled with my fair share of bulky car seats and lost more than a few nails in the process. The Axkid Up’s clickable ISOFIX system feels like a genuine game-changer.

Instead of awkwardly pinching two controls at once and stretching across a heavy seat, you can release each ISOFIX arm individually. It’s quick, intuitive and makes installation or removal so much less stressful. Both my husband and my dad have commented on how refreshingly simple it is to use, which says a lot given how fiddly some car seats can be. Honestly, it feels like this should be the standard for all ISOFIX car seats.

The support leg adds extra stability and reassurance, with the familiar green/red toggle indicator to show when it’s securely in place. It’s a small touch, but one that makes the whole setup process feel fool proof.

What is the Axkid UP back booster seat like to use day-to-day?

For the past three months, our eldest has used the Axkid Up on every single journey - from daily school runs and quick shopping trips to longer visits with family. Not once has he complained about comfort, which feels like a win in itself. Thanks to the seat’s lightweight design and raisable base, he has the independence to climb in and out of the car himself and can fasten his seatbelt without help, which has boosted his confidence.

For us as parents, the Axkid Up has been just as easy to live with. It’s the simplest car seat I’ve ever had to remove, and although we don’t often need to move it between cars, the process is so straightforward that even my dad (the children’s grandad) managed to fit it without any instructions when our eldest stayed with him over the summer. That’s largely down to Axkid’s QuickFold feature, which gives clear visibility of the ISOFIX connections and includes a handy carry handle for lifting the seat in and out.

One small caveat is that folding and storing the seat isn’t as seamless if the footrest is attached. Because it prevents the leg from folding flush into the base, it’s worth removing the footrest if you plan to store the seat in a bag, cupboard or car boot between uses or when travelling. Otherwise, for everyday use, it’s a compact, hassle-free booster that genuinely fits into family life with minimal effort.

How comfortable is the Axkid UP back booster seat

Very! Our eldest has been perfectly content using the Axkid Up on daily journeys. The seat provides strong support without feeling restrictive, which has helped him feel both secure and grown-up.

From a comfort perspective, there are several standout features:

• ErgoSupport lumbar support, inspired by Swedish school furniture, which encourages healthy posture on both short and long trips

• Ventilation holes in the backrest to prevent overheating, especially useful during summer car journeys

• Three seat height positions (100-105cm, 105-125cm and 126-150cm) to ensure the belt sits correctly across the chest and hips while also optimising positioning for the car’s airbags

• Removable side wings, which provide extra protection and comfort until your child is taller than 126cm.

Adjusting the height is very straightforward: simply lift the seat cushion, raise the grey lid and squeeze the control to slide it into one of the three positions. It takes only a few seconds and doesn’t require removing the seat from the car.

It’s worth noting that the Axkid Up is a forward-facing fixed booster seat (other Axkid car seats like the Axkid Minikid 4 Max and Axkid ONE 3 are extended rear-facing), so unlike some convertible car seats, there’s no recline function. Instead, it’s designed to work seamlessly with your car’s existing seat structure, which makes it compact, practical, and well suited for everyday family use.

The Axkid Up folds for easy carrying and storage

Does the back booster seat easily fit in the back of your car?

Given we have an SUV, it fits very easily in our back seat on both sides. My dad drives a saloon and it fits in there with ease, and my mum drives a small five-door hatchback and it fits in there comfortably too. Thanks to how easy it is to remove and install, swapping the seat between ours and the grandparents' cars is no longer a huge chore that ignites arguments. 

The car seat’s QuickFold system makes it very portable and easy to stash while you’re travelling, or when switching between vehicles. But remember to remove that footrest otherwise the leg won’t sit flush in the base. 

Axkid Up accessories are available to purchase separately

Does the Axkid UP back booster seat come with any accessories?

At £399, you might hope a seat of this calibre would include accessories, but most extras are sold separately. As mentioned, during testing, we tried the footrest and cup holder, both of which are useful additions for comfort and convenience on longer journeys.

Other optional accessories include a travel bag, which would be particularly handy for travelling by plane or storing the seat between uses. While it’s slightly disappointing that these extras aren’t included in the base price, they do allow families to customise the seat to their own needs.

Is the Axkid UP back booster seat easy to clean?

During testing, we only needed to wash the covers once, thanks to a dropped McDonald’s ketchup pot. Thankfully, the seat cover is fully removable and machine washable at 30°C, which made cleaning straightforward and hassle-free.

Underneath, the steel frame feels robust and premium, showing no signs of wear even after months of daily use. Overall, keeping the Axkid Up clean is simple which is a bonus considering children often eat and play with toys (some messier than others) in the car.

Is the AXkid UP back booster seat good value for money?

At £399, the Axkid Up is definitely a big-ticket item, but I think it’s worth it if you’re looking for a seat that will last. It’s designed to grow with your child from four to 12 years, and the safety features really stand out. The raisable seat ensures the seatbelt sits correctly, the ProTecBase™ steel frame and support leg reduce crash forces, and the removable side impact wings and lumbar support make long journeys more comfortable.

When you think about how it can replace multiple booster seats over the years while keeping your child safe, the price feels a lot more reasonable. For families who care about safety and long-term value, the Axkid Up ticks the boxes. That said, if you’re on a tighter budget, the upfront cost and extra accessories like the footrest and cup holder might feel a bit much.

About the author

Rebecca Roberts is a writer, editor, and content marketing expert hailing from Leeds. Here at Mumsnet, she commissions, writes and edits to bring parents content designed to make life easier. Having birthed two DC just 15 months apart, she knows all too well how stressful it can be trying to find the right pram or car seat to suit your family's needs. She’s also spent countless hours testing a variety of car seats for all age from baby car seats to toddler seats and boosters for older children. So, she's fully invested in finding the best prams and car seats for new and growing families.

Beyond her role as an editor here at Mumsnet, Rebecca can be found balancing life as a working mum of two toddlers and when she’s not at her desk, you’ll likely find her at a local playgroup, in a nearby coffee shop, or walking the dog.