Best car seats for 4-year-olds and beyond: tried and tested by parents

Tested by parent tester Jemma: Read our full Maxi-Cosi Kore i-Size review

With child safety being their highest priority on the road, it’s no surprise that Maxi-Cosi have designed the Maxi-Cosi Kore i-Size to comply with the highest and latest i-Size safety standards, making it a trusted reliable choice for your child.

The Maxi-Cosi Kore i-Size car seat is not only sturdy and comfortable, but it also comes with a smart safety feature called SPS Plus (Side Protection System Plus), which offers an extra layer of protection for your child.

It's designed to help minimise the chances of injury by absorbing the force of any impact. Unlike the regular SPS, the SPS Plus has even better impact-absorbing materials added to its side wings. Plus, it's got glass fibre shock absorbers, which means there's a cocoon shell that offers full-body protection on the sides.

As well as boasting top-notch safety credentials, the Kore's sleek design means that it should continue to appeal to your child as they get older. It looks and feels more expensive than it is, and it’s also easy to clean – crucial in a seat that will last for multiple years.

Although we found the ISOFIX connectors stiff to use at first, the Kore is both simple to use and install. Our tester, Jemma, thought it would be very difficult to make a mistake when installing this seat, even in a hurry, as belt routing is generally very intuitive.

Conforming to the new R129 regulations, the only other seat we tested to do this was the much more expensive BeSafe iZi Flex Fix i-Size. Maxi-Cosi's lifetime warranty is also something none of the other manufacturers offer – and is something to bear in mind when considering the car seat's longevity.

While we also tested and liked the Maxi-Cosi Kore Pro i-Size (see our full review below), an updated version of the Kore i-Size, which has additional features and premium bamboo fabrics, we felt the value and the simplicity of the Kore (often a benefit when it comes to car seats) was something not to be ignored.

Read next: The best baby car seats to buy

If you’re looking for a budget-friendly high-back booster that still delivers on safety, the Joie i-Trillo is a strong option. We previously tested the original Joie Trillo and were impressed by how easy it was to install, comfortable it felt for children, and reassuringly solid its safety features were. The i-Trillo builds on that with a few handy upgrades that make it feel more grown-up and adaptable.

Suitable for Group 2/3 (15–36kg, roughly three to 12 years), it’s used forward-facing and installs with your car’s three-point seatbelt, with ISOSAFE connectors to keep it securely in place. The i-Trillo also features side impact protection for the head, body and hips, adding extra reassurance in the event of a side-on collision. Colour-coded belt guides take the guesswork out of fitting, which is particularly useful if you move the seat between cars.

The main downside is that it doesn’t recline much, so it’s not ideal for kids who nap frequently in the car. Even so, as a step up from the original Trillo, it offers a little extra comfort and adjustability while keeping the same solid safety credentials and good value for money.

All told, the i-Trillo is a smart pick for parents after a straightforward, reliable booster seat that will see children through several years of growth.

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Tested by parent tester Lily: Read our full Axkid Minikid 4 Max review

The Axkid Minikid 4 Max is a premium rear-facing car seat that stands out for its safety credentials. It has passed the Swedish Plus Test, widely regarded as the most rigorous crash test in the world, and meets the latest R129 European safety standards. Our parent tester Lily said this gave her real peace of mind, especially with the added side impact protection cushions, which she called “one more step to safeguard your child against any injuries.”

Designed for extended rear-facing use, the Minikid 4 Max supports children up to 125 cm and 36 kg, offering impressive longevity. It uses a seatbelt installation system with tether straps and a support leg—ideal for cars without ISOFIX points, though slightly more fiddly to fit. Lily said, “It’s made of breathable fabrics [and] it feels very comfortable,” and while she found the tether straps a little tricky at first, she praised the step-by-step installation guide.

However, she noted that it might be better suited to larger vehicles: “It’s difficult to take our daughter in and out of it. When she’s in, it feels a little cramped with her knee bent.” She felt a spin mechanism would help in tighter spaces.

By contrast, the Axkid One 2 is an ISOFIX seat that installs in under 30 seconds, which makes it a solid choice for families who want something quicker and easier to fit. It’s also lighter than the Minikid 4 Max and includes thoughtful features like a sliding seat base for adjustable legroom, stepless recline, and an updated headrest design. But with a lower weight limit of 23 kg, it doesn’t offer the same extended rear-facing potential as the Minikid 4 Max.

We also looked at the newer Axkid One 3, which shares the same ISOFIX design but adds some comfort upgrades. Parent tester Laura found it “very comfortable overall” for her three-year-old, who regularly napped in the seat, and she appreciated the ventilation system that kept her daughter cool on longer journeys. She was especially impressed by the recline feature, which adjusts fluidly up to 42 degrees and the generous legroom thanks to the sliding seat mechanism - ideal for taller kids. That said, while both the One 2 and One 3 prioritise ease of use and everyday comfort, the Minikid 4 Max is the better long-term investment for parents looking to rear-face for as long as possible.

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Tested by toddler mum, Laura: Read our full Maxi-Cosi Emerald 360 Pro car seat review

If you’re looking for one car seat that can genuinely do it all, the Maxi-Cosi Emerald 360 Pro is hard to beat. Designed to take your child from birth right through to around 12 years old, it adapts as they grow, starting with a supportive Newborn Inlay, then transitioning through toddler stages, and eventually into a high-back booster seat.

What makes it stand out is how seamlessly it combines that long lifespan with everyday practicality. You can use it rear-facing or forward-facing, and with five recline positions plus a headrest that adjusts across 15 different height settings, it’s easy to tailor the fit as your child grows.

The integrated base also adds to its versatility. Not only does it offer a 360-degree spin, but Maxi-Cosi’s SlideTech feature allows the seat to glide out towards you (up to 17cm from the base) which is a real help when you’re dealing with a wriggly toddler or a tight parking space. As our tester Laura put it, “We love it! The fact this can be used from newborn is also a plus.”

It’s worth noting that, as a fixed ISOFIX seat, it’s designed to stay in the car rather than move between vehicles, and it’s not compatible with travel systems for those early newborn days. But if you’re after a long-term, all-in-one solution that grows with your child and makes daily life easier, the Emerald 360 Pro is a seriously practical investment.

It’s available in three neutral colourways, Authentic Black, Authentic Blue and Authentic Truffle - designed to blend easily into most car interiors. The breathable mesh fabrics and foam layers help keep your child cool and comfortable, while built-in G-CELL side-impact protection and AirProtect safety cushions add an extra layer of reassurance on every journey.

As your child grows, it transitions into a high-back booster seat, where it’s used with the car’s seatbelt, making it a practical and safe long-term option.

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Maxi-Cosi's Kore Pro i-Size has all the safety and comfort of our overall winner, the Maxi-Cosi Kore i-Size, but boasts additional features, including a ClickAssist light. This is an innovative addition that only Maxi-Cosi has introduced so far on the market. 

Our tester and her daughter really enjoyed the fact that her child could buckle in on her own with ease. The light illuminates the seatbelt socket for 30 seconds once a child is in the seat, which helps them to buckle themselves in, even in the dark. The car seat itself is also easy to install into the car, whether you’re using ISOFIX or not.

While the Maxi-Cosi Kore Pro i-Size is competitively priced, it doesn’t compromise on safety. Like all the Maxi-Cosi car seats currently on the market, this model has been rigorously tested for safety according to the R129 regulations, which means it’s had forward, rear, side and rollover testing to ensure it’ll protect your child in all types of impact. It also has superior side protection features built into the car seat.

Glass fibre shock absorbers in the padded wings of the car seat work quickly to disperse the force of an impact away from your child. We also like that the wings aren’t too rigid and have some movement which helps to cocoon your child in the event of an accident.

From a design point of view, this car seat doesn’t disappoint either. In contrast to the regular Kore i-Size, the Kore Pro's covers are made from premium bamboo fabrics to keep your child cool in warmer weather. Plus, it’s slimline design fits well into almost any compatible car, along with other car seats at the back. 

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A breeze to operate in an ISOFIX-ready or seatbelt-only car, the Britax Römer KIDFIX M i-Size is our top pick for ease of use and hassle-free safety.

Effortless to install in both ISOFIX-ready and seatbelt-only vehicles, the KIDFIX M i-Size builds on everything parents loved about previous models – with smarter safety features, a lighter design, and even more practicality.

Designed for hassle-free use, this seat offers a straightforward setup with or without ISOFIX. Helpful indicators guide the seat belt routing for correct installation every time. The ergonomic, easily adjustable headrest and removable, machine-washable covers keep things simple and clean – ideal for busy family life.

Comfort hasn’t been compromised. In fact, with its generously padded seat, spacious design, and ample legroom, the KIDFIX M i-Size is built to grow with your child and keep them comfortable on every journey.

Thanks to its new slimline profile, it’s easier than ever to fit three seats across the back of most vehicles – ideal for growing families. Plus, it meets the latest i-Size safety standards and has received a good ADAC overall rating of 2, giving you added peace of mind.

Standout safety features include the SecureGuard, which helps position the lap belt safely over the pelvic bones to reduce abdominal forces in a frontal collision. The XP-Pad technology, exclusive to Britax Römer, is a padded guide for the seatbelt that helps reduce neck and chest strain by distributing crash forces more evenly.

You’ll also benefit from advanced Side Impact Cushion Technology (SICT) – a detachable, energy-absorbing element that minimises side collision forces by absorbing impact energy before it reaches your child.

A couple of things to consider: at just over 6kg, it’s lighter than many comparable high-back boosters but still not the most portable option if you need to move it frequently between cars. And while the minimalist design helps with fitting multiple seats, some parents may prefer additional padding or features found in more premium-priced models.

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Tested by Mumsnet editor and mum of two, Rebecca Roberts: Read our full Thule Palm review

If you’re after a high-back booster seat that doesn’t take over the entire back seat, the Thule Palm makes a strong case for itself. During testing, it was used weekly in a Ford Fiesta (i.e. the kind of car where chunky seats quickly become a pain), and our tester, Mumsnet editor Rebecca, found it quick to install with ISOFIX connectors and very stable in the car once fitted.

The Thule Palm also gets the “big kid” factor right. Rebecca's four-year-old could climb in and out of the seat and buckle himself up, which helped with independence. At the same time, the intuitive belt routing was reassuring for her as a parent, helping ensure the seatbelt sat correctly across his shoulder and lap every time.

Comfort-wise, this car seat is ideal on both short and long journeys - Rebecca tested it on weekly journeys of up to 40 minutes as well as longer day trips. It has decent padding, breathable fabrics, and enough headrest adjustment (15 positions) to comfortably see a child through the 100 to 150cm stage.

The only real downside is that the seat height isn't adjustable (only the head rest adjusts), and the footrest costs extra. Still, if you need a well-made high-back booster that’s especially friendly to smaller cars (or a grandparent/second car setup), the Thule Palm is a practical, well-designed choice.

The Britax Römer Advansafix Pro i-Size is a comfortable forward-facing-only car seat with a very reasonable price tag. Best of all, you can use it all the way up to 12 years old, making it a great combination child car seat that’s ideal for both babies and older children alike.

With plenty of impressive safety features and a simple installation process that doesn't require an ISOFIX base, the Advansafix is regarded as a durable and reliable car seat that will go the extra mile. This seat can be secured with ISOFIX anchor points and a top tether that goes over the top of the car seat, plus a five-point harness up until your child reaches 18kg. Then, from 18 to 36kg, simply use the ISOFIX and/or a three-point seatbelt to secure your child in place.   

This model is packed with safety features including soft, padded side wings for side impact protection, a SecureGuard that helps to keep the lap belt in an optimal position – over the pelvic bones (once your child has outgrown the five-point harness), and the SICT (Side Impact Cushion Technology) system. In a side collision, the SICT system pushes the child seat in a controlled way, away from the door, and then deforms. In this way, the additional force and impact is dispersed away from your child.

It's worth bearing in mind that the Advansafix is a big, sturdy seat, and can be tricky to take in and out of the car, so it’s not ideal for transferring between vehicles or if you have limited space. 

Unlike most child car seats that only have one upright position, this one has three easy recline, adjustable positions, allowing your child to nap or relax even while strapped in.

Tested by parent tester Kelsey: Read our full Cybex Anoris T2 i-Size car seat review

The Cybex Anoris T i-Size, along with its upgraded version, the Anoris T2, stands out as a top contender in child car seats, especially for long journeys. As the only forward-facing car seat ever tested by ADAC to receive a 'Very Good' safety rating, it’s no surprise that the Anoris T has earned its title as the best child car seat for travel. Although it’s only suitable up to age seven, its exceptional safety features make it a must-consider option.

Cybex claims that the Anoris T’s innovative full-body airbag technology offers up to 50% higher safety levels compared to a typical forward-facing car seat with a harness. In the event of deflation, the airbag forms a C-shape around the safety shield, preventing your child from moving forward and reducing pressure on the tummy area, while also preventing lateral movement. The T2 builds on this with an upgraded full-body airbag integrated into a cushioned impact shield, enhancing overall safety.

Installation is made easy with separate ISOFIX arms that allow you to secure one side at a time, and a simple light-up guide that turns green when correctly installed. The load leg adds another layer of safety by enhancing stability, reducing forward movement, and helping manage crash energy to protect your child’s head, neck, and spine.

Stylish and easy to install, the plush memory foam padding and recline features ensure comfort, though some parents have noted that their children may take a little longer to adjust to the impact shield compared to a traditional harness. The T2 also offers enhanced breathability with all-around air ventilation, making it six times more breathable than its predecessor, and a large retractable sun canopy for added protection against the sun.

The Anoris T2 further enhances convenience with an upgraded one-click impact shield and a fully adjustable headrest for a perfect fit. Its Advanced Linear Side Impact Protection reduces impact forces by up to 20%, transferring them to the seat's energy-absorbing shell. While we recommend children sit in a rear-facing car seat for as long as possible, up to the age of five, the Anoris T2 is an excellent forward-facing alternative, offering a safety level statistically comparable to rear-facing seats.

While we're recommending it as a good car seat for four-year-olds, you can use the Anoris T2 as early as 15 months once your child has outgrown their baby car seat. Overall, we’d say that when it comes to safety and comfort for long journeys, this car seat is a sure-fire winner.

With its reasonable price tag and ultra lightweight design, you might assume that the Joie Traver doesn’t offer the same level of safety as some of the pricier car seats in the 2/3 category. But the truth is, the safety elements of this seat are top quality.

Thanks to the car seat’s Guard Surround Safety features, the Joie Traver has received a ‘Good’ rating of four stars in tests conducted by ADAC, ÖAMTC and TCS. The sturdy side impact panels on the outer shell offer an extra layer of cushioning and protection for your child’s head, body and hips. Although the headrest is solid and secure with extra padding, some reviewers have noted that it’s not overly restrictive and has enough space for natural movement.

Another handy feature is the simple ISOSAFE technology that allows you to connect and lock the car seat to the ISOFIX handles in one swift motion. In comparison to previous Joie models, the Traver has a particularly nice feature which is that the leg base rest can be extended to improve comfort for older children. 

The seat can be set in one of three available positions with the possibility of changing its depth to accommodate larger bodies. The headrest also goes up slightly higher than the Joie I-Trillo model for instance, making it a great long-term investment that won't break the bank.

When it comes to overall design, safety, ease of use and quality materials, this car seat (which is a great budget buy too!) gets a thumbs up from us and Mumsnetters alike. The padded upholstery cover is also easy to remove and clean.

Tested by Mumsnet editor and mum of two, Rebecca Roberts: Read our full Axkid Up review

The Axkid Up isn’t just another booster seat – it’s the first in the world with revolutionary raisable seat technology, designed to grow with your child from around four up to 12 years old (100–150 cm). Our tester, mum of two and Mumsnet editor Becky, put it through its paces with her five-year-old over three months, and found it impressive both in terms of safety and everyday practicality.

With its steel frame, narrow 43.5 cm width, and ProTecBase™ system, the Axkid Up feels exceptionally solid while remaining comfortable. Axkid claims the reinforced base can reduce crash forces by up to 25% compared with conventional boosters. The HeightControl™ system allows the entire seat and backrest to rise, ensuring the seatbelt sits correctly across your child’s chest and hips – a feature that sets it apart from most boosters, which only adjust the headrest. In day-to-day use, Becky found it gave excellent support as her child moved, and the intuitive ISOFIX installation meant the seat was secure without any fiddly setup.

The Axkid Up also scores highly for practicality. It folds compactly for storage or transport, though in Becky’s experience it has stayed permanently in the car due to its convenience. Her child could independently fasten his seatbelt, boosting his confidence and giving her reassurance. While the premium price of £399 – plus extra for the footrest and cup holder – is notable, the combination of durability, safety, and clever design makes it feel like a genuine long-term investment.

Minor niggles are few; a clip to hold the headrest more securely against the vehicle seat would be handy, but it doesn’t detract from the overall performance. Certified up to 50 kg/150 cm, the Axkid Up exceeds many other boosters, including the Graco Assure High-Back, making it one of the safest and most versatile options in its class.