The Best Narrow Booster Seat for Your Four-Year-Old

$$ — Graco Tranzitions 3 In 1 Harness Booster Seat ~ 15.17 pounds - Best transitional car seat, with a three-in-one design. It includes top safety features and a LATCH installation process for more stability and safety during the ride. Also, the non-rethread harness adds more convenience for parents. But, too pricey. Suitable for: 22-100 pounds kids.

$ — GoFit Backless Booster Car Seat ~ 5 pounds - Best for double-foam padding for more stability and security of your kiddo. The seat also offers a complete ventilation process due to breathable and comfortable materials. It meets all safety rules. Still, it has a higher price. Suitable for: 40-110 pounds children.

$ — BubbleBum Inflatable Booster Car Seat ~ 0.9375 pounds - Most portable and compact, space-saving car seat. It's durable and sturdy enough for more robust use, with enduring materials and overall content for wear and tear. It is obliging to all USA and European safety standards. Yet, it has only two seat belt clips. Suitable for: 40-100 pounds kiddos.

$ — Cosco Topside Backless Booster Car Seat ~ 2.2 pounds - One of the most comfortable models, with extra-plush content, necessary for the child's full support, more stability, and comfort when using it. Portable and adjustable for numerous vehicles. However, it is only hand washed. Suitable for: 40-100 pounds kids.

$ — Big Kid LX High Back Booster ~ 7.04 pounds - The narrowest transitional booster car seat with two modes of use. It fits three across. Also, the booster features side-impact protection with an energy-absorbing layer to keep your baby safe. Nonetheless, it lacks LATCH installation. Suitable for: 40-110 pounds children.

$$ — Diono Everett NXT High Back Booster ~ 11.1 pounds - Extremely lightweight, with a slim-fit design, so it saves space in your car. You can find the proper body posture for your kid, thanks to 8 different headrest positions. And the LATC connectors keep it fixed. Nevertheless, it's too expensive. Suitable for: 40-120 pounds children.

$$ — Maxi-Cosi RodiFix Booster Car Seat ~ 16.57 pounds - Most advanced, improved, and integrated design. The seat offers the ultimate comfort with the front-access recline system and twelve different headrest positions. And, the Air Protect technology offers complete side-impact protection. But, again, it's costly. Suitable for: 40-120 pounds kiddos.

$ — hiccapop UberBoost Inflatable Booster Car Seat ~ 1.3 pounds - Best functionality and portability thanks to the design. You can take it everywhere as it's the most compact and convenient for carrying around. More stability due to the non-skid bottom and content. Still, it deflates quickly. Suitable for: 40-110 pounds kids.

$ — Cosco Highback 2-in-1 Booster Car Seat ~ 10 pounds - Maximum safety and comfort due to the harness and seat belt system. Additional stability and better balance due to LATCH attachments. Easy to clean and maintain. Yet, not fitting three across. Suitable for: 40-80 kids.

$$$ — Peg Perego Viaggio Flex 120 Infant Toddler Car Seat ~ 14.8 pounds - Best for adjusting and flexible technology, moving all parts independently. Adds more comfort and keeps your child secure for an extended time. Long-lasting and sturdy for more robust use. However, it is difficult to clean. Suitable for: 40-120 pounds kiddos.

$ — KidsEmbrace High-Back Booster Car Seat ~ 11.43 pounds - Follows your kid's growth and development, offering different adjustable positions and different modes of use. It creates more space for your kids for softness and coziness. Nonetheless, it has specific material quality issues. Suitable for: 40-100 pounds children.

$$ — mifold hifold fit-and-fold Highback Booster Seat ~ 10 pounds - Best versatility and flexibility with more than 200 adjustable settings. Superior side-impact protection due to EPE content. Nevertheless, it offers a shorter seating area. Suitable for: 40-100 pounds kids.

#1. Graco Tranzitions 3 In 1 Harness Booster - Top Pick Convertible Booster Seat

The first booster seat is the best convertible car seat for older children you can find. Graco Tranzitions 3 in 1 is an all-encompassing, narrow but super-safe car seat intended for children from 22 to 100 pounds.

Wherever you look for official recommendations, you'll see that the safest way to move your child from a forward-facing seat to a booster is by using a harnessed booster before the belt-positioning one.

This car seat from Graco grows with your child, allowing a smooth transition that maintains the highest level of safety until your child is ready for a seat-belt.

Graco Tranzitions includes the patented SimplySafe Adjust system that allows harness modifications without rethreading. What is more, you can adjust the headrest among eight different positions.

When your child gains over 65 pounds, remove the harness, adjust the headrest and use two belt-positioning loops to convert the seat into a high-back booster.

The best thing about it is that the child still has side-impact protection and proper head support.

Only when your child no longer fits the high-back booster you can remove the back and transform the seat into a no-back booster only 17.4 inches wide.

This car seat is available in a wide variety of colors and two styles.

The first model is the one we talked about, and the second one includes the SnugLock technology that provides even a higher level of safety due to the LATCH system of installation, ProtectPlus technology, and a higher number of headrest positions.

Both models have machine-washable covers and breathable materials for your child's convenience.

To my mind, whichever model you choose, you can't go wrong because they really are the most advanced booster seats on the market that safely follow your child's growth.

#2. Chicco GoFit Backless Booster Car Seat - The Most Optimized No-Back Booster Seat

Since it's the indisputable commercial leader on the car seat market, it would be strange for Chicco not to have a horse in this race.

As always, it's a highly advanced, super-comfortable, and safe seat, yet this time, compactly designed.

What we have here is one upgraded backless booster seat for kids from forty to hundred and ten pounds.

It's ergonomically designed to provide nothing but comfort and safety, even though it has no back support or side impact protection. How so, you may wonder.

The secret lies in an innovative design.

Namely, Chicco GoFit includes contoured double-foam padding that provides support in all the right places. Besides that, it incorporates two armrests, also padded for your child's convenience.

Materials are very pleasant and breathable, allowing normal air circulation, thus preventing excessive sweating and feeling of discomfort in the summer.

If you're taking your child to practice, no problem. Two retractable cup holders come in handy for their water and sports drinks. When you need to fit three across, simply retract them in, and you have the extra space.

The entire booster measures 15 x 17 x 5 inches, being perfect for carpooling and traveling. It's exquisitely portable, especially because it has a built-in handle for effortless carrying.

Like all Chicco seats, this one meets all safety standards too.

However, if you're not hesitant to spend an extra buck, there is an even more advanced version of this seat - the Chicco Go Fit Plus.

The Plus version includes the LATCH system, letting you safely secure the seat and prevent it from slipping off in the case of collision. It's a bit more expensive, but when you think about it, it's the price you pay for your child's safety.

#3. BubbleBum Inflatable Backless Booster - Top Pick Inflatable Booster

Here we have a multiple-award winner and officially the most portable inflatable backless booster seat- The Bubble Bum.

It's an innovative product, taking up minimal space while providing a 100% safe ride to your child.

This backless booster is the perfect solution for families on the go, carpooling, soccer moms, and large families. It's the lightest booster car seat on the market, weighing only 500g and measuring 11 x 4.5 x 11 inches.

BubbleBum is recommended for kids between forty and one hundred pounds, that is, four and eleven years.

The seat is available in a wide palette of colors and designs, so it's pretty easy to find the one that fits your upholstery perfectly.

Although an inflatable booster, this seat is very durable.

It incorporates a material that is similar to the one life vests are made of. It won't rip off easily and wear off quickly, so you can rest assured it won't fail to deliver.

There is another popular inflatable backless booster, the hiccapop. Yet, parents have been complaining about the sudden deflating of the hiccapop booster.

With BubbleBum, even if this happens, there is a layer of memory foam placed to support the structural integrity, even when the seat is deflated.

It's important to mention that this seat has passed rigorous crash testing, both inflated and deflated, plus it meets or exceeds both European and American safety standards.

The only detail that bubblegum could improve is the seat belt clip. There are actually two clips to thread a seat belt through.

If you were in an emergency situation or a collision, it would be hard to unbuckle the child quickly, leading to potential injuries. So, this is something that BubbleBum could upgrade.

#4. Cosco Topside Backless Booster - Extra Plush Narrow Booster Seat

Choosing a narrow car seat doesn't mean compromising comfortability, at least not in the case of the Cosco Topside booster.

This seat is extra-plush, specifically designed to provide comfort and protect your child.

It supports children from 40 to 57 inches tall and between 40 and 100 pounds in weight. This car seat was designed to take up as little space as possible yet still provide all the necessary comfort and protection to your kid. How?

You can notice that the Cosco Topside includes covered armrests, which is unusual for a backless booster, yet Cosco implemented them to increase the convenience of use.

Furthermore, as I already mentioned, the seat features an extra-plush design, which is way more comfortable for kids than the flat car seat.

This is a perfect car seat for families on the go because it weighs very little, so you can easily take it from one car to another.

It's perfect for traveling, taxis, and rent-a-car, when your child is still not ready for a seat belt, so you want to provide that extra height and buckle him/her up correctly.

Cosco made this seat with a seat-safe design.

What this means is that the combination of materials won't harm your car upholstery. Also, the cover of the seat can be washed, yet only manually.

If you're wondering how exactly small this seat is, let me tell you.

It measures only fifteen inches in width, sixteen inches in length, but three inches in height. It's thicker than the memory foam cushions you can buy for adults.

Importantly, Cosco Topside backless booster has been tested to exceed the federal safety standards, so your child will be safe throughout the entire journey.

#5. Evenflo Big Kid LX High Back Booster - The Most Portable High-Back Booster Seat

The next product for today is the narrowest booster seat with back support, coming from Evenflo and measuring only fifteen inches in width.

It's a convertible car seat, transforming from a high-back booster to a backless booster car seat.

The Evenflo Big Kid LX booster seat features a narrow design that fits any vehicle's seat and allows you to fit three across.

It doesn't weigh too much, thus presenting a perfect solution for families on the go, who often change vehicles and need to transport the booster from one car to another.

Just like the other booster seats I reviewed, it accommodates children from forty to a hundred and ten pounds, which is up to 57 inches tall.

As your child grows, you can adjust it between six height positions; plus, the system is so optimized that you can do it one-handedly.

When you decide your child is ready for a seat belt, remove the back support, and transform the Evenflo Big Kid booster into a compact booster seat with no back.

The weight limitations for the backless booster are the same as for the high-back booster.

When it comes to comfort, this seat is incredibly well designed.

It features an energy-absorbing foam liner and thick padding to provide a perfect blend of comfort and safety. Plus, it's contoured and breathable, preventing heat retention.

In addition to this, there are two elastic cup holders, perfect for drinks and snacks, and two belt guides for safe installation and buckling.

This seat is tested for structural integrity, side-impact tested, and crash tested to provide unmatched safety and performance. It's even tested in rollover crashes, so you don't have to worry for a second.

#6. Diono Everett NXT Rigid Latch - The Most Advanced Narrow Booster Seat

Diono, for years, manages to maintain its reputation as one of the most advanced car seat manufacturers.

Innovation is a word Diono engineers are well familiar with, so it's often the case that their car seats feature a lightweight design combined with impeccable safety features. This is definitely the case with Diono Everett NXT.

This belt-positioning booster seat was designed as a slim fit model, perfect for any vehicle seat and very convenient for carpooling as well as traveling.

It weighs 8.9 pounds, so it's not that heavy either, allowing effortless transport from one vehicle to another.

Diono Everett supports children from forty to a hundred and twenty pounds and between thirty-eight and sixty-three inches high. With that in mind, this seat will comfortably accommodate your child for eight years.

Although the seat features a slim-fit design, that doesn't compromise safety or comfortability in any way.

Namely, it has an ergonomic design with thick padding and side-impact protection. You can tell it's high-quality, given that it won the IIHS's best bet booster award.

Another fantastic advantage is the easy-click rigid LATCH connectors that allow effortless installation and stability.

Plus, the back design features a buckle-friendly fit customized for the vehicle's seat belt.

You can rest assured this seat will grow with your child thanks to the eight headrest positions, which allow customized fit and proper impact protection.

Besides being the most expensive commercial booster seat on the market, it's very popular and highly rated. Of course, it's not as expensive as some high-end models, but compared to other seats on this list, it's very pricey.

You can order it in black, blue, red, and plum color, and it looks very elegant, complementing your car upholstery perfectly.

#7. Maxi-Cosi Rodifix Booster - Parent's Favorite Narrow Car Seat

Another slim booster seat you'll find on countless parent forums is definitely the Maxi-Cosi Rodifix car booster.

Now, before we dive deep into details, I'd like to say that this is a bit of a luxurious booster seat, yet incredibly advanced and optimized to provide maximum safety.

First of all, this is a high-back seat option, available in one size, suitable for children between 40 and 120 pounds.

This is the highest weight limit on the market, eliminating the need for premature seat belt use while making sure your child grows safely buckled-up.

Rodifix booster includes a rigid LATCH installation system, allowing a quick, effortless setup.

This is a significant advantage of this seat since most backless boosters and even high-back boosters do not have a LATCH, so they are not as stable as the Rodifix booster is.

To make sure the seat will indeed grow with your child, Maxi Cosi included twelve headrest positions and a front-access recline system.

Thanks to these features, which allow customized fit, you can use a booster such as Rodifix for many years without questioning the safety.

Since I mentioned safety, I'd like to point out that Rodifix booster includes patented Air Protect technology and side-impact protection for unmatched security.

On top of everything, Maxi Cosi Rodifix booster has premium cushioning for superior comfortability and convenient rides.

Also, the covers are removable and machine-washable, so you can make sure the seat is clean at all times.

Finally, the seat supports children up to 57 inches in height, and it's one of the narrowest booster seats on the market, being only 17.75 inches wide.

All in all, If I could choose 1 belt-positioning booster to recommend as the most advanced and convenient, it would be this one.

#8. hiccapop UberBoost Inflatable Booster - The Best Performance

hiccapop is an inflatable backless booster seat for children between four and eleven years, that is forty and one hundred and ten pounds.

Without any dramatization, I can say this is one of the narrowest car seats on the market.

The seat measures 14.5 inches x 14.5 inches x 4.5 inches. Therefore, it's effortless to fit three across the back seat or hiccapop between two regular child restraint systems of any kind.

Why should you buy the hiccapop inflatable booster?

One thing that is indisputably the biggest strength of this booster is the functionality. It's extremely narrow, very easy to install, portable, and great for storage.

It will take a few seconds to inflate the seat and just as many to deflate it. When you no longer need it, fold it down, and put it in your backpack, bag, sack, or suitcase.

Although very lightweight, this booster is made of heavy-duty materials.

Namely, it includes double-thick vinyl, a high-quality zipper, and a cloth cover that is removable and machine-washable. It also incorporates the metal belt loop for all types of 3-point seat belt systems.

In addition to this, the booster has a non-skid bottom, adapted for all sorts of materials: leather, cloth, vinyl, polyester. Therefore, it won't slide off the seat yet won't damage the car upholstery either.

Now, the seat is effortless to inflate. It includes a leak-proof valve adapted for your mouth, so no inflator is needed; you can do it by yourself.

All this is cool, but there's one concern. Is this seat actually designed to fulfill its initial purpose, that is, safety?

Yes, the seat meets or exceeds all federal safety standards. But 3% of the customers on Amazon who bought it reported air-leaking, which leads to sudden deflating.

#9. Cosco Highback 2-in-1 Booster Car Seat - Growing With Your Kids

What's so specific about the Cosco booster car seat? Well, the seat will wow you due to its 2-in-1 design.

Thus, you can place your kids between 22 and 80 pounds, and they can use it in two different modes.

Firstly, the car seat will work as a forward-facing car seat with a 5-point harness for all 22-65 pounds kids and a belt-positioning booster car seat for all kids older and weighing more than that. So, the car seat will highly adjust to your and your children's needs.

In addition, the 2-in-1 booster car seat benefits maximum safety and security standards, so you can rest assured your kids will be safe and sound on the road. 

Namely, the seat includes LATCH attachment points, offering a complete and stable installation process without moving around, even in accidents.

However, the 5-point harness is specific, as you can moderate it and make it tighter or loosen it to fit your children's needs. In addition, you can adjust it from the front and make it more stable for your growing kids.

But, once they outgrow the harness, you can easily remove it and use the seat as the belt-positioning booster. Thus, the seat grows and meets your kids' needs.

You don't have to worry about your children's stability concerning the seat belt system. 

As you will find, the shoulder belt guides will follow your kids' body posture, and you will find two different modes of threading the seat belt to meet your children's height and better fit. So, the shoulder and lap straps will cover their shoulders and lap, as they should be.

Of course, if your little one is messy, you can remove the car seat pad and clean it in a washing machine.

#10. Peg Perego Viaggio Flex 120 Infant Toddler Car Seat - Most Comfortable and Flexible

Next off, the Peg Perego comes from Italy and includes exceptional technology.

As you might observe, the car seat offers the well-known 4D Total Adjust Technology, and you can moderate it in four different ways.

In addition, the four positions are all independent, so you can moderate: the seat, side wings, upper backrest, and headrest as you like. As a result, the parts won't cause inconveniences, and you can fully operate to make them as flexible as possible.

Thanks to the rigid and solid LATCH attachment points, the car seat offers an effortless installation process and security for your baby.

Moreover, you can also tuck it in the seat when you don't use it. In both ways, the seat will be stable for more extended use.

Concerning comfort, the car seat has five different reclining options, regardless of the position of the car's backrest.

Therefore, your little ones will be relaxed, cozy, and soft wherever you go, even for longer distances. There won't be pressure, discomfort, and restrictions. So, they can enjoy it more.

Due to the aluminum-reinforced and robust backrest, the car seat will include additional protection, security, and safety against the whiplash in the case of a front-end and extra protection and stability when in a rear-end car crash.

So, your baby will remain intact and stable inside the car seat.

But that's not all.

Namely, the car seat also offers kinetic pods, helping with moving all external impacts, forces, and pressure away from the car seat. So, your little one stays stable, secure, and intact in a car collision.

You can easily fold it and store it away when you don't use the Peg Perego car seat. Therefore, it allows an effortless transporting and storing process.

#11. KidsEmbrace High-Back Booster Car Seat - Best Adjustable Design and Technology

The following booster car seat is so unique due to its adjustability and comfort.

As you might notice, the Kid'sEmbrace booster car seat offers an effortless transition to a backless booster seat from a highback booster, depending on your kid's needs.

So, it follows their growth and development.

Moreover, the booster car seat is ideal for all kids between 40 and 100 pounds in both modes. If you use it as a highback booster, your kiddos must be at least four years old, between 38 and 57 inches of maximum height.

But, in the backless booster mode, kids must be between 40 and 57 inches tall for trouble-free use.

Concerning the seat belt system, the booster car seat offers a seat belt clip - a shoulder positioning one, and you can effortlessly adjust it to your child's size.

You will also see the belt-positioning clip guide when using it as a backless booster car seat.

In both cases - highback and backless, the booster car seat will provide maximum stability, security, and safety for your little ones. And the seat belt system will adequately cover their body parts, following the safety standards.

So, it won't cover their stomach and neck, but their shoulders and upper thighs, making them safe and sound on the road.

Your kids can find an attached cup holder to place their favorite beverages and snacks inside for more convenience and better comfort during the ride.

So, they can enjoy it more and focus on the road. And, if they make a mess, you can easily clean it.

Finally, it's crucial to mention that the booster car seat meets and exceeds all safety standards and regulations, including FMVSS, NHTSA, IIHS, and other rules and standards, offering more safety and stability during the ride.

#12. mifold hifold fit-and-fold Highback Booster Seat - Best Versatility and Settings

And, as you already know, mifold never lets us down! The same goes this time.

So let's see why you should never skip this car seat when setting off on a car adventure with your little one.

As it offers the well-known "multi-fit" system technology, the travel booster can adjust to 243 different individual settings. This way, it's the world's most famous compact and portable booster car seat.

Its dimensions are ideal, and they support children from 33 to 100 pounds of maximum weight and 36 to 59 inches tall. Thus, the narrow booster car seat is excellent for fitting three across.

All moms will tell you it's fantastic - me included!

Due to its compact yet portable system and the "multi-fold" technology, the mifold portable booster car seat effortlessly and conveniently folds and stores away for traveling, carpooling, storage, and on-the-go family.

In addition, it's a lightweight and compact travel booster and includes a carry strap for better carrying options.

Thanks to its four different adjustable positions - heat width and height, seat and body, the fit-and-fold booster seat ensures optimal and proper seat belt fit as the little ones grow and develop.

Moreover, the booster car seat provides the ultimate comfort since it follows your kids' age and adequate development.

The expanded polyethylene foam absorbs the energy, external pressure, impacts, and forces in the case of a car accident; therefore, your kiddos will be safe and sound. They will remain intact and untouched.

Moreover, all FMVSS and NHTSA safety standards support this statement.

As you will notice, the narrow booster is an ideal car seat since it's worldwide accepted. However, only Taiwan and Australia don't get it, so skip to an alternative if you plan to go there.

Which booster seat is the narrowest?

The narrowest high-back booster seat is one low key model, the Big Kid LX High Back Booster.

The seat is almost as narrow as the compact backless boosters, measuring only fifteen inches in width.

What is the narrowest backless booster seat?

BubbleBum backless booster seat is one ultra- narrow booster seat, the most space-efficient seat on the market, measuring only thirteen inches in width.

What is the skinniest backless booster seat?

The BubbleBum Inflatable Booster Car Seat is the skinniest one, thanks to its proportions, weight, compact and smaller design.

Still, it offers enough space for your kiddo when using it.

Can you put a booster in the middle seat?

Yes, you can. If the middle seat of your vehicle has a lap-positioning and a shoulder belt, you can install the booster seat safely.

Can three booster seats fit in a car?

Yes, if they are narrow enough, there will be enough space and room for the car seats not to occupy each other's territory.

In addition, you can find numerous slim-fit designs, backless boosters, and inflatable models, suitable for three cross and more comfort.

But, if this is not the case, you cannot use the boosters for fitting three across.

It depends on the type of booster.

High-back booster seats usually come with a LATCH installation system, and they should be anchored, while this is not the case with backless boosters.

At what age can a child use a backless booster?

Well, according to NHTSA, all children between 4 and 7 and 8 and 12 years old can use booster car seats.

The only difference is that they must be appropriately restrained in the highback or harness boosters when they're younger or not ready for backless boosters.

Also, if they're not outgrown their forward-facing seats, they cannot use boosters.

What height does a child need to be for a booster seat?

It's hard to determine the exact height, but if you follow the simple rules, your child is ready for a booster when: