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Best 3-in-1 car seat reviews

Stakes are high when you’re choosing a car seat. As high as they get.

Each year, 325 kids under the age of five are saved by car seats in the US alone (1), while 608 children aged 12 or younger die in car crashes (2).

Diono Radian 3R, 3-in-1 Convertible Rear & Forward Facing Convertible Car Seat, High-Back Booster, 10 Years 1 Car Seat, Slim Design - Fits 3 Across, Gray Slate

It doesn’t help that the car seat marketplace is a hodgepodge. I’ve seen it all over the past few years – from bad knockoffs rising up based on fake reviews to good seats getting lost in the noise.

Today, I’ll take a precise approach, cut through the noise, flush the ‘intruders’ out and make 5 specific recommendations for 3-in-1 car seats that are worth your money.

Best 3 in 1 car seat reviews – my top 5 picks:

ImageBest 3-in-1 car seat reviewsFeaturesPrice
Dino Radian 3R

Dino Radian 3R

  • Reinforced Aluminum sidewalls
  • Steel core
  • Folds flat for transport
Maxi-Cosi Pria 3-in-1

Maxi-Cosi Pria 3-in-1

  • 3-position recline
  • GCell foam side-impact protection
  • All pillows removable and machine-washable
Graco SlimFit All-in-one

Graco SlimFit All-in-one

  • Steel frame
  • SlimFit design
  • 4-angle recline
Graco Nautilus 65 LX

Graco Nautilus 65 LX

  • Includes a backless booster mode
  • No rethread harness
  • Handy harness storage
Disney Baby Grow & Go (Simply Mickey)

Disney Baby Grow & Go (Simply Mickey)

  • One-motion headrest and harness adjustment
  • Harness holders keep it out of the way
  • Three recline positions

1 – Best 3-in-1 car seat overall – Diono Radian 3R

Diono Radian 3R, 3-in-1 Convertible Rear & Forward Facing Convertible Car Seat, High-Back Booster, 10 Years 1 Car Seat, Slim Design - Fits 3 Across, Gray Slate

Diono Radian 3R is one of the top-rated seats by users, and that applies beyond the 3-in-1 category. There are seats with similar user satisfaction numbers but they typically cost much more.

Even in the Radian series, there are seats that cost twice as much as the 3R, an example being the 3QX and 3QXT. In my opinion, the 3R is the top value for money.

Main benefits

Steel core and reinforced sidewalls

There’s comfort in knowing that your precious cargo is protected by steel. The steel core is well known in the industry as one of the most robust safety solutions. The trade-off here is that steel is extra heavy, but that’s a moot point if you’re not re-installing it every day.

It comes as no surprise that it has solid scores in all the crash testing data I looked at, including the head injury criterion (HIC) and g forces.

Diono Radian 3R, 3-in-1 Convertible Rear & Forward Facing Convertible Car Seat, High-Back Booster, 10 Years 1 Car Seat, Slim Design - Fits 3 Across, Gray Slate

The side walls are Aluminium-reinforced with a thick layer of specialty foam that absorbs crash forces and distributes them onto the frame.

Slim fit design

Diono is the original 3-across seat, meaning it’s but to comfortably fit three passengers in the back seat of most cars. It also made my list of the best car seat for small cars.

Comfortable straps

One of the very few seats that addressed the massive issue that is the uncomfortable straps. Diono added generous memory foam pads to prevent the straps from “cutting into” the baby’s neck.

Easy to loosen and tighten the straps

One of the simplest, most user-friendly strap loosening/tightening systems on the market. You just lift the latch under the foam cover at the front of the seat (can’t miss it) pull on the strap at the front of the seat and adjust it.


  • Can be used as a convertible (rear-facing and forward-facing) and booster
  • Steel core and reinforced Aluminum sidewalls
  • Folds flat to make it easier to carry
  • Memory foam pads on the straps
  • Simple installation using Diono’s SuperLATCH system (click in and out, much a car seatbelt)
  • Adjustable side walls of the seat base – you push them aside to make more room
  • The back of the seat features a velcro-attached cover to store the parts you’re not using

What I like about the car seat

I like the close-to-optimal balance between safety, convenience, and price. There are better 3-in-1 seats and there are cheaper, but none of them strikes that balance as well as the Diono 3RX.

It’s the ideal choice for a conservative buyer.

You can see a more detailed review of the Diono Radian here.

2 – Runner-up – Maxi-Cosi Pria 3-in-1 Convertible Car Seat

Maxi-Cosi Pria 3-in-1 Convertible Car Seat, Blackened Pearl

Maxi Cosi boldly claims they introduced the first infant car seat to Europe, back in 1984. I have no reason not to believe they did, but I’m not a sucker for pompous marketing declarations. I’m more interested in how Maxi Cosi’s Pria and Magellan meet the challenges of real-world use.

Main benefits

Generous padding & high-end craftsmanship

Everything about the padding in Maxi Cosi seats feels a peg better than that of the competition – soft to the touch, perfect stitching, and yet firmly robust.

Safety standards

Pria is one of the very few seats out there that’s advertised to “exceed all federal standards.”

Maxi-Cosi Pria 3-in-1 Convertible Car Seat, Blackened Pearl

Not “meet,” not “meet or exceed,” but only “exceed.”

Modern, eye-catching design

The color combos of the Pria stand out even in a market as saturated as convertible car seats. Personally, I love the two-hue orange combo – it just works with the clean gray and never looks “busy.” If you ask me, it’s easily in the Top 3 best-looking car seats out there.


  • Reclines to three positions
  • Harness holders – these make getting your child in and out much easier
  • All pillows are removable and washer and dryer-safe
  • GCell specialty foam side-impact protection (patented ) – protects the head from side-crash impact
  • Simple, 1-click LATCH connectors
  • QuickFit strap adjustments – raises the headrest and harness height automatically
  • Air protect – a patented safety feature that serves as padding in regular use and impact protection in a crash

What I like about it

Maxi Cosi seats are made by the same company that makes Safety 1st seats (Dorel Juvenile) and the two share a safety-above-all approach. The two brands are, however, very different – Maxi Cosi has a no-compromise quality-focused approach while Safety 1st focuses on budget-friendly products.

It’s also the only convertible car seat from a European company on the list, and I love the high-end craftsmanship of Western European brands.

3 – Best all-in-one car seat – Graco SlimFit

Graco SlimFit 3 in 1 Car Seat -Slim & Comfy Design Saves Space in Your Back Seat, Darcie, One Size

Compared to the previous model, the SlimFit 3 is full 3 inches narrower and made of better (softer) fabric. It’s a great alternative to similar car seats from more expensive brands, like Chicco, Britax, or Urgo.

Main benefits


Everything about the design of this Graco is aimed at saving space – from the initial width of under 20 inches to the rotating cup holders that save an extra 10% of space.

No rethread harness adjustment

Simply Safe Adjust Harness System is straightforward – you adjust the headrest and harness in one motion without rethreading the harness. 

Easy care and maintenance with clear instructions

The seat pad can be machine washed (delicate cycle, drip dry), you clean the buckles and the harness using mild soap/wipes and all the metal parts are to be cleaned with mild soap and cool water.

Graco SlimFit 3 in 1 Car Seat -Slim & Comfy Design Saves Space in Your Back Seat, Darcie, One Size

It’s as simple and user-friendly as it gets.


  • SlimFit design easily fits three passengers across in the back seat – in my experience, it’s a great fit for combo settings in a mid-size car or up (like two booster seats plus this)
  • Steel frame (reinforced)
  • Rotating cup holders designed to save even more space
  • No rethread harness
  • The headrest and the harness adjust in one motion
  • 10-position headrest
  • Reclines back (4 angles)
  • Intuitive InRight LATCH – takes about a second or two to attach

What I like about the car seat

In each “What I like” section I try to pinpoint the one quality aspect that stands out with a particular seat. With this Graco, I can’t do that because nothing stands out.

It’s simply a well-rounded convertible car seat that delivers in all quality aspects and does it at a low price point. The current user satisfaction rate of 99% reflects that.

4 – Top budget pick – Graco Nautilus 65 LX 3-in-1 Harness Booster

Graco Nautilus 65 LX 3 in 1 Harness Booster Car Seat, Featuring TrueShield Side Impact Technology

Main benefits

Great bang for your buck

Graco Nautilus 65 is my budget pick among the 3-in-1 seats. The quality is solid, fabrics feel premium and it’s second to none in ease of use.

Robust build and good positioning

If you’re not limited by space, you’ll appreciate the extra heft. It sits a bit lower and further back than most car seats, which means less kicking and a more comfortable ride for the driver and the shotgun seat.


  • Three modes – forward-facing harness, highback, and backless booster
  • No rethread harness
  • Reclines to three positions
  • Convenient harness storage
  • The body-support pads are removable and machine-washable

What I like about it

The price, that’s what I like the most about this Graco.

Graco Nautilus 65 LX 3 in 1 Harness Booster Car Seat, Featuring TrueShield Side Impact Technology

You’ll pay much less and, judging by what I saw in reviews, you have a 90 % chance of being pleased with your purchase – that’s approximately the percentage of people who gave this seat 4 or 5 stars.

5 – Disney Baby Grow & Go 3-in-1 Convertible Car Seat (Simply Mickey)

Disney Baby Grow & Go 3-in-1 Convertible Car Seat, Simply Mickey

Disney baby Simply Micky doesn’t sound like a serious safety seat. I can assure you it is…and then some.

It comes from Safety 1st and with a base square base of 24.5 x 24.25 inches, it’s one of the more substantial car seats I reviewed.

Main benefits

Sizable baby pillows

The body and head pillow are just the right sizes to comfortably use with smaller babies. The comfort-support balance of the pillows is spot on.

Easy maintenance

The fabric parts are machine-washable and dryer safe, which is not unique. The unique part is this – you can remove the fabric without rethreading the harness, which is a massive convenience plus.


  • Generous body and head pillows (removable)
  • Modes: rear-facing infant seat, forward-facing seat, and booster seat
  • QuickFit adjustment – one-motion adjustment of both the harness and the headrest
  • Three recline positions
  • Tether strap hooks to your car’s tether anchor (when using it in forward-facing mode)
  • Harness holders to keep the straps out of the way
  • Built-in cup holders

What I like the most about the car seat

I love the convenience that comes with removing the fabric parts without rethreading the harness.

Choosing a good 3 in 1 car seat

If none of the seats in my top 5 catches your eye or you simply want to understand the research behind the picks, you’ll want to take the time and read the following section. I’ll go over all the key aspects of choosing the best 3 in 1 car seat for your money.

Diono Radian 3R, 3-in-1 Convertible Rear & Forward Facing Convertible Car Seat, High-Back Booster, 10 Years 1 Car Seat, Slim Design - Fits 3 Across, Gray Slate

Before we move on to the features and quality aspects, let me take a moment here to address the confusion surrounding the terminology. You have your convertible seat, 2-in-1, 3-in-1, 4-in-1, all-in-one…it’s a mess.

Untangling the car seat terminology

Part of the fault for the confusion for the mess goes to the manufacturers for using the terms interchangeably and labeling the products differently on different platforms. If the last below sounds like too much, I’ll boil it down in the takeaway under the list.

Let’s dive in head-first:

  1. Convertible car seats can be used as a rear-facing harness and a front-facing harness. Simple.
  2. If the seat is labeled as “3-in-1 convertible” it can be used as a rear and front-facing harness (same as above) but as a high booster seat, too. Kinda simple.
  3. If a seat is 3-in-1 but the not convertible isn’t in the name, it typically means that it can be used as a forward-facing harness, booster seat, and a backless booster
  4. 4-in-1 is a seat that features the same modes as the 3-in-1 and adds a backless booster mode to the list
  5. All-in-one is where most of the confusion stems from. Most of the time, it will be the same as a 3-in-1 convertible (rear and forward-facing harness and a highback booster). However, some of them also include a high back or backless booster mode.

Note: you might also see the term ‘combination’ used for some of the seats- I have a separate guide on top combination car seats here.

Related read: Top-rated infant car seats

Takeaway – what you need to know

If there’s one thing to take away from the list above it’s the fact that not all of these are made for babies. Note that a 3-in-1 that’s not convertible does not have a rear-facing mode. A good example of that is my 4th pick – GRACO Nautilus.

I hope that helps. Hew!

Primary quality aspects of a 3 in 1 car seat

Harnesses and latches, forward and rear-facing, safety standards, steel, and aluminum frames/side impact protection…it gets too much very fast, especially if this is your first time researching the topic.

If this is not your first rodeo, you’re still likely to stumble onto some new and confusing industry lingo.

In the guide below, I’ll try to use simple language to get the pressing points across. I’ll intentionally leave out stuff that won’t make a substantial difference.

Safety of a 3 in 1 seat – looking beyond the word

Safety is a primary factor, along with installation security and convenience of day-to-day use. I don’t see comfort as a primary factor, more on that in a minute.

Maxi-Cosi Pria 3-in-1 Convertible Car Seat, Blackened Pearl

Safety-wise, you’ll want to look for a seat that meets or exceeds the federal safety standards set forth by the NHTSA¹, the two crucial ones being FMVSS 213² and FMVSS 225³.

¹ NHTSA – National Highway Traffic Safety Administration

² FMVSS 213 (Federal Motor Vehicle Safety Standard 213) – governs safety performance and some design areas of child restraint systems up to 80 lbs – including labeling and instructions, crashworthiness, buckle and release pressure, and flammability.

³ FMVSS 225 – defines the location of top tether anchors and strength of lower anchors.

Here’s the catch – to find its way into the market, a car seat MUST meet or exceed these standards, so you’ll see it listed in specs of every seat out there. This means you have to dig deeper.

That’s what I did for this guide:

  1. I look at the structural integrity and design of the safety features
  2. More importantly, whenever possible, I look for crash testing results. I put most gravity on the Head Injury Criterion (HIC) and risk of chest injury (most often related to the harness clip).
  3. I combine those with the day-to-day experiences of parents in the 3 in 1 car seat reviews and make my picks
It’s not in the lingo

I won’t even get into all the “innovative, proprietary safety technology” – each company has them and slaps bombastic names onto them.

I’m not impressed by a Steel-Shell-Force-This-or-That-Whatever. Show me the safety data, or I’ll look for it myself.

Easy to install using both the belt and LATCH

Let me be more precise here – it’s not about being easy to install per se, it’s more about being absolutely sure that you got it right. That’s why stuff that might seem mundane, like clicking sounds when the seat is locked in place, is a big deal.

I might be overzealous when it comes to installation, but I have a good reason.

The estimated percentage of car seats used incorrectly varies from 46% (NHTSA) to 70% (Journal of Pediatrics). That doesn’t mean that 70 % of parents using car seats are reckless – the very fact they have a car seat indicates they’re not.

It’s more about how easy the seat is to install and, more importantly, how good of an indicator it has in place to check whether you did it right. LATCH installation (Lower Anchors and Tethers for Children) is easier and there’s less room for mistakes.

If unsure, get a professional to install the seat. On a side note, that’s what I love about Graco – their approach “buy-our-seat-and-get-out” – their safety technicians (90+ of them) go above and beyond to help and educate parents on proper installation.

If you’re using the seat belt to install, a built-in lock-off makes a massive difference. This guide will help you visualize how to tether the seatbelt through your car seat without having to use a latch system or anchors.

Convenience and day-to-day use of a car seat

This criterion includes:

  1. How easy it is to adjust the harness (tightening & loosening) and if it requires re-harnessing
  2. How easy it is to work the chest clip / is it padded for extra comfort
  3. If the fabric is removable, machine-washable and dryer-friendly
  4. How straightforward are the buckles? Do they pop out or do you need both hands to operate them?

Secondary factors when choosing a car seat

In the section below, I’ll address the factors I think do make a difference but are not show-stoppers, neither in positive or negative terms.

Comfort and materials

I don’t see comfort and material quality as primary factors when choosing a good car seat for three reasons:

  1. There are differences but none of the seats I look at lack comfort to the point of being a deal-breaker.
  2. The seats we look at meet federal standards, which include some major design and craftsmanship guidelines.
  3. Comfort and high-end materials can never make up for a seat lacking in safety, installation, and ease of use. The opposite does happen.

Bottom line – most of the best convertible car seats are using similar PP (Polypropylene) plastic shells, padding materials, and fabric covers. The differences are mainly in the padding thickness area.

To be clear, I’m not saying ignore comfort. I’m saying adjust the gravity you assign to it to how restless your baby is. For most babies, a 100 dollar car seat will be comfortable enough.


Some of the seats feature a compartment or velcroed backs to store the parts you’re not using. It’s a nice-to-have because it makes for a less “busy” look, but it’s not a must-have.

Weight and size

Not including the weight and size as primary factors might seem counterintuitive.

Graco SlimFit 3 in 1 Car Seat -Slim & Comfy Design Saves Space in Your Back Seat, Darcie, One Size

Let me explain myself. Size and weight are crucial, but they’re common sense. There’s little to no room for mistakes here. You look at the weight limits and the outer dimensions and know if a seat is the right fit for you.

It does get more important if you’re driving a small car or have a prematurely born baby- the good news is that I have a separate guide on top-rated seats for small cars here and top car seats for preemies here.

Moving the two to secondary factors is my way to declutter this guide and make things easier. I only did it after analyzing 100 of 3-in1 car seat reviews and concluding that none of the people complaining about car seats mention weight capacity or size.

Takeaways and future updates

The convertible car seat market is dynamic with new arrivals and new versions of the classics hitting the shelves every month.

That’s why keeping the information fresh is just as important as having a good model for rating the seats. I have both systems in place so you can rest assured that what you’re reading is relevant.

So, even if you don’t like any of the top picks, it’s wise to bookmark this page and come back.

Stay smart and safe,



(1) – CDC – child passenger safety

(2) – NHTSA crash stats (PDF)

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