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Best Diono Car Seat – 7 Car Seats Compared

Looking for the best Diono car seat? Here we compare 7 of the top models based on their features and longevity for your child.

If you have been wondering what is the best Diono car seat for your family, you are not alone. With so many great options from the brand (a lot of which sound quite similar!), deciding which car seat to buy can be rather hard. That’s why we prepared this guide to help you out. 

This guide will outline all the best Diono car seat models and what makes them stand out. It will also highlight the pros and cons of each one to help you make the best choice for your little one. 

Let’s dive right in, shall we? 

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Who is the Diono car seat brand?

Before we get to the car seats, let’s first find out who the Diono car seat brand is and what makes them tick. 

Diono is an American company based in Seattle. The company brings more than 20 years of American design and engineering experience to the table for the specialized design of their car seats.

Founded in 1999, the company has a passion for problem-solving and safe family travel. This has allowed it to provide multiple groundbreaking safety solutions in the car seat industry. 

What makes Diono car seats stand out is the fact that they are built for safety first. All of them come with reinforced steel core frames. They also have side impact protection that comes from 8 interlocking layers of steel, plastic, and eps foam. 

Best Diono Car Seat

For this guide, we compared all Diono car seats, including Diono’s Radian Series (3R, 3RX, 3RXT, 3QX, and 3QXT), Diono Monterey, and Diono Everett. Here are the results: 

Car Seat NameCan be front facing?Can be rear facing?Can it be used as a booster?Weight restrictions?Can it be used 3 across?
Diono 3RYESYESYES5-50lb rear facing;
22-65lb forward facing;
40-120lb booster mode
Diono 3RXYESYESYES5-50lb rear facing;
22-65lb forward facing;
40-120lb booster mode
Diono 3RXTYESYESYES5-50lb rear facing;
22-65lb forward facing;
40-120lb booster mode
Diono 3QXNOYESYES4-50lb rear facing;
40-120lb booster mode
Diono 3QXTYESYESYES4-50lb rear facing;
22-65lb forward facing;
40-120lb booster mode
Diono MontereyNONOYES40-120lb booster modeNO
Diono EverettNONOYES40-120lb booster modeNO

Pros and Cons of The Diono Car Seat Brand

Here are key takeaways to keep in mind when it comes to Diono car seats:


  • The padding the seats use is very comfortable, which is a lot better than what most standard car seat brands use
  • They are light and super portable
  • The car seats are designed to offer additional side impact protection
  • They have firm, high-quality, and secure seat belts
  • The slim fit design means you can comfortably fit at least 3 of them in the back seat of a small car
  • The car seats are also designed to be quite high and narrow as well, which means if you have a taller child, you can keep using the seats for longer
  • Most have removable covers for easy care
  • Generally easy installation with a seat belt, lower anchors and/or top tether


  • Diono car seats can be rather pricey
  • Some of their models do not work well in the rear-facing position, leading to an awkward fit
  • Not all of the models are FAA approved (according to our research these models are: Rainier, Olympia, Radian RXT, Radian 3R Series, Radian 3Q Series, convertible car seats) – please double check on the side or back of your seat before attempting to take it on a flight
  • These models are not made in the USA
  • They have varying weight limits so be sure to check your seat
  • They do not all work for both front-facing installations or rear-facing installations
  • Not all come with an infant insert
  • They do use flame retardants – according to the Diono website, “Diono car seat fabrics are tested to ensure they do not contain any legally restricted, harmful flame retardants, however, in order to meet Federal and Canadian Motor Vehicle Safety Standards for flammability, Diono’s car seat fabrics do contain flame retardants.”

Diono 3R – Most Affordable/Best for 3 Across

What makes it unique?

The Diono 3R was designed to be an all-in-one convertible car seat. It is the car seat design that made Diono as popular as it is today. It is also the most affordable convertible seat option on this list. 

The frame of the 3R is made using strong integrated steel. The padding is made of memory foam, which makes it very comfortable for your little one.

It has a uniquely narrow design that allows up to 3 car seats to be comfortably lined up next to each other in the backseat. This means if you have triplets, this is the perfect solution for you!

The beauty of this car seat is that it will grow with your little one right from birth to childhood. It can be used in a rear-facing position, forward-facing mode, and booster mode. 


  • It has a narrow design, allowing it to easily fit three across in most cars
  • It is very compact
  • A convertible seat that can also serve as a booster
  • It folds down easily for ease of storage
  • Super easy to install with a simple click installation process
  • It comes with 5 shoulder and 3 buckle positions
  • It has an expandable footrest and a non-slip rubber base


  • The strap design is rather difficult to manipulate
  • It has fewer safety features than higher-end models on this list

Diono 3RX

What makes it unique?

The Diono 3RX stands out because it comes packed with lots of Diono’s signature innovative features. It utilizes the company’s slim-fit design, which means you can fit up to 3 of these bad boys in your car’s back seat.

This is is also an all-in-one car seat, meaning you can use it as an infant car seat, in front-facing and rear-facing modes, and as a booster seat. It works perfectly across 5 to 120lbs so your little one will be able to keep using it until she is not so little anymore! 

Additionally, the Diono 3RX features a 12-position adjustable headrest. This gives you more options for your child’s comfort. You’ll love the steel alloy frame and the fact that it is rated for use for 10 years, making it the only car seat you ever have to buy! 


  • It uses Diono’s slim-fit design that makes it possible to fit three across in most cars
  • The headrest can be adjusted through 12 different positions
  • It comes with a steel alloy frame for extra safety
  • It folds down easily for ease of storage
  • Super easy to install with a simple click installation process
  • It has extended rear facing up to 50lbs
  • The headrest contains extra padding for extra support and comfort


  • It is expensive
  • Some people find it quite heavy

Diono 3RXT – Award Winning Car Seat

What makes it unique?

The Diono Radian 3RXT is designed to protect your little one from the time she weighs only 5lbs to when she’s 120lbs. It’s a lifer!

This all-in-one convertible car seat can seamlessly transform from an infant seat to a booster seat and be used in both rear and front-facing modes. It is the only car seat you’ll ever need to buy, because it will grow with your child, serving you well for at least 10 years. 

The 3RXT features a steel core insider for added safety and durability. It is also built slim, which means you can install up to 3 Diono Radian 3RXTs in your back seat and your little ones will be comfortable in them. A great choice if you are a mom or dad of multiples! 


  • It is rated to serve you for at least 10 years
  • 12 positions easy-adjust headrest
  • Super easy to install with a simple click installation process
  • Has a set of firm, high-quality, and secure seat belts
  • It has a slim profile that makes it possible to install up to 3 seats in the back seat
  • It folds flat for space-saving efficiency when you travel


  • The fabric is not removable. In case of a mess, you have to spot clean
  • It is a little heavy because of the steel core

Diono 3QX

What makes it unique?

This 4-in-1 car seat is foldable to make storage an easy and convenient process. It is also designed to be extra safe and comfortable for your little one. While its bulky design may not be for everyone, it makes up for it with great usability (up to 10 years!) and a high weight limit (up to 120 pounds). 

You’ll also love the safety features it comes with, such as the 6 layers of side impact protection, an anti-rebound bar, and a lot of extra padding. It also folds down flat for convenient storage when you travel. 


  • It is an extremely comfortable vehicle seat, with lots of padding 
  • Comes with a lot of safety features such as extra rear-facing protection and an anti-rebound bar
  • It folds flat for travel
  • Has a set of firm, high-quality, and secure seat belts
  • It is more affordable than the 3QXT
  • It has a slim profile that makes it possible to install up to 3 seats in the back seat


  • Installation can be time-consuming
  • It is rather heavy because of the steel frame
  • It is almost as expensive as the 3QXT but misses some features that the 3QXT has


What makes it unique?

The Diono 3QXT is the flagship car seat of the Diono lineup. It features a high-quality steel core and frame, an anti-rebound bar, along with a host of other safety features. You’ll also love the impressive rear-facing weight limit, which can support up to 120 pounds! 

It comes with a 12-position headrest. This allows you to adjust it to meet your little one’s needs. It is also the secret behind this vehicle seat’s ability to adjust from rear-facing to forward-facing to booster mode with ease. 

It is very convenient to install with an easy click installation that gets it done in a snap. Plus, because it is so slim, you can install two more of these in the backseat without any problems.

Many parents also love the fact that this car seat’s fabric cover is completely removable and machine washable: exactly what you need when your little one inevitably creates a mess! 


  • Super easy to install with a simple click installation process
  • It has a slim profile that makes it possible to install up to 3 seats in the backseat
  • It has a 12-position headrest that allows you to adjust it for your child’s comfort
  • It comes with a 4-stage newborn protection package (newborn head and neck insert, a traveling wedge for angling your newborn, a position liner, and harness pads)
  • It folds flat for space-saving efficiency when you travel


  • It is not a cheap car seat
  • When you try to install more than one 3QXT at the same time, installation becomes challenging


What makes it unique?

The Diono Monterey is a great choice for long car rides because it is designed to keep your little one cool and relaxed. It comes in a lot of lovely color options and has an easy-to-install LATCH system that makes it very easy to use. 

Your little one will adore this car seat because it comes with armrests and cup holders. The cup holders neatly tuck away until they are needed. It also has a removable seat cover which makes it very easy to clean when your kiddo makes a mess. 

The Diono Monterey has breathable side planets that will keep your little one cool and comfy on long car rides. It also converts to a backless booster so your 10-year-old will still enjoy using it without complaining!


  • Wide and contoured seat
  • It offers height and width adjustability
  • It is easy, fast, and safe to install
  • Lots of bright color options
  • Sturdy and comfortable


  • It is a pricey car seat
  • It is rather heavy because of the steel frame
  • While the vehicle seat cover is machine washable, you have to line dry it to avoid ruining it


What makes it unique?

The Diono Everett is a super lightweight car seat that is made using high-quality memory foam, which makes it a great choice if you want your little one to enjoy the most comfortable rides. It is also the most portable option on this list. 

You’ll love the very generous headrest that is packed with padding to protect your child’s head in the event of an accident. You can also use it in 7 different positions, which is a lot more than what most standard models offer. The Everett comes with a handle at the back that will allow you to adjust it through these positions. 

Additionally, the fabric cover of this car seat is completely removable and machine washable in the washing machine. This will make your life a lot easier every time your child makes a mess! It is a wonderfully ergonomic car seat that is designed to give your little one lots of protection while also guaranteeing comfort. 


  • It is a very light car seat
  • The installation process is fast and easy
  • It is designed to be highly portable to make swapping between vehicles a breeze
  • It relies on ergonomic memory foam to guarantee your little one’s comfort


  • It rattles when not installed correctly, which can be annoying but also can alert you to an improper install

Final Thoughts On Diono Car Seats

Diono is a great choice whether you have younger babies or older kids. They make the perfect car seats for long trips. Plus, you get a lot of versatility with them, with most models having the ability to be used in front-facing, rear-facing, or booster seat mode. 

They are designed for your child’s safety and comfort as well as your convenience and ease of use. Overall, they are some of the safest seats on the market today.

They have a full steel frame and removable covers and are easy to install. Most of them are also designed to fit 3 across in a mid-sized car and come with an anti-rebound bar for even more safety! 

If you have to pick only one model from this list, we highly recommend the Diono 3QXT. It comes with all of Diono’s safety features. It is also very durable and easy to use, and it is designed to maximize your little one’s comfort. What’s not to love?

The best part about Diono car seats is that they are rated for use for up to 10 years or until your child weighs at least 120 pounds. The company is a leading car seat manufacturer that brings a lot to the table, which is why these high-quality car seats are worth every penny! 

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