My Comprehensive Diono Radian 3RXT Review

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All-in-one car seats are really popular these days, since a lot of parents really like the idea of only having to buy one car seat per child. If you’re looking at an all-in-one, then you’ll want to check out the Diono Radian 3RXT Review below.

This convertible car seat is really well designed overall, and I think it would make an excellent choice for a lot of people. That said, there are a couple of drawbacks that you should be aware of before making final decision.

Things To Consider When Buying An All-In-One Convertible Car Seat

There are a number of good all-in-one convertible car seats on the market, and they each come with different benefits and features. Here are a few things to consider when you’re shopping.


At the end of the day, safety is kind of the main point of a car seat. Look for a convertible car seat from a reputable manufacturer that does well in safety tests.

While it can be tempting to save a few dollars by purchasing a used car seat, this is actually one of the products that you will want to buy new. For one thing, car seats come with an expiration date. In addition, it’s fairly hard to tell how much wear and tear has been put on a car seat. In particular, if you end up getting a used one that has been in a collision or two, it might not be fully functional.


When shopping for a convertible car seat, you will want to think about your particular situation. If you have a really large car or SUV and only have one kid, size might not be your most important consideration.

On the other hand, if you want to fit three car seats in the back or you drive a small car, you might want to look at more compact convertible car seats. When trying to fit three in the back, width is the most important factor. If you drive a small car, you will want to consider width, depth and height. If a car seat takes up too much real estate from front to back, it can make front seat travelers feel a little cramped.

Ease Of Installation

Almost all car seats are at least somewhat difficult to install. However, some are easier than others.

If you’re planning to put the car seat into one of your cars and leave it there for a few years, ease of installation probably isn’t your top priority.

On the other hand, if you plan to take your kids on a lot of cross country flights, or switch them back and forth between vehicles, this can have a big impact on your overall experience.

Weight Limits

When you’re looking at all-in-one convertible car seats, you will want to check the weight limits for each mode (rear facing, forward facing, and booster mode).

It’s safest for young children to sit in a rear facing car seat. So, the higher the weight limit in the rear facing position, the better.

You will also want to make sure that the booster weight limit is fairly high. The last thing you want to do is have to buy another booster seat because the one you have tops out at too low a level.

Adjustable Recline

Make sure to look for an all-in-one convertible car seat that is able to recline when rear facing. This will help ensure that your child is happy and comfortable.

What Is A Diono Radian 3RXT?

The Diono Radian 3RXT is an ultra stylish all-in-one convertible car seat. It’s designed to be the only car seat or booster seat that you will ever need to buy for your child since it can function in rear facing, forward facing, and booster mode.

Diono has earned a stellar reputation for making narrow car seats, so that parents can fit three across in the back seat of the car. The Diono Radian 3RXT was built with that in mind. This means it’s well suited for small cars as well.

It’s also worth pointing out that the Diono Radian 3RXT is a high end car seat. So, if affordability is high on your list of priorities, this is probably not the convertible car seat for you.

Diono Radian 3RXT Review

The Diono Radian 3RXT convertible car seat has an innovative design and packs in a lot of features that parents love. It’s also super stylish, which is a nice bonus considering it will be a part of your car for years to come.

Designed With Safety In Mind

The Diono Radian 3RXT car seat is built with a full steel alloy frame, making it quite heavy and solid. That is also what makes it so strong and secure.

Beyond the frame, it comes with aluminum reinforced sidewalls and energy absorbing EPS foam. It also comes with adjustable head support for comfort and protection.

This seat supports children with a five point harness seat belt in rear and forward facing modes. So, they will be well secured. It also comes with a rear facing tether that provides an extra layer of security.

If nothing else, you should feel that your child is safe sitting in Diono’s battle tested Radian 3RXT convertible car seat.

Narrow Width Allows It To Fit Well In Small Spaces

At just 15 inches wide, this convertible car seat fits well in small cars. It’s also possible to fit three across in mid-size vehicles. This is a big benefit for families with three little passengers sitting in the back. Even if you only have one or two convertible car seats in back though, it’s nice to have the extra space for any other passenger or items that need to fit in.

The car seat is 28.5 inches tall and measures 16 inches from the front to the back of the seat. While its width is quite narrow, it actually takes up quite a bit of space from front to back because of the way it sits in the car. This can create issues for the driver or passengers riding in the front seat.

Some parents combat this problem with Diono’s angle adjuster. This elevates the car seat into a more upright position, and provides more room for travelers that are in the front seat.

All-In-One With Extended Rear Facing Capability

Sitting in a rear facing car seat is the safest way for young children to travel. So, it’s worth paying attention to the weight limit for any rear facing car seat.

The Diono Radian 3RXT shines in this area, since it suits rear facing children weighing between 5 and 45 pounds. This is a much higher weight limit than most other convertible car seats.

Kids can sit in forward facing mode if they weigh up to 65 pounds. Beyond that, they can sit in booster mode if they weight between 50 and 120 pounds.

Beyond the different seating modes, this car seat is truly designed to grow with your child. It has memory foam seat padding and infant support cushions that can be removed when appropriate. It also has expandable sides and a long seat bottom that will help your child stay comfortable through toddlerhood and well into childhood.

At the end of the day, this is truly the only car seat you will need to buy.

Middle Of The Road In Terms Of Installation

This car seat can be installed with a lap belt, shoulder belt or a unique SuperLATCH system.

It does have a closed belt path, which makes it a little bit more difficult to install than some other car seats. But, this isn’t too big of a deal.

A lot of car seats can be a huge pain to install. This one isn’t as bad as some others, but it’s also not way up on the easy end of the spectrum. Overall, it’s pretty average in this department.

Makes Air Travel A Breeze

When you travel with your kids, it’s often a good idea to bring a car seat. Yes, you can potentially rent one along with a rental car when you reach your destination. But, bringing your own can save a few dollars and a few headaches.

This convertible car seat can fold flat, making it a lot easier to carry than others. It’s fairly heavy given it’s steel alloy frame. However, it’s a lot less awkward to carry than others when it’s folded.

It’s also FAA certified. So, you can bring it on the plane, and your child can sit comfortably in a familiar seat during the flight.

A Few Other Features

This car seat has an adjustable recline, which should keep your child comfortable.

It has a cup holder as well. While this isn’t overly critical for infants, it does get more and more important as your child grows. The last thing you want to do when you’re driving is to continuously pass a sippy cup back and forth.

On The Expensive Side

This is a well engineered, well built car seat, and it’s priced accordingly. While it’s not the most expensive option out there, it’s closer to the high end of the range than it is to the low end.

Having said that, the very fact that it’s an all-in-one might mean that is saves you money in the long run since you won’t have to buy multiple car seats and boosters.


  • Steel alloy frame makes this solid and safe
  • Narrow width makes it ideal for small cars or fitting three across the back
  • Ultra stylish look
  • All-in-one convertible car seat
  • Extended rear facing capability
  • Travel is a breeze since it folds flat and is FAA certified
  • Adjustable recline
  • Five point harness in rear and forward facing mode


  • On the expensive end of the range
  • Not overly easy to install
  • On the heavy side
  • Take up a lot of space from front to back unless you purchase an angle adjuster

All-In-One Convertible Car Seat Comparison

The Diono Radian 3RXT stacks up pretty well against the competition. Here are some good alternatives though, if you want to check out some others.

Graco Milestone All-In-1 Convertible Car Seat

This one is 17.5 inches wide and 21 inches from front to back. So, it’s a little larger than the Diono Radian 3RXT, but not too much. It comes with rear facing, forward facing, and high back booster modes. It tops out at 40 pounds when rear facing, which is solid by not as good as the Diono Radian 3RXT. Perhaps the biggest benefit with this one is that it’s easy to install. It’s also quite reasonably priced.

Safety 1st Grow And Go 3-In-1 Convertible Car Seat

This is an interesting option, since it’s fairly affordably priced. It is a bit larger than the Diono Radian 3RXT. In particular, it’s 19 inches wide and 24.5 inches from front to back. It comes with rear facing, forward facing, and belt positioning booster modes. The weight limit when rear facing is not quite as high either at 40 pounds, though that’s still pretty good.

Graco 4Ever Extend2Fit Platinum 4-In-1 Car Seat

This one is fairly comparable in price to the Radian 3RXT. It allows for children to remain in the rear facing position up until they weigh 50 pounds, which is even more impressive than the Diono Radian 3RXT. In addition to rear facing and forward facing modes, it offers two different booster options: highback and backless. With a 21.5 inch width and 20 inch depth, it does take up a little more space than the Diono Radian 3RXT. Finally, it gets high marks for easy installation, making it an attractive choice.

Should I Buy A Diono Radian 3RXT?

When you get down to it, this is a safe, well built car seat that will give you peace of mind. It’s an all-in-one, so it truly has the potential to be the only car seat that you ever buy. Oh, and it happens to be super stylish, which is no small thing.

This is a really strong option in cases where space is at a premium. If you have a smaller car or want to fit three car seats in the back, this could be the right choice for you.

There are a lot of great reasons to buy this car seat. The biggest reason not to do so is probably the price. However, given that it’s an all-in-one, you might actually end up saving money in the long term since you won’t have to buy multiple car seats and boosters.

Cristin is a co-founder of Smart Parent Advice, and the loving mother of two wonderful children. In her free time, she can often be found in a yoga studio or catching up on her favorite shows.