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Best Diono Car Seat Review- The Radian 3RXT [2023]


A car seat is part of any mother’s baby gear checklist, like baby carriers and baby monitors, and it makes sense if it’s part of yours as well. After all, you want your baby to be comfy and safe when you’re on the road, and a car seat helps ensure that.

The Diono Radian 3RXT is one of my favorite convertible car seats of all time. It has a modern design, impressive durability, and tons of safety features. The 3RXT model, in particular, is one of the best Diono car seats I’ve tried.

If you’re thinking of getting it for your little one, here’s everything you need to know so you can decide.

Quick Overview

If you were to ask me to summarize the Diono Radian 3RXT car seat in just a few words, I’d say luxurious, snug, safe, and full of features. It’s one of my favorite models in the high-end convertible car seat range.

The 3RXT model is an upgrade from the now-discontinued Diono Radian RXT. The new model, now made in the USA instead of China, features a new wrap cover, top tether, easy-glide adjuster, and other features I absolutely loved.

It’s much easier to install, and the aesthetic design upgrades make it even more appealing.

Let’s take a closer look at why this convertible car seat is a parent favorite.

Diono Radian 3RXT Car Seat Features

What I love most about the Diono Radian car seat is its sheer amount of features. It really does deserve the high-end price tag it comes with. Here’s why:

Safety Features

As mothers, we always look for safety features when shopping for car seats. Diono car seats never disappoint, as they are known for having tiny details that keep little ones safe in case of an accident.

In fact, the company is so confident in its Diono Radians, they offer a crash exchange program.

Some of the best safety features in this Diono car seat include:


Side impact protection is a vital feature for car seats. After all, anyone can be rear-ended out of nowhere.

The Diono car seat is made from EPS Foam (Expanded Polystyrene) that’s extra shock absorbent. It’s the same material that top-tier safety helmets are made from. So it’s sure to keep your baby insulated from harm in case of accidents.

Heavy Alloy-Steel Frame and Core

The Diono Radian is pretty heavy. I could carry it, of course, but being just under 30 pounds, it’s no diaper bag.

It’s made from a solid steel core and an alloy steel frame, which keep the car seat firmly in place in case of an accident. The EPS foam sides of the car seat are also reinforced with aluminum, adding to the overall weight.

The Diono Radian is strong and secure, favoring safety and side impact protection over portability. For me, that’s what counts.

The extra weight might be frustrating if you constantly move the car seat between vehicles, but it’s an excellent safety feature.

The bottom of the Diono car seat is lined with rubber parts that help it grip your vehicle seat for more stability.

Harness and Tether

The Diono Radian has a five-point harness that works with both the forward-facing position and rear-facing mode. It attaches at the shoulders, at the hips, and between the legs.

There’s also a rear-facing tether for keeping your baby snuggly in place and preventing rebound motion (rebound rotation).

The Diono comes with a patented Safe Stop harness system specially made for forward-facing children under 40 pounds. I couldn’t locate the clip at first, but after checking the manual, I found it near the back of the car seat.

Head Support

The adjustable headrest on the Diono Radian was another nice, comfy addition to the safety features.


The Diono car seat is FAA approved as safe for air travel in case your little one has a flight to catch. The only downside is it’s not the lightest car seat to take with you when traveling.

Convertible Car Seat Modes

The Diono Radian is one of my favorite convertible car seats because it offers three different settings. Over the years, I switched from forward-facing to rear-facing and then the booster mode without buying a new seat.

The Diono Radian covers the entire 10-year period from birth to booster seat. I was skeptical about the high-end price tag at first, but then I realized I was actually saving money in the long run.

Each mode had a height range and maximum weight limits that fit perfectly, so you might want to pay attention to that.

Rear-Facing Mode

The rear-facing mode has a weight range of 5 to 45 pounds and a height range of up to 44 inches. This is usually the safest position for your baby inside a moving vehicle. Most of the time, I left the Diono Radian in the rear-facing position.

Forward-Facing Mode

A few months in, my baby had outgrown the weight limit, and the rear-facing position no longer fit. I had to switch to the front-facing mode. It has a weight limit of 65 pounds and a height range of up to 57 inches.

Booster Mode

Once your child is no longer a baby, you’ll need to switch to a booster seat. Like most booster seats, the Diono Radian has a 50 to 120-pound weight range.

For a secure and comfortable fit, your baby’s shoulders should be around the fourth strap slot of the harness or above it.

Make sure the vehicle seat belt is tightly fastened to the booster seat for extra safety.

Design Features

The 3RXT model was a pleasant upgrade from the old Diono Radian RXT. Here are some of the design features I liked.

Narrow Width

Despite its fancy features, the Diono Radian convertible seat has a pretty narrow width. Even at the widest point, you could easily fit two more convertible car seats in the back of most mid-size vehicles.

I only had two car seats for my babies, but it’s nice to know a third could easily fit in my car. Whether rear-facing or in booster mode, the seats line up snugly and securely side by side.

When I’m not using the car seat, I would just fold it into a tiny, compact shape that doesn’t take up much space.

There’s also a detachable cup holder on the side that you can remove if you’re tight on space.

Plush Fabric

I absolutely loved the plush fabric covers. They’re soft and cozy but still have a sleek look.

The Diono car seat comes in five different fabric colors, but I personally prefer Jet Black. It’s just more practical for something that’ll last ten years.

The fabric cover is also washable. Word of advice: stick to a gentle cold-wash cycle and use mild detergent if you want the fabric to last. Then let it air dry because dryers can damage the fabric.

If anything were to happen to the fabric or the car seat, Diono has an assortment of replacement covers and spare parts. The replacement covers are expensive, almost a third or so of the seat price, but it beats buying a new seat.

Ease of Installation

Diono seats come with a patented SuperLatch system that makes it easier to install the car seat. The SuperLatch connects the lower anchors of the car seat to your vehicle seat.

It wasn’t clear how to use the SuperLatch connectors at first, but once I took a look at the installation guide and the Diono YouTube channel, it took seconds.

Once you feed the seat belt through the lap belt path and adjust the harness, you’re good to go.


  • One of the safest car seats on the market
  • A convertible, all-in-one car seat that works from birth to booster
  • SuperLatch System for easy installation
  • Steel core, alloy-steel frame, and shock absorbent EPS for side impact protection
  • Memory foam padding and an infant insert for a comfy, cushioned fit
  • The narrow build allows three car seats installation side by side in most vehicles


  • While the extra weight is a safety feature, it can be frustrating if you constantly move your car seat between vehicles
  • You have to manually rethread the straps to adjust the car seat height
  • Relatively expensive, but so are most convertible seats

What’s in the Box?

The Diono Radian 3RXT comes with everything you need to install the car seat right away. Here’s what you can expect in the box:

  • The car seat
  • An infant insert cushion for newborns
  • A cup holder
  • The Safe Stop harness (near the back of the car seat)
  • The rear-facing tether connector strap
  • Owner’s manual

Diono Radian 3RXT Models

After gaining popularity, Diono released another upgrade to the already near-perfect 3RXT model. They called it the 3RXT SafePlus.

There really isn’t much difference between the two models in terms of design and functionality. The SafePlus just has three notable new features.

For example, the SafePlus has a steel anti-rebound bar with anti-slip harness pads. These reduce rebound rotation by up to 50%. They’re mainly for extended rear-facing travel.

The SafePlus still has an adjustable headrest, but it’s equipped with a button to move it up and down. The older 3RXT model had to be manually adjusted, which never really bothered me much.

The only notable difference in the SafePlus is the added raised walls with six layers of reinforced steel and aluminum. So, it offers more protection from all three sides of the car seat.

But one problem with the raised walls is they can obscure the little one’s view. Your child might not be able to see over the car seat, and we all know how cranky that can make them.

All in all, both Diono car seats are excellent choices, and there’s very little difference between them, so it’s up to your preference.

Who is the Diono Radian 3RXT Most Suitable For?

Convertible seats cover a wide range of weights and ages. This Diono car seat is suitable from birth to booster, with a 10-year lifespan.

The extended rear-facing mode is perfect for newborns of up to 45 pounds. It has an infant insert for newborns to provide cushioning and support.

Infants older than two years and up to 65 pounds can use the forward-facing setting.

The booster mode is perfect for children weighing 50 to 120 pounds.

[Related: 9 Best Car Seats for 3-Year-Olds]

Is the Diono Radian 3RXT Car Seat Worth It?

All in all, the Diono Radian 3RXT is an excellent car seat that both parents and babies love. It’s worth the extra buck because of all the fancy safety features and bells and whistles.

With the steel core, secure harness mode, and extra padding, it’s your baby’s own little fortress.

The Diono car seat seems expensive, but it’ll save you money in the long run with its 10-year life span. It grows as your baby grows.

If you can afford the hefty price tag, I’d recommend the Diono Radian or the Nuna Pipa Car Seat.

Wrapping Up

The Diono Radian 3RXT car seat is a solid choice for mothers obsessed with their baby’s safety. It’s one of the best convertible car seats in terms of design, safety features, and comfort.

Try it out for yourself, and see just how much you and your little one fall in love with the Diono.

Jessica Daniels

Hey there! I’m Jessica Daniels, the owner of Posh Tots and a proud mom of two.

Me and my team of experts (who also happen to be moms) test and review parenting products, and share our tips and tricks to help you make informed choices for your little ones.

Let’s navigate this crazy parenting journey together!

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