Diono Radian 3RXT Review: All-in-one Convertible Car seat

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In today’s Diono Radian 3RXT Review, we aim to give you an unbiased in-depth analysis of the product so you can decide whether this is for you.  

Deciding on which car seat to use for your child can be a daunting task. You need to consider safety, ease of use, comfortability, and whether the seat is suitable for your vehicle.  

There is a lot to consider!

We know that this can be exhaustive for you as a parent. Today, we’ll be examining one of the top car seats in the market, the Diono Radian 3RXT convertible car seat, in an attempt to save them time and effort.

Overall, the Diono Radian 3RXT provides users with high-end security and convenience features.

The Diono Radian 3RXT is one of the best infant car seats along with the Uppababy MESA and Chicco KeyFit 30 in our recommended Narrow Car Seats.

Finally, Amazon has seasonal offers with $50 or 14% off from time to time.

Let’s read on and see if this is what you are looking for. 

Diono Radian 3RXT Review : Image: Amazon
Image: Amazon

Table of Contents

Pros & Cons of the Diono Radian 3RXT


  • Fits 3-across in most vehicles
  • 3 installation modes (Rear-facing, Forward-facing, and booster)
  • Adjustable
  • Fit and comfortable (Cushioned with EPS foam, adjustable headrest and travel high-wedge for newborns)
  • Safe (FAA-approved; No chemically-treated materials)


  • More expensive option than most other infant car seats
  • Narrow harness straps which could pass through the neck instead of a child’s shoulders. 
  • Diono Radian 3RXT weighs 28.1 pounds, which is considered heavy.

What is the Diono Radian 3RXT Convertible Car Seat?

Diono Radian 3RXT Review : Image: Amazon
Image: Amazon

Diono Radian 3RXT is a 3-across all-in-one convertible car seat for babies. It is designed in such a way that it could be used for your child from birth to booster.

Designed to include forward and rear-facing modes, booster mode, and radian 3RXT slim fit structure to enable parents to install 3 separate car seats in a single car to accommodate multiple children. 

Tip: For the rear-facing mode, your baby will be rear-facing and on the back seat, you might consider placing a little car seat mirror to keep an eye on your child while driving

What comes with the Diono Radian 3RXT Convertible Car Seat?

This model comes with an infant support cushion, a cup holder, super latch, adjustable headrest, newborn travel high wedge, rear and forward-facing modes, booster seat conversion for children between 50 – 120 lbs, and a 2-in-1 head and body insert. 

The fabric cover at the back of the seat was designed to add an aesthetic view to the rear-facing mode, However, some parents would prefer a more quality fabric covers for a seat that is supposed to last for 10years.  

Who is Diono Radian 3RXT for?

Diono Radian 3RXT for anyone who wants a smooth driving experience without having to scream at your child every now and then. 

The cushioned convertible seat doesn’t move while turning and your child’s head is held firmly and comfortably against the seat with 12 different recline positions.

Quite expensive and might not be the best option for parents with a tight budget. Diono seats are most compatible with mid-sized vehicles and not small vehicles. 

The rear-facing mode is designed for babies weighing 5 – 50 pounds while the forward-facing mode is for children with a maximum of 65 pounds in weight. The booster seat conversion is designed for older children of 50 – 120 pounds in weight. 

In addition, the Diono Radian 3RXT is ideal for long trips or journeys, because it’s safe, convenient, and can be fastened to the vehicle seat belt so that it won’t tilt or move.

Where to buy it?

In general, Amazon will be a fast and easy option. 

Overall Rating

  • Overall: ⭐⭐⭐⭐⭐(4.7 out of 5)
  • Safety: ⭐⭐⭐⭐⭐
  • Durability: ⭐⭐⭐⭐⭐
  • Ease of Use: ⭐⭐⭐
  • Market Reviews: ⭐⭐⭐⭐⭐
Our evaluation of this product is based on 4 metrics: 1) Safety, 2) Durability and 3) Ease of use, and 4) Market Consensus. We write about each of these metrics in its own section below. 

#1. Safety – How Safe is Diono Radian 3RXT Convertible Car Seat? 

Diono Radian 3RXT Review : Image: Official website
Image: Official website

Total Safety Score = ⭐⭐⭐⭐⭐(4.7 out of 5)

In terms of Safety, we rate the  Diono Radian 3RXT based on the formula below: 

Safety Score = Safety Features + Certifications + Recall/Quality Issues 

Safety Features ⭐⭐⭐⭐⭐

  • Side Impact Protection.
  • High wedge to create a safe and secure lie-flat travel position.
  • Adjustable headrest.
  • Steel core for shield and protection.

In most cases, parents felt their babies were totally safe in this seat. It exceeds all Federal crash testing guidelines. 

EPS foam is installed throughout the seat, this will give your child full protection against shock. 

A very intriguing feature of this seat is the adjustable headrest, it keeps your child’s head firmly placed against the seat and prevents him/her from moving his/her head to see through the window. Your child can comfortably view the outside while on the seat. 

The car seat is not approved for use in aircraft when used in booster mode. Aircraft seats do not have shoulder belts which are required for use with this booster. 

Safety Certifications ⭐⭐⭐⭐⭐

Car: This child restraint system conforms to all applicable Federal Motor Vehicle Safety Standards (FMVSS 213).

Flight: This child restraint is certified for use in aircraft only when in harness mode. Diono and the Federal Aviation Administration (FAA) strongly urge you to secure your child in a child restraint system (CRS) or device for the duration of your flight

Recall/Quality Issues ⭐⭐⭐⭐⭐

At this time, there are no known recalls for Diono Radian 3RXT convertible car seats.

Some quality control issues such as low-quality back seat fabric cover, difficulty in loosening straps, and complicated installation process were discovered by a few parents. 

We also spotted rare reports about the funky smell of the products; this may be due to storage or delivery process issue.

Tips: Keep your receipt. You should examine all sections of the seat as soon as you receive it. The sooner you can reach out to customer support, the better, as they might be slow to respond at times. Be ready to take pictures of the product defects if any. 

#2. Durability: How Long Can You Use Diono Radian Convertible Car Seat?

Diono Radian 3RXT Review : Image: Amazon
Image: Amazon

Total Durability Score = ⭐⭐⭐⭐⭐

In terms of Ease of Use, we rate the Diono Radian 3RXT based on the formula below: 

Durability Score = Range of Use + Expiration + Warranty

Range of Use ⭐⭐⭐⭐⭐

  • Minimum weight limit recommendation is ‎5 pounds (2.3kg) which should be equivalent to a 2-month old baby.
  • Maximum weight limit recommendation is ‎120 pounds (54.4kg) suitable for children between 8 to 10 years of age. Pretty good range.
  • Minimum height limit recommendation is 18.1 Inches (46cm) which is about 2-month-old for a baby. 
  • Maximum height limit recommendation is 57 Inches (144.8cm) suitable for children between 8 to 10 years of age. 
  • Weight range: ‎5 Pounds (2.3kg) – ‎120 Pounds (54.4kg)
For the best use of the car seat, the manufacturer recommends the Range of Use. Exceeding those limits might be okay if you had to. In the end, though, it is about risk, safety, and your child’s comfort.If your baby weighs less than the minimum weight and height limit, you should not put them in the car seat. Additionally, the maximum weight and height limit also tells you if your child has outgrown the car seat, if you can’t already tell or if they aren’t complaining about it.

Expiration ⭐⭐⭐⭐⭐

The Radian 3RXT expires 10 years from the manufacture date. Most car seats have their product life due to the constant wear and tear and hot/cold temperature change with different places you go.

Keep an eye on the expiration date as a safety precaution for your youngster. This information is provided by baby car seat manufacturers depending on the design and materials they employ. Due to the typical predicted wear and tear, car seats that have beyond their expiration dates are more likely to have safety hazards.

Warranty ⭐⭐⭐⭐⭐

1-year warranty from the date of original retail purchase.

#3. Ease of Use: How Will Diono Radian Convertible Car Seat Fit into Your car?

Diono Radian 3RXT Review : Image: Official Website
Image: Official Website

Total Ease of Use Score: ⭐⭐⭐

In short, everything is okay except the car seat is heavy and I wouldn’t want to travel with that. 

In terms of Ease of Use, we rate the Diono Radian car set based on the formula below: 

Ease of use = 

Installation + Adjustability + Maintenance + Carry +Stroller Compatibility

Installation ⭐⭐⭐⭐

Diono Radian 3RXT Review : Image: Amazon
Image: Amazon

NHTSA has not endorsed this car seat for installation, so our review is based on research and from the installation manual. 

There have been a few complaints about the installation process being a little complicated. But Diono advises that you read the user manual of the car seat and the section about child’s safety seats in your vehicle manual before installation.  

The car seat accessories are arranged in the storage at the back of the seat. 

Rear-facing Installation

Here is a video on how to install a Diono Radian 3RXT Rear-facing 

The first thing to do here is to attach the rear-facing base to the bottom of the seat by inserting the tabs into the slots in the seat, ensuring that the base is securely fitted by punching the metal locking tab.

When fastening the seat with the vehicle seat belt, place the seat in a flat position on the vehicle seat and pass the vehicle belt through the rear-facing belt path, buckle it and remove any slack. Pull the shoulder belt until it clicks to lock the retractor and fasten the belt to ensure that the seat is properly installed.

Installing with SuperLatch requires that you first remove the connectors from the storage. Feed the connectors and the adjuster through the rear-facing seat belt path and attach connectors to lower anchors of vehicle seat belts. 

Forward-facing installation

Here is a video on how to install a Diono Radian 3RXT Forward-facing 

Find the top tether and the super latch at the storage at the back of the seat. 

Note that for this installation, you have to lower the adjustable bottom for children weighing 25pounds or more and attach Safe Stop for forward-facing children weighing lower than 4o pounds. 

Route the connector of the top tether to the appropriate vehicle anchor but do not tighten it.  After, ensure the seat is in a flat position on the vehicle seat and pass the seat belt through the forward-facing belt path and buckle it. 

Lock the retractor by pulling the shoulder belt until its stops; push down the seat with one hand and tighten the shoulder belt with the other. Feed the remaining slack into the retractor and then check if the seat has been properly installed. 

Installation with Super latch is pretty easy; remove the connectors and the tether from the storage, place the seat in a flat position and feed the connectors through the forward-facing belt path. Push the connectors through the other side and attach them to the lower anchor of the vehicle seat belt. 

Remove the slack by pulling up the adjuster strap. 

Booster Installation

Here is a video on Diono Radian 3RXT Booster Installation 

Before using the Diono Radian seat as a booster, raise the adjustable bottom by squeezing both metal bars and push-ups, and remove the 5-point harness and crotch buckle per directions in the manual.

Place the seat in a flat position on the vehicle seat and route the shoulder belt through the upper belt guide, route both belts through the lower belt guide and buckle it to and buckle to the seat belts. 

Adjustability ⭐⭐⭐⭐⭐

The infant insert is included for newborns to provide additional padding. The headrest is can be adjusted to one of 12 positions for safety that grows with your child up to 57” / 145 cm talI. The side wings of the seat can also be adjusted for comfort without impacting the safety of your child. 

Adjusting the harness position is also easy with simple steps of buckling and unbuckling.

Furthermore, the Diono Radian 3RXT is FAA Approved for travel with flat, folding design for easy carrying and storing overhead.

This car seat is comfortable and the adjustability features make it great for use even as your child grows older.


The fabric used for the seat cover is aesthetic and just perfect to use and clean. However, some users report that the fabric is thin and quite difficult to remove for cleaning; others simply bought a waterproof seat protector over the fabric. 

Carry-Around ⭐⭐

Diono Radian 3RXT Review : Image: Official website
Image: Official website

With a carrier weight of 28.1lbs, this seat is heavier than average.

Stroller Compatibility ⭐⭐

Diono Radian 3RXT is not stroller compatible. Only meant to be used as a car seat. 

Diono Radian 3RXT Review : Image: Amazon
Image: Amazon

Measures & Specs

  • Seat Weight: 28.1 lb / 12.76 kg
  • Product Height: 28.5 in / 72.4 cm
  • Product Width: 17 in / 43.2 cm
  • Product Depth: 16 in / 40.6 cm
  • Maximum User Height: 57.1 in / 145 cm
  • Number of Head Support Positions: 12
  • Material Type: Alloy Steel, Polypropylene, Plastic, Polystyrene
  • Harness type: ‎5-Point
  • Item Weight: ‎28.1 pounds
  • LATCH connector that makes installation easy

#4. Market Consensus: What others say about Diono Radian 3RXT

Diono Radian 3RXT Review : Image: Official website
Image: Official website

Total Market Consensus ⭐⭐⭐⭐⭐

In terms of Market Consensus, we rate the Diono Radian 3RXT with a 5 star based on the formula below:

Market Consensus =
Customer Feedback (Quantitative) + Expert Reviews (Qualitative)

Customer Reviews ⭐⭐⭐⭐⭐

Overall Rating (4.7 out of 5 based on 2,581 ratings)

Note that for highly-rated products, we will avoid bombarding you with more praises about the product. We intentionally look for substantiated negative reviews or criticisms that add to our knowledge. 

So, if you’re going to jump right into this section, know it has its own merits we’ve discussed before. 

Selected Critical Uppababy Mesa Review

⭐⭐⭐⭐⭐Just having a 3rd child and our largest vehicle being a Honda CR-V, this car seat was a must for fitting all 3 kids ind back seat! It’s the heaviest car seat I’ve ever dealt with but this is your kid’s safety we’re talking about here. Steel frame = confident parents. It’s so much easier for our 2 year old to get in/out of!  – Amazon Review

⭐⭐⭐I love the Diono car seat for the safety, and that I can put 3 side by side, and lastly that it is good for 10 years. However, my order said SKY BLUE…… what happened? My delivered box says Pink Blossom. Good thing I am a childcare provider so it is not simply for a specific boy or girl. Pricey but great car seat, even in the wrong color! – Amazon Review

⭐ In all honesty I expected more from such a high-priced car seat. I have had the seat for 5 months. The cover is tearing apart at the seams. The cover is also falling apart in a few places. It is destroying the rear seats in both my cars. Major bummer. – Amazon Review

Expert Reviews ⭐⭐⭐⭐⭐

Selected Expert Uppababy Mesa Review

“This car seat is made with safety in mind. One mom tells us that she will forever be a believer in this car seat, after seeing how it survived a driver running a red light and T-boning her car — directly into the side where the car seat was fastened. Her entire Chevy Traverse was totaled, but this car seat did not even budge an inch, and it emerged completely without a scratch.” – Healthline

The Diono Radian 3RXT is ranked as one of the best 12 convertible car seats by  Parents.com

“Push-on LATCH connectors with automatic retractors that improve installation Tightness indicator to tell you when the base is installed securely Harness adjustment does not require rethreading The Radian 3RXT has color-coded belt paths designed to ease installation, as well as an easy-adjust harness system. It’s FAA-rated for use on airplanes and folds flat for travel. It also has high safety ratings.” – Parentingpod.com

Conclusion of Diono Radian 3RXT Review

Diono Radian 3RXT Review

We would recommend the Diono Radian 3RXT for your car seat needs. 

It’s one of the best 3-across convertible car seats out there. The Diono Radian 3RXT is safe and comfortable for children and could be used from birth till 10 years after.  In addition to giving you peace of mind, the model’s design and range give you a little more flexibility as your baby grows.

Amazon has seasonal offers of $50 or 14% off from time to time. As of this writing, I can see there is a deal now. So, grab it now if you are interested.

Frequently Asked Questions (FAQs)

Q1. How safe is the Diono Radian 3RXT?

The Diono Radian 3RXT is safe with amazing safety features such as the side impact protection, the EPS foam installed throughout the seat for protection against shock, the high wedge to create a safe and secure lie-flat travel position, and so on.

Q2. Is Diono Radian 3RXT a good car seat?

The Diono Radian car seat is a good car seat that is highly rated amongst the best convertible car seats. 

Q3. How long is the Diono Radian 3RXT car seat good for?

The car seat can be used for a duration of 10 years after the manufacturing date.

Q4. How much does the Diono Radian 3RXT weigh?

This product weighs 28.1 lbs.

Q5. Are Diono car seats approved in Canada?

Yes, Diono car seats are approved in Canada.

Q6. Is Diono Radian 3RXT easy to install?

Yes, Diono Radian 3RXT is pretty easy to install. An installation guide is provided in the manual. 

Q7. Where are Diono car seats made? 

Diono car seats are designed and engineered near Seattle, WA, and manufactured in China.

Q8. What is the height limit for Diono Radian 3RXT? 

The maximum user height for this product is 57.1 in / 145 cm.

Q9. Does Diono Radian 3RXT convert to a backless booster?

This car does not convert into a backless booster seat, however, the head support features will keep your child comfortable. 

Q10. How do I use Diono Radian 3RXT as a booster?

Raise the adjustable bottom by squeezing both metal bars and push-ups, and remove the 5-point harness and crotch buckle per directions in the manual.

Place the seat in a flat position on the vehicle seat and route the shoulder belt through the upper belt guide, route both belts through the lower belt guide and buckle it in. 

Q11. Does the Diono Radian 3RXT recline?

Not really. This car seat has a fixed internal recline angle but with the help of an angle adjuster, you can make the seat more upright.

Q12. How wide is the Diono Radian 3RXT?

The seat is 17 in / 43.2 cm wide.

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Shane is passionate about researching and comparing interesting baby stuff for his baby girl. After getting his Master's in Health Management in London, he worked for a top-tier naming and branding consulting firm based in the US. He helps with the research on this site.