We are mom-supported. When you buy through links on our site, we may earn a commission.

Diono Radian 3RXT Convertible Car Seat Review

The Diono Radian 3RXT is one of 13 other Diono car seats and booster seats. The Diono brand has a reputation for modern design, durability, safety and style. The 3RXT meets the standards customers expect from Diono. It is also a top convertible car seat to satisfy parents’ need for reliability and function.

The Diono Radian 3RXT convertible car seat offers luxury, comfort and safety. Plus, it’s one of the few high-quality convertible car seats to fit three seats across most mid-sized vehicles. Overall, the 3RXT is a solid convertible car seat option that’s built to last.

Diono Radian 3RXT Convertible Car Seat, Black

Benefits of the Diono Radian 3RXT

Diono 2019 Radian 3RXT All-in-One Convertible Car Seat (Discontinued by manufacturer)

Convertibility and Compactness

Convertible car seats are a solid investment when you purchase a product that is made with quality to last as your child grows. The Diono 3RXT is literally made of steel, with a steel alloy frame, to hold up in a crash or against daily wear and tear. 

The two best benefits of the 3RXT convertible car seat are the ability to fit three seats across and the longevity of the product. The seat works well for multiples or kids of various ages. For most vehicles, three of the car seats will fit in the multiple positions available – rear-facing, front-facing or booster. It’s a great narrow car seat.

This best convertible car seat is designed to work from birth up to 12 years old making it a good investment for the lifespan of your car seat needs. Also, the 3RXT works rear-facing for up to 45 pounds and 44 inches in length. This means you can keep your child rear-facing for longer. 

Comfort and Color

I also love the comfort of this car seat. Quality fabric covers the seat to make it more aesthetically pleasing and comfortable. The seat has a memory foam seat base to keep your child riding easy. This is great for long hours in the car. 

Another fun benefit with the 3RXT is the great color choices. Sometimes it’s the little things that make a product appealing. With five colors to choose from, you’ll be able to add your personal style to your car seat choice. However, this product lasts so long, the standard black may be the right selection. 

Safety and Installation

The 3RXT is heavy, but you get a solid product that’s built to keep your child safe in a crash. The seat has the SuperLATCH installation features, but still requires a learning curve for proper installation. With the weight and the installation, this product is not easily moved. 

I find the weight and the installation a benefit because it adds to the safety of the product. The 3RXT car seat is best used as a standard seat for your vehicle and not for moving frequently between vehicles.

The Diono 3RXT convertible car seat offers many excellent benefits for parents and children. This products many benefits should make your choice to buy the 3RXT a snap. 

Features and Specifications

Diono 2019 Radian 3RXT All-in-One Convertible Car Seat (Discontinued by manufacturer)

When compared to other convertible car seats, this all-in-one model matches the competition. The modern design, attention to safety and comfortable seat make it stand out from the rest. 

Plus, all of Diono’s car seats include top of the line features. The Diono 3RXT includes the features parents want like a steel frame, latch installation system and five-point harness.

The 3RXT includes head and body support for newborns and works for babies five pounds and up. However, most convertible car seats aren’t an ideal to fit newborns. If a convertible seat is your only option, this will work. But, if you can afford an infant car seat or travel system, the fit will be better. 


  • Integrated steel frame
  • Contains energy absorbing EPS foam for safety and comfort
  • SuperLATCH installation
  • Patented Safe Stop harness system
  • Includes rear-facing tether 
  • Available in five color options: black, gray, blue, red and pink


  • Weighs 28 pounds
  • Product dimensions: 16.1 x 16.9 x 28.4 inches
  • Rear-facing from 5 to 45 pounds
  • Forward-facing with 5 point harness up to 65 pounds
  • Booster seat conversion for 50 to 120 pounds

Parent Approved

Parents overwhelmingly approve of the Diono Radian 3RXT all-in-one convertible car seat. The combination of top-rated safety and riding comfort appeal to parents. 

The 3RXT does cost more than some other convertible car seat models. However, it is made with a steel base, memory foam seat and quality fabric. This product is built to last. It also works from birth to 12 years old. In other words, it’s worth every penny.

Safety is the entire point when selecting a car seat. Several parents report this car seat protected their children in deadly crashes. Even without all the other bells and whistles, the safety features make this car seat a great choice. 

In fact, Diono is award-winning for design and safety. From the cool color choices to the FAA approval for air travel, the 3RXT offers versatility. If you do plan to travel with this heavier car seat, the Diono Car Seat Travel Bag makes transport easier through the airport.

For an added benefit, consider purchasing the Diono Ultra Max Seat Protector Mat. These mats save your seats from food and beverage spills, not to mention sick kids and potty accidents. 

Parents love the Diono 3RXT, which supports the recommendation for this convertible car seat.

Areas for Improvement

Diono 2019 Radian 3RXT All-in-One Convertible Car Seat (Discontinued by manufacturer)

Is it Worth the Weight?

Weighing around 25 pounds, the Diono 3RXT is rather heavy. Depending on your needs this may be good or bad. If you need to move your car seat frequently, weight might be an issue. 

However, the 3RXT weighs a lot because it has a steel frame. This means added safety in the event of a crash. It also means this car seat is durable. Durability is good in a car seat that is designed to work until your child is 12 years old. 

Overall, if weight is an issue you may want to opt for a lightweight car seat option. But, if safety is your top priority, the steel frame and top safety features of the 3RXT are hard to beat.

Does Ease of Installation Matter?

Like with weight, ease of installation depends on how you plan to use the car seat. If you want to move the seat frequently, or if you want to use the car seat as an infant carrier, another choice may work for you. 

The Diono 3RXT uses the SuperLATCH technology and rear-facing tether. The back of the seat has a fabric cover which makes installation more challenging. 

Also, each of the three positions require a different procedure for installation. The instruction manual is available online for easy access, but this car seat will not work well for you if you don’t have the patience to learn the installation process.

Overall, this seat is best used as a stationary seat in your primary vehicle. Choose another seat for your secondary vehicle or for frequently moving between vehicles. 

Also, some individuals found three seats do not fit in a vehicle’s third row. While this may be true, Diono recommends not using this car seat in the third row. 

How it Ranks Against Other Convertible Car Seats

The Diono brand isn’t as popular as some other car seat brands like Graco or Britax. This Seattle-based company is known for products with solid construction and modern design. I think this brand will continue to grow in popularity.

Diono vs Graco

The 3RXT compares to the Graco 4Ever 4-in-1 convertible car seat for similarity of features and functions. Both car seats work for children between five pounds and 120 pounds. Also, both should last for 10 years of use.

Graco is a reliable brand and both products are equal in function. However, I like the Diono 3RXT better for its style and compact design. The color options, modern flare and overall look of the product ranks better than the traditional Graco style. 

Also, the top convertible car seat options all fall in a similar price range. If you plan to use the car seat daily, stick with the better quality brands. While you can find cheaper convertible car seat options, the purpose of a convertible seat is to last through many growth stages. Invest in a product that lasts. 

Diono stacks up well against the competition. Your personal style and design preferences are good decision points when comparing these similar brands.

Final Verdict

Diono 2019 Radian 3RXT All-in-One Convertible Car Seat (Discontinued by manufacturer)

For families looking for a convertible car seat, the Diono Radian 3RXT is a solid choice. While it has a few negatives, like being on the heavier side, not the snuggest fit for newborns and learning curve for installation, the benefits outweigh any negatives. 

I truly believe this car seat will hold up in safety and quality. It should be the only convertible car seat you will need. However, do remember that any car seat in a crash should be replaced. 

With all that said, if I wanted a convertible car seat, I would buy this product. It is well made, safe and designed with style and function in mind. But, I never preferred a convertible car seat for my children. Instead, I liked to buy a seat for each stage. 

While I do recommend the Diono 3RXT, for newborns and infants under six months of age, I believe an infant car seat is best to ensure safety and comfort. My top pick for infant car seat is the Chicco KeyFit 30 Infant Car Seat. It is available as a stand alone product or part of the Chicco Travel System

Overall, the Diono 3RXT is a great choice for convertible car seat. You can feel confident purchasing this product for your child. It is sturdy, safe and looks great!

April Driver

April Driver is a wife and mother of two school-aged children. She loves using her writing skills and experience as a mom to provide helpful information to others. She enjoys lazy days with her family, reading, and exploring the beautiful Colorado outdoors.

Leave a Comment