ITEM# 50016

Diono Radian 3RXT All-in-One Convertible Car Seat 2019 Yellow Sulphur

This item is discontinued.
Your child’s security is Diono's top priority. The Radian 3RXT was engineered with premium, innovative features like a steel alloy frame, aluminum reinforced sidewalls, energy absorbing EPS foam and a reinforced adjustable head support to keep your little one protected and comfortable.

The Radian 3RXT keeps children comfortably rear-facing from 5-45 pounds for the safest possible position. Premium, plush head and body support cushions are included for newborns and infants.

Accommodates forward-facing children up to 65 pounds in a 5-point harness and converts to booster mode for kids 50-120 pounds. The aluminum reinforced, adjustable head support and sidewalls provide additional side impact protection.

Diono convertible car seats are made from steel for safety you can feel. The fully integrated steel frame is wrapped in thick engineered plastic to withstand severe crash forces. Deep, aluminum reinforced sidewalls provide excellent side impact protection, while energy absorbing EPS foam surrounds your child for ultimate safety. Diono car seats are definitely worth the weight.

  • Premium, plush interlock knit fabric (available in Black Cobalt, Black Mist, Black Plum, Black Scarlet and Essex colors)
  • Full steel frame for unmatched safety
  • Comfortably seats rear-facing children from 5-45 pounds
  • Seats forward-facing children from 20-65 pounds in a 5-point harness
  • Converts to a booster for children from 50 pounds up to 120 pounds, and up to 57" tall ? proper fit in booster mode
  • Unique SuperLATCH? system makes installation easy
  • Fits 3-across in most mid-size vehicles while providing spacious interior for child
  • Folds flat for travel and is FAA certified
  • Infant body support cushions and memory foam add comfort
  • Aluminum reinforced sides with energy absorbing EPS foam additional side impact protection
  • Safe Stop® energy absorbing harness
  • 12-position adjustable headrest
  • 5 shoulder and 3 buckle positions adjust for a comfortable ride.
  • Rear-facing tether capability
  • Expandable sides and long seat bottom offer proper leg support
  • Low-sitting profile makes it easy for your child to board
  • Angled cup holder keeps drinks upright and within easy reach
  • Cover is machine washable
  • Rubber bottom grips for no-slip installation
  • 10 year life from the date of purchase
  • Dimensions (in): 16 L x 17 W x 28.5 H
Product Reviews
out of 5.0
151 Reviews
Ratings Snapshot
of Reviewers
lyons, Illinois
Verified Buyer
January 10, 2024
Even for my newborn babies this car seat has been incredible. Always comfy and secure, beautiful and easy to clean.
  • Does not wash great.
Verified Buyer
Not for tall kids.
November 30, 2023
Great if kiddos aren’t tall, especially in the torso.
Customer Images
  • 3 across
  • Easy to wash cover
Best Uses
  • 3 across
  • Smaller kida
  • Install
  • Harness adjustment
  • Quickly outgrown by height, not a 10 year seat.
Nashville, TN
Verified Buyer
Great product
July 13, 2023
Diono knows their stuff. Chair is comfy and the kid easily gets in and out. Growing nicely with the kid.
Verified Buyer
Best Booster Seat
June 7, 2023
One of my favorite car seats -- definitely worth the price.
Spokane, Washington
Verified Buyer
Solid and safe
May 20, 2023
I lived this car seat for our little. It was easy to install and got great in our car for 3 across.
Abilene, Texas
Verified Buyer
Best car seat
June 18, 2022
I personally love how different these car seats are. They are slender so they fit really well in my car, also I love how comfortable my kids are in them.
  • Style, easy to install, comfortable, easy to clean.
San Diego, CA
Verified Buyer
Works only in certain installations
April 26, 2022
Bought this to use for grandparents car and travel. To make the rear-facing install work we had to buy an extra accessory and also put the seats all the way forward due to the very high seatback and be sure not to adjust them because a tether required installation. This didn't work out for a grandparent car seat, but we did use it for travel once old enough to forward face. For travel, this was heavy but useful in front facing installation and allowed 2 small adults to sit with it in the backseat.
Verified Buyer
Favorite convertible seat
December 30, 2021
I have been using Diono convertible seats since the days they were Sunshine Kids branding. They have come a long way and this is by far my favorite style. I love the fabric covers the back of the seat and protects my vehicle seats. Very easy to install. This colorway is gorgeous!
  • Fabric covers back of seat to protect vehicle seat
  • Easy install
  • Comfortable for kids
Verified Buyer
solid carseat
November 26, 2021
This carseat works well for needing 3 across in a smaller vehicle. The install is a little more difficult than others but overall a sturdy seat.
Houston, TX
Verified Buyer
Money well spent!
October 27, 2021
10 months later and this is by far my favorite car seat of the many we’ve owned. Other than the first and second time this was installed in our vehicles, it’s not that difficult to install. Especially now that my son is facing forward, it’s very quick and easy to set up. It is very heavy, but not bad if you are only moving it every now and then. It’s roomy, seems/looks very comfortable from the first time my son sat in it. In certain situations, I’ve had to have my 5yo son sit in it and it’s a quick adjustment to size it for him which is a big plus for me.
  • Spacious
  • Comfortable
  • Safety
  • Removable/optional cupholder/s
  • Heavy
Verified Buyer
Love diono
September 10, 2021
We love our Diono carseats! Both our kids have them now. Although they are a heavier carseat I love the comfort and design they provide. My favorite feature is the ratchet tightening.
Bloomfield hills mi
Verified Buyer
Best car seat
September 7, 2021
This is the best car seat ever! I love that baby can see the road and it has a cup holder and it has sides for safety.
Woodbine, Georgia
Verified Buyer
Best package and price
September 6, 2021
This is a great seat for smaller backseats. The three across capability is amazing.
  • solid
  • safe
  • great price point
  • heavy
Verified Buyer
Comfortable and compact, sturdy
August 20, 2021
We were recently rear-ended and needed to replace our car seats. After lots of safety research I chose this one for our tall and slim 5 year old as I wanted a metal frame and we will need to fit 3 across in a couple of months. She is very comfortable and happy in it! She asked if she could get another one to replace the full-sized car seat in her dad's car. Great safety ratings + comfortable kid is a win!
Bozeman, MT
Verified Buyer
Great for my 3 year old
June 20, 2021
We love the slim profile and sleek design of the Diono seats and much prefer this model with the headrests.
  • Head rest
  • Slim design
Best Uses
  • Front facing 5 point harness
Syracuse, NY
Verified Buyer
Best narrow carseat for 3 across in a sedan
May 11, 2021
We love our Diono! My son prefers it to his car seat with cupholders and all the extras. So slim and easy to install. Feels extremely safe. Will be purchasing more in the future.
Roseville , CA
Verified Buyer
April 24, 2021
Easy to install , my daughter fit perfect in it she loved it, it also fit perfectly in our car! This Is our 3rd diono they will forever be our favorite car seat !
Verified Buyer
Great all in one car seat
April 6, 2021
I love the color the Car seat feels very safe and my daughter actually sleeps in it ! I love this. Buy it !
  • Color safety size
  • No instructions in box that could find
Rochester, NY
Verified Buyer
My favorite car seat brand
April 3, 2021
I have purchased Diono car seats for all of my kids so far and haven’t been disappointed. Our car is pretty small, but we were able to put three of these in the backseat with no problem. Also the installation is pretty easy.
Verified Buyer
SPICA Cast Approved
April 2, 2021
Our 8 month old was being placed into a SPICA cast after her hip dysplasia procedure. I saw in a spica group that this car seat has worked well with fitting baby in the spica cast and they were 100% correct. The seat is heavy and definitely takes up a lot of space in our jeep Cherokee, but it works with baby’s spica cast and is keeping her safe. Car seat arrived quickly and in perfect condition.
  • Spica cast approved, fast shipping
Best Uses
  • Spica cast
  • Heavy seat
Kaitlin M.
Northern Virginia
Verified Buyer
Wait for a sale!
March 26, 2021
I got this package for a steal on Black Friday! It was an awesome value but would wait til a similar sale goes on. It’s easy to install. Feels extremely secure and the extras included are great. I love the seat protector pad and the two cup holders for her drink and her small stuffed animal to sit in :)
Verified Buyer
March 17, 2021
So happy we picked this up. The bonus pack has everything you’ll need to keep both baby and parents happy. As grandparents we wanted the same car seat my children have in their own vehicles and we couldn’t be happier in choosing this one. I really like where that the buckle is surrounded by fabric so no need you’ll pinch the baby’s skin while securing the straps. Well made, stylish and the price can’t be beat!
  • Peace of mind your baby is safely secured in a well
  • constructed seat.
Best Uses
  • Surrounded your baby in safety and stylish seating. Peace of mind. Can be used from newborn up- thats a plus.
  • In my vehicle (while rear facing) you can?t adjust the front seat to go back any further because it leans up agar the seat. A small price to pay for safety so I am in no way complaining. It?s a great safety seat for sure.
Verified Buyer
March 16, 2021
Love the quality of these seats! So easy to remove covers and clean. They are heavy so not super easy to move from car to car, but totally worth it for all of the safety offered for your child! We have identical triplets, so we have 3 in a row across our middle seat, and they fit perfect!
Verified Buyer
Awesome seat and ordering process
March 8, 2021
No surprise that this is a great car seat. My 4 year-old seems comfortable and happy and it provides enough room to have another car seat next to it in the middle seat (not another Diono, a Cosco Scenera Next for what it's worth...but may get another Diono now). Other than that, LOVE ALBEE BABY. Love that it's a NYC business (local for me) and have always received things quickly and in great shape and the prices are great. I try to order baby gear from here rather than Amazon or another big box store whenever I can.
Verified Buyer
Love it
March 3, 2021
Great deal on this set
Verified Buyer
Diono 2020 Radian
March 1, 2021
This kit has all you need. The slender seat fits easily without being bulky. It has a steel frame so feel confident moving to this seat with the hardness. Then we can move to the booster setting.
Verified Buyer
Great Carseat
February 26, 2021
My 3 year old has been using this car seat for a few months now and has been loving it(it’s his race car driver seat) unfortunately I’ve had to wash it several time due to potty training, and the Velcro has tore up the back of the cover pretty bad! Along with that the memory foam pad takes a really long time to dry, not the car seats fault just wish I’d known so I could have taken better care of it!
  • Good heavy car seat.
Best Uses
  • Great forward facing seat, this would never fit in my car as a rear facing seat!
  • Velcro tears up cover when washing!
North Carolina
Verified Buyer
Very happy
February 23, 2021
These are the only car seats I will buy for my older kids now. I am so happy with how sturdy they are and how it is now possible to fit three kids across the seat of the car. These car seats are incredibly sturdy and attractive as well. Very happy!
E E.
Tucson, AZ
Verified Buyer
Best car seat brand
February 20, 2021
We love this seat so much we bought one for our friends who are expecting and are preparing to buy another one (newer model) for our newest arrival! Cant beat a Diono!
E E.
Tucson, AZ
Verified Buyer
Fantastic seat
February 20, 2021
This is a wonderful carseat and we are so excited that it will grow with our child until they no longer need to be in a five point harness. Great service and quick delivery from Albee. Very pleased with our purchase.
Verified Buyer
Love this!
February 19, 2021
This bundle is absolutely amazing! I have a smaller SUV and it allows me to put three across. Love the colors as well
Verified Buyer
So happy
February 6, 2021
This is the seat we wanted and we got a great deal here and it shipped fast and arrived as described him with everything that it said it would we are very happy we will be shopping here again
Verified Buyer
Great car seat
February 5, 2021
Very comfy carseat for my 20m old. We kept it rear facing and she enjoys seeing the mirror placed in front of her.
  • Compact
Best Uses
  • Can use this upto the age kids stop using car seats.
  • Leg space reduces for the driver if you keep rear facing(it is applicable for all car seats)
Dallas, Texas
Verified Buyer
February 1, 2021
This is our second purchase of the 2020 Diono Radian 3RXT. We loved the all black one and decided to get a new one for our second vehicle and our new baby on the way. My 15 month old loves his car seat. Super comfy and not to bulky for the car. Will probably order 2 more with new baby on the way!
  • Slim car seat
  • Heavy to move around from car to car
Houston, Tx
Verified Buyer
Amazing Car Seat
January 27, 2021
Wish we would’ve purchased sooner! Sturdy, gorgeous color and my kids say they’re super comfy! My 6months old baby fell asleep in his, he hated his old one screamed the whole time we’d be in the car.
  • Comfortable
  • Sturdy
  • Great color
Santa Barbara, ca
Verified Buyer
Heavy, sturdy, not the tightest fitting seat
January 27, 2021
It’s heavy. It feels sturdy. But it’s not the tightest fit. Having two britax clicktight seats, I’m used to the burly heavy secure seat. This is not quite that. It’s ok. I feel fine using it. But the bottom can move if pushed. The hand tightening of the various straps and anchors is not the best approach. For this reason britax has been my gold standard of secure. But it’s a smaller car and I like having a seat that can travel with more ease. 3 of 5
  • Seat guards really only serve to add a layer of risk for looser fit.
Durham NC
Verified Buyer
Excellent seat, excellent price
January 22, 2021
This seat met all my expectations - we have an older version of this seat that we've been using for 10 years, and it hasn't changed much. The addition of a cupholder is nice (although I had to find a YouTube video to install it!) and the buckle is much easier to open (great for parents and kids that are responsible for their own buckles, less good for kids that like to unbuckle themselves during the ride). The newer LATCH attachments are also easier to use. This is still the best seat for 3 across, my two older children are riding comfortably on either side of it. And I have full confidence that my child is as safe as we can make him in this seat. It is extremely solid (and heavy) and well made. I like the head protection on the sides, it gives him a place to rest his head when he's tired. We didn't use most of the bonus accessories, but they are nice, and we'd likely have used them if we had an infant. Surprisingly, we didn't receive an installation manual with the seat, but it was easy to look it up online.
  • 3 across
  • Low-profile
  • Comfortable
  • Easy to buckle
  • Excellent sale price
Best Uses
  • 3 across
  • Older children
  • No installation manual in box (likely a mistake)
  • Strap cushions are huge and unwieldy - we chose to remove them. Other seats have more comfortable ones, and we might replace these with something more manageable.
Lauren S.
Belleville, MI
Verified Buyer
Love this car seat
January 20, 2021
We purchased two of these seats a couple of years ago for our twins and love them! They’re heavy duty and make us feel like our kids are very safe. We needed a new seat for our one year old, and Albee Baby had the best deal we could find. Shipping was fast too.
Verified Buyer
Great narrow seats!
January 14, 2021
I love these seats. I have a Yukon XL and the third row seat is definitely limited on space. With three kids in car seats (and 5 kids total!) I have to be very picky with the car seats I buy. Did a lot of research and measuring to decide on these. And they do not disappoint! They are heavy for sure, but I didn’t find them as difficult to install as other reviews said. I love the fact that even the back is covered nicely with the neoprene cover, the manual is neatly tucked into a pocket on the back- that took me a bit and a YouTube video to figure out! ;) I used the seat belt passed through the proper path in the seat and adjusted the angle so they reclined a bit and then used the head rest tether for added security. Was able to put three seats across- these diono seats, and then squeezed a booster for my big girl in the middle, thereby freeing up both captain seats in the second row! I’m thrilled.

The bonus pack stuff is nice too, though I havent used it yet. Came with a lot of diono brand baby car gear- cool mirror for rear facing kiddos, nice seat protectors, and organizer caddies, etc.
Customer Images
Verified Buyer
Not a true all in one
January 8, 2021
The seat itself is very well made, feels solid and comfy. However, I bought this for my 4yo to be used as a harness to booster. His shoulders are about 1" from hitting the head rest and it's not adjustable.
  • Narrow
Best Uses
  • When space is limited
  • Rear/forward harness only
  • Not an all in one
  • Doesn't work as a booster
Verified Buyer
Saved my children in a car crash
December 26, 2020
We just bought our second set after we were in an awful accident on Christmas Day. The car got totaled but the kids and the car seats were untouched! I’ll never own another car seat!!!
  • Life saver, so sturdy
Best Uses
  • Put in car and don?t take out!
  • Heavy but that?s what you want !!
Verified Buyer
New car seat
December 25, 2020
Baby grew out of her infant car seat and purchased this one. Could not be happier with my choice.
Seattle, WA
Verified Buyer
Sturdy and simple
December 21, 2020
Great seat. We struggled to find one that worked. We had graco slimfit but the buckle hurt my baby's thighs or seemed like it did because he would cry whenever we put him in the carseat. We got diono bc we heard it was good and our family member had it.

It was easy to set up and it came w a lot of accessories. More than we needed tbh. I wished that they noted where the instructions were but I had to Google to figure it out. Hint, it's on the side of the seat.
  • Safety, adjustable, sturdy, comfort
  • Price, heavy (hard to switch cars but doable if needed)
Sandy, UT
Verified Buyer
3rd D Radian Purchase
December 15, 2020
This is our third, love the stability and safety of these seats.
Fort Myers, FL
Verified Buyer
Great narrow car seat
December 11, 2020
We needed to buy a new car seat to fit 3 across in our jeep, this is wonderful, narrow and sturdy. It is heavy, but you can tell it’s made for safety. My 3 year old
Loves it
  • Narrow, easy installation
Verified Buyer
Good car seat, good deal
November 30, 2020
We bought this seat specifically because we wanted the “three across” for our vehicle when we eventually have a third child. So far we are happy with it. I don’t think it was too difficult to install. The fabric seems good quality and I like that it came with all the accessories. I don’t know if there is another seat on the market that is as narrow at the base as this one so I don’t know if this is the cheapest one out there but it was on sale so that I felt like I was getting a deal. I actually went back and bought a second of this same car seat for our other car. I’ll keep my eye out for more deals but I feel like this was a good buy.
  • Narrow base for having multiple seats in one row.
  • Good quality fabric.
  • Two cup holders and multiple other accessories.
  • Memory foam seat.
Best Uses
  • Three across in a row
  • Difficult to find instruction manual (was eventually found inside the fabric in a pouch, in Diono?s defense there was a little book symbol outside on the outside fabric to show this but I somehow missed it).
  • Some muscle is needed to cinch the seat down.
  • It comes with accessories you may not need (we already had a mirror so we didn?t need the one it came with).
  • Can be pricier than other seats.
  • Takes up a lot of room when rear facing.
Verified Buyer
Amazing Car seat!
November 27, 2020
I bought this so I could fit three car seats across in a small SUV (two toddlers and a baby). My son loves it and I was very happy to find something that was small enough but still very safe. I also like that it can grow with my child and be used a long time. Well worth the money!
Best Uses
  • to fit multiple car seats in the same row!
Verified Buyer
Solid Build!
November 25, 2020
This thing feels very stout! We have had it about eight months now and it has held up well to the wear and tear of toddler grime, goldfish snacks, markers with missing caps, etc.
  • Narrow width
  • Ability to use the Angle Adjuster (if needed)
  • Solid build
  • Extended Rear Facing ability
  • Adjusting the strap positions is not as easy as other car seats we have used in the past.
Verified Buyer
Forward facing
November 11, 2020
We needed three car seats across our Ford Edge. This fits nicely in the center facing the window. My daughter thinks she’s a grown up now that she can see out the windshield. And we feel safe knowing she’s secure in this car seat.
Verified Buyer
Rear facing
November 11, 2020
We needed three car seats. This one needed to be rear facing. And it’s a perfect fit for behind the driver seat, even with my 6 foot tall husband driving.
Customer Q&A