Skip to main content
Cart 0
Your Bag


Radian® 3QX SafePlus™


3-stage newborn safety & 3-across: the advanced all-in-one convertible

or 4 interest-free payments of $100.00. Learn More
Total at checkout with annual subscription
Image displaying the text 'or'
Total at checkout with monthly subscription

Enjoy a lifetime of savings, care and protection with Lifetime Journey Care

Receive perks when you sign up for VIP Rewards

Sign Up

Create a free account and get 100 points.

Earn Points

Every time you shop and share your journey.

Redeem Points

Redeem points for exclusive discounts & perks.

Bonus Points

Exclusive anniversary & birthday bonus.

Radian® 3QX SafePlus™

3 stages of newborn safety and 3-across advanced all-in-one convertible car seat with 15 SafePlus™ features.

This seat has been awarded Best Bet Booster by IIHS.


  • 10 Years 1 Car Seat® - from Birth to Booster (4 - 120 lb) it's all you will need. Grows with your child, ultimate protection on every road trip. 4 modes in 1 seat!
  • SafePlus™ Rear-Facing Engineering up to 50 lb. Includes 3 stages of newborn protection and our steel anti-rebound bar that reduces rebound rotation by up to 50% while increasing space for your growing child.
  • Fits 3-Across - our famous slim-fit design with SafePlus™ 6-layer side impact protection with zero compromises to safety, space, or comfort.
  • Mechanically engineered from reinforced automotive grade high-strength steel, our unique core shell shields and protects your child.
  • One hand easy-adjust 12-position headrest, the SafePlus™ completes 6 layers of enhanced, rigorously tested, side impact protection.
  • The original and only all-in-one convertible car seat that folds for travel or compact storage. FAA approved for airline use.

Product Specs

  • Minimum User Weight: 4 lb
  • Maximum User Weight: 120 lb
  • Minimum User Weight - Rear Facing: 4 lb
  • Maximum User Weight - Rear Facing: 50 lb
  • Maximum User Weight - Rear Facing LATCH: 35 lb
  • Minimum User Weight - Forward Facing: 22 lb
  • Maximum User Weight - Forward Facing: 65 lb
  • Maximum User Weight - Forward Facing LATCH: 40 lb
  • Minimum User Weight - Booster: 40 lb
  • Maximum User Weight - Booster: 120 lb
  • Maximum User Height: 57.1 in
  • Product Height: 28.5 in
  • Product Width: 17 in
  • Product Depth: 16 in
  • Seat Weight: 31.3 lb
  • Number of Head Support Positions: 12

Care & Maintenance

Covers: Machine wash cold, line dry. Shell and Components: Spot clean

Warranty Information

12 months standard warranty - join lifetime journey care for up to 10 years extended warranty

Car Seat, Product Manual, Safe Stop®, Lap Belt Cushion, Rear-Facing Base, Cup Holder, Harness + Buckle Pads, 2-in-1 Infant Positioning Liner, Newborn Travel High Wedge

We recommend the following Diono® Accessories: Angle Adjuster®, Car Seat Travel Backpack, Side Impact Management Pod, Steel Anti-Rebound Bar, Anti-Rebound Bar Cover, Ultra Mat™, Easy View Mirror®

Yes, you should always read your Radian® 3QX® product manual and the vehicle's manual that you plan to install it in before use and is sewn into the seat cover. Find more information in our safety hub here.

Your manual is attached to the seat when you open the box. After you have read the manual it must be stored in the storage compartment on the back of the seat. Look for the manual storage icon to locate the manual.

Yes, your Radian® 3QX® SafePlus™ is entirely suitable for a newborn. Safest for children rear-facing from 5 lb to 50 lb. It's perfect for newborns with an infant positioning liner and high-riding wedge.

Yes, your Radian® 3QX® SafePlus™ is suitable for your toddler. We recommend rear-facing up to 50 lb/forward-facing from 50 lb to 65 lb in the 5-point harness system.

Yes you can use your Radian® 3QX® SafePlus™ for your big kid. We recommend forward-facing in the five point harness until 65 lb and then as a high back booster until 120 lb.

When installing your Radian® 3QX® SafePlus™ rear-facing in some vehicle, the space saving Angle Adjuster® can make more space available behind the front seat. Check out the video here.

Only use Diono® approved and crash-tested accessories with your Radian® 3QX® SafePlus™. The accessories you can use are here.

Diono® is the only car seat manufacturer to offer a folding convertible car seat. This makes it the perfect travel seat as it is so compact and folds into a handy car seat travel backpack. Saving space for trunk or home storage.

51 in is the minimum vehicle seat width needed between the vehicle's interior structures to fit your Radian® 3QX® SafePlus™. The Radian® fits 3-across in most mid sized Sedans up. Learn more here.

Your Radian® 3QX® SafePlus™ can be used rear-facing up to 50 lb or 44 in height. We encourage rear-facing as long as possible since it is the safest way for children to travel!

You can use your Radian® 3QX® SafePlus™ until 65 lb forward-facing with the 5-point harness and then until 120 lb as a high back booster.

Your Radian® 3QX® SafePlus™ uses 30-36 in between the vehicle's backseat and front seat back, depending on the vehicle's seat shape and contour. Fitting in most vehicles' rear-facing, use our space-saving Angle Adjuster® if more space is needed.

No. Always follow our guidelines regarding use of items not included with the car seat. We only recommend the use of accessories and spares parts from Diono® as all of these have been tested for use with your Radian® 3QX® SafePlus™.

Your Radian® 3QX® SafePlus™ does come with a cup holder. They are easy to install through the cup holder slot in the seat cover. Simply insert and twist to lock. Learn more here.

At Diono's Headquarters, a team of engineers continually work on improvements to our car seats. SafePlus™ engineering is the latest advancement in materials and rear and side impact protection, thoroughly tested and built into many of our car seats.

The Radian® 3QX® SafePlus™ must be used rear-facing. It works but reducing the rearward rotation in the event of an accident by up to 50% which protects your child.

The SafePlus™ side impact pod is a safety feature that can be installed on the car seat side closest to the car door. It works by redirecting side impact crash force energy away from the seat and the child.

Our car seat fabrics are tested to ensure they do not contain any legally restricted harmful flame retardants. In order to meet Federal and Canadian Motor Vehicle Safety Standards for flammability, our car seat fabrics do contain flame retardants.

Safety is paramount. Diono® ensures compliance with US Federal Motor Vehicle Safety Standards (FMVSS), US National Highway Traffic Safety Administration (NHTSA), and Canadian Motor Vehicle Safety Standards (CMVSS), regularly testing all car seats.

All Diono® convertible car seats have a life span of 10 years, starting from the date you purchase your seat. In the event the date of purchase cannot be determined then we use the date of manufacture.

Each Radian® is hand built by our manufacturing partners overseen by our highly trained quality control team.

Your Radian is heavy as our engineers will never compromise on the intergity of the famous Diono Steel core. Since launch our reinforced automotive grade high strength steel core is the heart of our Radian, protecting generations of kids everyday.

Your Radian® has a low seat base because as your child grows, they will want to get in and out of your car themselves. This low height makes it very easy for them to get into their seat before you harness them up.

The seat sides on the base expand as your child grows. Parents and Kids really love this feature on the Radian® 3QX® SafePlus™ as it makes travel so much easier