Hi there! We're here to help you decide between the Diono Radian 3RXT Safe+ and the UPPAbaby Knox.
Our goal is to provide you with the information you need to feel confident that you're choosing the optimal car seat for your family's needs and budget. Let us know if you have any other questions!
At A Glance
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
Type |
Convertible Rear-Facing Forward-Facing High Back Booster Backless Booster |
Convertible Rear-Facing Forward-Facing |
Current price |
Currently unavailable
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Currently unavailable
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Rating | 4.58 | 4.40 |
Our Thoughts
The Diono Radian 3RXT Safe Plus and the UPPAbaby Knox are both strong contenders in the convertible car seat market, each offering a unique balance of safety features, functionality, and style.
Starting with safety, the Diono Radian excels with its standout features such as the steel-reinforced frame and EPS foam protection. These features are particularly valuable during side-impacts, offering an additional layer of security. Moreover, it accommodates a wider range of weights, supporting up to 50 pounds in rear-facing mode and 120 pounds in booster mode. This means that your child can stay in the rear-facing configuration longer and transition to booster mode when they are older, compared to the Knox seat, which supports up to 45 pounds in rear-facing mode and doesn't have a booster mode.
When it comes to usability, the Diono's slim design provides a definite edge for families with multiple children or smaller vehicles, as it can comfortably fit three across in most cars. But keep in mind, some parents noted challenges with the Diono car seat's installation and reassembling, especially of the seat cover, which could be a significant factor if the seats need to be removed frequently or cleaned often.
On the other hand, the UPPAbaby Knox draws attention with its premium aesthetics and innovative safety elements, such as the integrated Koroyd technology to absorb crash impact forces. However, the one major setback is its bulkiness. This could become a problem in smaller vehicles, or if there is a need to accommodate multiple car seats. Additionally, installation is often considered challenging, which could be problematic for parents who need to switch the seat between vehicles frequently.
If you're seeking a car seat that offers a balance of top-tier safety features, space efficiency, and long-term usability, the Diono Radian 3RXT Safe Plus is the recommended choice. However, if luxury and style top your list and you have a larger vehicle, the UPPAbaby Knox may be a worthy consideration. What's crucial is to consider your child's size, your vehicle space, and the amount of time and effort you're willing to spend on installing and maintaining the car seat.
Key Details
Radian 3RXT Safe+ | Knox | |
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Brand | Diono | UPPAbaby |
Type |
Convertible Rear-Facing Forward-Facing High Back Booster Backless Booster |
Convertible Rear-Facing Forward-Facing |
Weighted Rating | 4.58 | 4.40 |
1 yr Price Range | $259.99 - $349.99 | $299.99 - $349.99 |
Current price |
Currently unavailable
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Currently unavailable
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Value |
![]() Offers robust safety features and long-term usability, justifying its price. |
![]() The Knox is priced at the higher end of the market without corresponding enhancements in convenience or functionality. |
Safety |
![]() Steel-reinforced frame and comprehensive protection measures are a standout. |
![]() Features like integrated Koroyd technology and Side Impact Pods offer advanced safety beyond standard requirements. |
Features |
![]() The 12-position headrest and machine-washable cover add notable convenience. |
![]() While the chest clip's one-button release and the machine-washable fabric are nice, they don't set the Knox apart in a crowded market. |
Installation |
![]() Installation and reassembly, especially of the seat cover, are noted as challenging. |
![]() Installation challenges are frequently noted, which could be a significant deterrent for parents who need to move the seat between vehicles. |
Cleaning |
![]() The machine-washable cover is practical, but reinstallation can be cumbersome. |
![]() The machine-washable fabric is a convenient feature, allowing for easier maintenance and cleanliness. |
Size |
![]() Its narrow design is ideal for fitting multiple car seats in a vehicle. |
![]() Its premium build comes with added bulk, making it less suitable for smaller vehicles or those needing to fit multiple seats. |
Review | Click here | Click here |
Comparison of Specifications
While features and reviews provide a sense of real-world use, the specs offer quantifiable details on sizing, limitations, and more. Comparing key measurements and ranges side-by-side is crucial for ensuring you choose a seat properly fitted for your child and vehicle.
We've compiled the weight limits, height limits, dimensions, and other vital statistics for the Diono Radian 3RXT Safe+ and the UPPAbaby Knox. This data will confirm whether each seat can accommodate your child's current size and projected growth. Specs like seat depth and width are also important for assessing fit with your car's backseat.
Review the following key measurements for both seats. Pay special attention to the height and weight limits to ensure your child falls within the safe ranges.
Height and Weight Limits
Rear-facing
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Height Range | 18 - 44 inches | 0 - 49 inches |
Weight Range | 4 - 50 pounds | 14 - 45 pounds |
Forward-facing
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Height Range | 30 - 57 inches | 0 - 49 inches |
Weight Range | 22 - 65 pounds | 25 - 65 pounds |
Booster
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Height Range | 40 - 57 inches | |
Weight Range | 40 - 120 pounds |
Dimensions and Weight
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Width | 17.0 inches | 18.8 inches |
Height | 28.5 inches | 32.5 inches |
Depth | 16.0 inches | 23.8 inches |
Weight | 30.6 pounds | 32.5 pounds |
Core Specifications
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Model Year | 2018 | 2022 |
Made In | China | China |
Frame Material | Reinforced Steel | Koroyd Technology |
Safety and Compliance
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Federal Safety Standards | Meets all standards | Meets all standards | ||||||||||||||||||||||||||||||||||||||||||||||||||
Configurations FAA-Approved for Airplanes |
Forward-Facing Rear-Facing High Back Booster Backless Booster |
Forward-Facing Rear-Facing |
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NHTSA Ease-of-Use Ratings |
Rear-Facing Mode
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Rear-Facing Mode
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Previous Recalls | This car seat has never been recalled. | This car seat has never been recalled. |
Features
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Attachment Methods |
LATCH Seatbelt |
LATCH Seatbelt |
Harness Type | 5-Point | 5-Point |
Cup Holders | Has cup holders. | Has cup holders. |
Warranty and Durability
Diono Radian 3RXT Safe+ | UPPAbaby Knox | |
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Manufacturers Warranty Length | 1 year | 2 years |
Lifespan | 10 Years | 10 Years |
Additional Links
See all Diono car seats | See all UPPAbaby car seats |
Full review of the Diono Radian 3RXT Safe+ Full review of the UPPAbaby Knox |