Britax Graphene vs Millenia Car Seats: What’s the Difference?

When it comes to choosing the best car seat for your child, safety and comfort are paramount. With so many options available, it can be overwhelming for parents to decide which one to purchase. Two popular choices on the market are the Britax Graphene and Millenia car seats.

In this article, we will compare the different versions of these two models (Graphene, Graphene TEX, Graphene+, Millenia, Millenia TEX, and Millenia+) to help you make an informed decision for your child’s safety and comfort.

Key takeaway: Both car seat models offer safety and comfort features, but the Graphene models are more compact and lightweight, while the Millenia models have additional ease-of-use features and more recline options. They also differ slightly in their side impact protection.

Important note: This article is solely intended to provide a comparison of the features of these Britax car seats. It is not intended to be taken as advice or guidance on which car seat to choose. We recommend that you visit the Child Car Seats website to evaluate car seat safety and consult a professional installer for advice on installation. We also encourage you to consult the manufacturer for specific queries and suitability.


All six versions of the Britax Graphene and Millenia car seats are compliant with the AS/NZS 1754:2013 Standard, ensuring they meet the necessary safety requirements.

Age Suitability

All models are suitable for children aged 0-4 years, offering rearward-facing options for 0-12 months and extended rearward-facing options for up to 36 months. Forward-facing options are available for children aged 12 months to 4 years.

Compact Design

All Graphene and Millenia models feature a small footprint design, allowing them to nest between seatbelt buckles.

However, the Graphene car seats also feature an extra compact design that can accommodate three car seats across the back of a vehicle. Additionally, these models have the shortest depth for rearward-facing positions at 520mm, which is considerably smaller than the Millenia models’ rearward-facing depth of 600mm.

When comparing the weights of the car seats, the Graphene models are lighter at 7.8kg, while the Millenia models weigh 8.9kg. This difference in weight might be a consideration for families who need to move the car seat between vehicles frequently or travel often.

In summary, the Graphene models’ compact design makes them a better choice for families with limited space in their vehicle or those who require multiple car seats. The Millenia models’ larger dimensions may be more suitable for families who prioritize other features over compactness or have ample space in their vehicle.

RELATED: Britax Graphene vs B-First iFix

Convertibility and Installation Methods

Both Britax Graphene and Millenia car seats are convertible, meaning they can be installed as rearward-facing or forward-facing seats. All six models offer seatbelt and ISOFIX installation options, as well as top tether attachments.

ISOFIX is an internationally recognized standard for securing child car seats into vehicles using a rigid attachment system. It is an alternative to the traditional seatbelt method of installing a car seat.

However, none of the models features ClickTight Installation. All versions are also aircraft compatible, providing convenience for families who travel frequently.

Side Impact Protection

All six models feature Active Head Restraint (AHR) for side impact protection. However, only the Graphene models have EPS Foam Protection and Side Impact Cushion Technology (SICT) for the torso, while the Millenia models feature SICT for the head.


All models include a rebound bar (stabilizing bar) for added safety. The video below displays how this feature works:

Seatbelt lock-offs are available for forward-facing installation in the Graphene models and for both rearward and forward-facing installation in the Millenia models. All models feature a hassle-free harness, meaning there is no need for re-threading.

The Millenia models offer additional ease of use with push-button lower harness adjustment and a frontal easy-adjust headrest. The Millenia models also have four forward-facing recline positions, while the Graphene models have only two.

RELATED: Britax Graphene vs Graphene TEX


All models include Thermo 5 fabric for temperature regulation, buckle tongue holders, EZ buckle crotch pads, shoulder pads, and newborn inserts. The “+ Series” models (Graphene+ and Millenia+) also feature memory foam for added comfort.

None of the models have hardware ventilation or head pillows but they all have storage pockets, and Millenia models come with a vehicle seat protector.


When choosing between the Britax Graphene and Millenia car seats, consider your vehicle size, the number of car seats you need to fit, and your preferences for side impact protection. Both car seat models offer safety and comfort features, but the Graphene models are more compact and lightweight, while the Millenia models have additional ease-of-use features and more recline options. By understanding the differences between these models, you can make an informed decision on which car seat best meets your family’s needs.