Anyone entering a childcare store for the first time is hit with an alphabet soup. The rule behind the names is simple: the "i" prefix means the seat is approved under the R129 standard, which measures the child in centimeters rather than kilograms. The rest of the name describes what the seat does. Spin rotates, Harbour clicks into a base, Traver is for the older ones.

Three things decide your choice: the child's height today, what your car has under the upholstery, and how long you want the seat to last. The model name comes later.

The entire range on a ruler

This is the part that no catalog shows you. Each bar is the height the model covers, to scale. This is how you can tell at a glance where one seat ends and another must begin.

Stage 1: the infant carrier, from 40 to 75 cm

All Joie infant carriers start at 40 cm and are suitable from birth. The difference between them lies in your routine, and not in safety.

Are you buying a base? Think four years ahead

Almost all Joie infant carriers can be installed using the car's three-point seat belt and are equally safe. The base is for speed: you click in and out in one gesture, instead of threading the belt every time.

Where the decision truly matters is what comes next. The i-Base Encore rotates 90 degrees to the door with the carrier on top, and continues to be used later for the i-Harbour, up to 105 cm. You buy once for two stages. A fixed base only lasts a year.

See Joie bases and compatibility

Stage 2: from 40 to 105 cm

From here on, the child stays in the same seat for about three years. Rotating seats exist for a practical reason: they rotate the seat to the door, so you don't have to bend into the car to tighten the harness blindly, in the rain, every single day.

Why doesn't the i-Spin Safe rotate 360 degrees?

Because if it turned forward, it would no longer be what it is. It rotates 90 degrees towards the door, just enough to seat the child, and nothing more. It was designed exclusively for rear-facing travel up to 105 cm, and is approved by the Swedish Plus Test, the most demanding test that exists for rear-facing seats.

If your priority is containing neck forces, this is the choice. If your priority is day-to-day ease, choose one of those that rotate fully. Both are legitimate priorities.

Stretching rear-facing up to 125 cm

Almost all ISOFIX seats on the market reach their limit at 18 kg, around age 4. It is a physical barrier: ISOFIX was designed to withstand up to that point.

• High-strength aluminum frame.
• ISOFIX with support leg, Plus Test approved up to 23 kg.
• Adjustable legroom, for rear-facing travel up to nearly age 7.

See the i-Prodigi Signature, €539.95

Stage 3: from 4 to 12 years

From 100 cm on, the child leaves the internal harness and is secured by the car's seat belt. A booster seat with a backrest is non-negotiable, and the reason is geometric: without it, the belt passes over the neck and abdomen, which is exactly where we do not want the force to be in an impact.

Frequently Asked Questions

What does the "i" in Joie names mean?

It indicates approval under the R129 standard, also known as i-Size. It is the standard that classifies seats by the child's height in centimeters, instead of weight, and requires mandatory rear-facing travel until at least 15 months.

Do I really need to buy a base for the infant carrier?

No. Almost all Joie infant carriers are installed using the car's three-point seat belt and are equally safe. A base is purchased for the speed of clicking it in, and it makes more sense if it is a modular base that continues to be useful in the next stage.

How long should I keep the child rear-facing?

As long as the seat allows. A young child's head represents a much larger portion of their body weight than in an adult, and it is rear-facing travel that distributes the force of an impact along the back instead of concentrating it on the neck.

Isn't a seat that goes from 40 to 145 cm a better deal?

It works out cheaper over time, but a seat that covers all stages has to make compromises at each one. If the budget dictates, it pays off. If you can divide it into two stages, each seat serves the stage the child is in much better.

Can I use a second-hand seat?

Only if you know its full history. A seat that has been in an impact, even a minor one, no longer offers the protection it was tested for, and internal damage cannot be seen from the outside. There is also an expiration date on the plastics.

How do I know if this seat fits in my car?

You can't tell just from the catalog. The angle of the seat, the space to the front seat, and the position of the anchors change from car to car. Measure the child, use our "Cadeirómetro" to figure out which stage is theirs, and then test it in your own car.

And at home, which stage is your child in? Tell us in the comments.

Sources: UNECE Regulation No. 129 (i-Size); Article 55 of the Highway Code; Joie technical documentation by model; ADAC and Swedish Plus Test results. Prices and availability subject to change and valid as of the date of this publication. Last check: September 12, 2026.