Sitzerhöhungen Ratgeber 2026: Wann der Wechsel sicher ist & beste Modelle

Why keeping the harness matters

The most important takeaway for 2026 is simple: max out the harness limits first. Most modern convertible and combination car seats (like the Chicco MyFit or Safety 1st Grand 2-in-1) accommodate children up to 65 pounds and 49 inches tall in 5-point harness mode.

A 5-point harness spreads crash forces across the strongest points of a child's body (shoulders and hips) and, critically, keeps them in the correct seating position even if they fall asleep or wiggle. A booster seat provides no restraint; it simply positions the adult seat belt. If a child leans forward to grab a toy or slumps while sleeping, the seat belt moves out of position, leaving them vulnerable.

Key Takeaway: If your child still fits within the height and weight limits of their forward-facing harness, keep them there. There is no safety benefit to switching to a booster early.

Are they actually ready? Use the 5-Step Test.

Age and weight are just numbers. The real test is maturity and belt fit. Before you purchase a Graco TurboBooster or a Diono Connect3, run your child through this checklist. If the answer is "No" to any of these, they are not ready.

1. Does the child weigh at least 40 pounds? (Ideally 50+ lbs for backless boosters).
2. Is the child at least 4 years old? (Most Child Passenger Safety Technicians recommend waiting until age 5 or 6).
3. Does the shoulder belt lay across the middle of the chest and shoulder? (Not cutting into the neck or slipping off the shoulder).
4. Is the lap belt low and tight across the upper thighs? (Not riding up on the soft belly).
5. Can the child sit properly for the WHOLE ride? (No slouching, no playing with the belt, no leaning over).

Item #5 is usually the dealbreaker. A 4-year-old might fit the seat physically but lack the impulse control to sit still for a 30-minute drive to school.

Understanding the safety differences

Many parents assume backless boosters are just the "next step" after high-back boosters, but the decision actually depends on your vehicle's geometry and your child's sleep habits.

When to choose a High-Back (e.g., Chicco MyFit in booster mode)

• Your vehicle seats have low seatbacks or no headrests.
• Your child frequently falls asleep in the car.
• Your child is new to boosters and needs the tactile reminder of the side wings to stay in position.

When to choose a Backless (e.g., Graco TurboBooster LX, Diono Connect3)

• Your child is taller and their ears are above the top of the high-back shell.
• Your vehicle has high seatbacks/headrests to support the head against whiplash.
• You need a portable option for carpools or travel (like the BubbleBum Inflatable Booster).

Pro Tip: Many high-back models convert into backless boosters, giving you the best of both worlds as your child grows.

Best Overall: Graco TurboBooster LX

For years, the Graco TurboBooster has been the gold standard for fit and affordability, and the 2026 iterations continue this legacy. The LX model features a rigid LATCH connection (Affix system) which keeps the empty booster secured to the vehicle seat so it doesn't become a projectile when the child isn't in it. It consistently rates as a "Best Bet" by the IIHS for belt fit.

Best for 3-Across: Diono Connect3 R

If you are trying to fit three kids across the back of a sedan or mid-sized SUV, every inch counts. The Diono Connect3 is designed specifically for this puzzle. It has a narrow footprint but remains comfortable for wider kids. It's lightweight and easy to transfer between cars.

Best for Travel: BubbleBum Inflatable Booster

For Uber rides, taxis, or flying (to use in the rental car at your destination), the BubbleBum remains unbeaten. It deflates to roll up into a backpack and meets all safety standards. Note: It requires a bit more active setup to ensure the belt guides are used correctly every time, so it's better for occasional use than daily driving.

Best Transition Seat: Chicco MyFit

If your child is outgrowing their convertible seat but isn't quite ready for a dedicated booster, the Chicco MyFit is a harness-to-booster combination. It allows you to keep them harnessed up to 65 lbs, and then converts to a sturdy high-back booster. It’s bulky, but the safety features and comfort are top-tier.

It's not just 'plop and go'

Even though boosters seem simpler than harnessed seats, installation errors still occur. The most critical factor is the lap belt position.

The Danger Zone: If the lap belt sits on the child's stomach, crash forces can cause severe internal organ damage (known as "seat belt syndrome") in an accident. The belt must touch the top of the thighs/hips.

The Shoulder Fit: The belt should cross the collarbone. If it rubs the neck, kids will instinctively tuck it under their arm or behind their back. Never allow this. If the belt is under the arm, it breaks ribs in a crash. If it's behind the back, the head and torso fly forward unchecked. If the belt doesn't fit right, the booster is the wrong model for your child or vehicle.

What the law says vs. what physics says

State laws vary wildly. Some say you can ditch the booster at age 8, others rely on height. However, the laws of physics don't change when you cross state lines.

The 5-Step Test (mentioned earlier) is the only reliable metric. Most children do not pass the 5-step test until they are 10 to 12 years old and roughly 4 feet 9 inches tall.

2026 Standard: Don't be pressured by "middle school stigma." Keep your child in a booster (even a discreet backless one like the Diono Connect3) until their feet are flat on the floor with their back all the way against the vehicle seat and their knees bent comfortably over the edge.