Booster seats are designed to keep your child safe when they are too large for a convertible car seat but too small for your car's seat belt alone. For younger children, we offer companion reports on infant car seats (which double as infant carriers) and convertible car seats (which can accommodate infants in the rear-facing position and older kids in the forward-facing position).
Booster seats for younger children, high-back seats that are also called combination or hybrid seats, convert from a forward-facing seat with a five-point harness to a belt-positioning booster seat suitable for older children. High-back, belt-positioning booster seats are thought to be the safest option for older kids because they offer additional side-impact protection, but they're big and bulky. Backless belt-positioning booster seats are a smaller, more portable option, but experts say they don't offer as much protection in a crash.
High-back booster seats are a safe bet, experts say. High-back boosters raise children so that a vehicle's seatbelts fit properly. Unlike combination seats, they do not offer a five-point harness, but they do offer additional head, side and back support that backless boosters lack, experts say. According to editors at ConsumerReports.org, backless boosters aren't as likely as high-back boosters to position a vehicle's seatbelt in line with a child's shoulders and keep it there. Indeed, high backs performed better than backless boosters in recent crash tests. While some backless boosters come with a belt-positioning clip, the tests showed that the belts slip when kids squirm.
In 2005, researchers at Children's Hospital of Philadelphia found that kids ages 4 to 8 in backless booster seats were as likely to suffer injuries (mainly head injuries) as kids the same age in seatbelts alone in side crashes, but high-back booster seats cut kids' injury risk by 70 percent. That's important, considering that side crashes cause 42 percent of car-crash deaths for children ages 8 and younger in the backseat, according to the National Highway Traffic Safety Administration (NHTSA).
While many high-back boosters convert to backless models, experts at ConsumerReports.org caution that seat belts fit kids better on backless-only models versus high backs that have been converted to backless boosters.
Combination booster seats may offer the best of both worlds. Traditional booster seats simply boost your child so that the car's seat belt fits properly -- over a child's thigh and shoulder bones, instead of his more vulnerable belly and neck. However, experts say it's safer to keep children strapped into a five-point harness (two shoulder straps, two hip straps and a crotch strap, which clip together) as long as possible -- past the old recommendation of 4 years and 40 pounds. Combination booster seats can keep your child in a five-point harness up to 50 or 65 pounds or more, depending on the model. These seats can be used as a regular belt-positioning booster seat after your child outgrows the harness and until the vehicle seatbelt fits properly -- usually when your child reaches both 80 pounds and 4 feet 9 inches. The downside? Combination seats can be heavy and bulky, and they're generally among the priciest boosters on the market.
A backless booster is a space-saving option for big kids. Despite high-back boosters' seeming safety edge, parents may still consider a backless booster seat for several reasons. The NHTSA still says backless booster seats are fine to use, unless your back seat has a low back or lacks headrests (in which case you need a high-back booster seat). Backless boosters are also smaller, lighter and more portable than high-back seats -- qualities that make them ideal for families who travel, kids who carpool or vehicles where space is tight, including cars that may need to fit three child safety seats in one row. Expert tests also show that backless boosters are often easier to use than high-back models.
ConsumerSearch has analyzed more than a dozen expert reviews and hundreds of owner reviews to evaluate booster seats' safety, ease of use, lifestyle features and customer service. The result is our picks for the best booster seats on the market.