The best replacement for booster seat is car seat.

The best alternatives to booster seat are rated as following:
★★★★★  car seat
★★★★  high chair
★★★★  5 point harness
★  harness
★  convertible seat
★  convertible car seat
★  five point harness
★  child seat
★  convertible
★  high back booster
★  high back booster seat
★  no back booster seat
★  booster cushion
  backless booster seat
  bumbo
  child safety seat
  backless booster
  low back booster seat
  other infant seat
  car seat safety
  baby seat
  standard booster seat
  back
  car seats
  5 pt harness
  booster seat

Your alternative for booster seat is not listed? Suggest!
Speaking about booster seat, one probably shouldn't forget about latch.

Other search terms related to booster seat and their ratings are:
★★★★★ latch
★★★ harness
★★ latch system
★ shoulder strap
★ lap belt only
★ lap belt
★ tether strap
seat belt adjuster
You have in mind a companion for booster seat and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of booster seat in all years. Click on graph for more.
booster seat
car seat
high chair