What is an all-in-one car seat?
How to choose an All-in-One Car Seat
The All-in-One car seat, also known as a 4-in-1 car seat, is designed for extended use as your child grows. These car seats can easily transition from rear-facing to forward-facing to booster mode. Chicco all-in-one car seats for newborns, toddlers, preschoolers, and big kids provide adjustable features that accommodate each of the four stages of car seat use children grow through. With an all-in-one car seat you can have a single seat that does it all!
Checklist for Choosing the Best All-in-One Car Seat
Purchase a single all-in-one car seat that safely secures your child from infant through big kid Keep your little one in the safer, rear-facing position for longer – up to 40 lbs. Easily transition from rear-facing, to forward-facing and booster mode 
An all-in-one is not portable or stroller friendly like a traditional infant car seat Some wear is to be expected over the life of the seat, though seat fabrics are machine washable You miss out on the milestone of graduating to a new car seat All-in-One Car Seats - Frequently Asked Questions
The best all-in-one car seat will fit your child properly at each and every stage of use in addition to fitting your vehicle. Further, an all-in-one car seat is designed to last for several years so make sure you understand how the seat works in all of the stages and if needed, replacement parts are available.
Using the LATCH system or the vehicle seat belt are both good options as long as you get a secure, tight installation. Consult your product manual to ensure that installation with LATCH is an option based on the child weight limit for LATCH use. LATCH use is weight-limited based on the overall weight of the child occupant plus the weight of the car seat. You must also check your vehicle manual to confirm appropriate LATCH seating positions.
Many all-in-one car seats have machine washable fabrics. Always refer to the product manual for specific details on how to remove the seat cover and properly clean the seat. Some brands include step-by-step instructional videos for removing and replacing the seat pad for cleaning so be sure to check your car seat manufacturer’s website.
An infant car seat can only be used rear-facing and is used for a limited amount of time, usually for the first 1 to 2 years. It offers the convenience of a 2-part design which consists of the car seat carrier and stay-in-car base. The car seat carrier clicks securely into the base and compatible strollers, making transporting your little one conveniently easy. If your child will be riding in more than one vehicle, you just need to purchase additional infant car seat bases.
An all-in-one car seat offers a longer duration of use, accommodating the growth of your child and provides all major modes of car seat usage: Rear-Facing with Harness, Forward-Facing with Harness & Booster Mode. An all-in-one car seat stays in the car, it does not click into a separate base or stroller. Because of its bigger size and weight, it is not portable like an infant car seat. If your child will be riding in more than one vehicle, you’ll likely want to purchase an all-in-one car seat for each vehicle.