Be sure to read our complete review of infant car seats to learn more about the models that won awards and why.
Why Buy an Infant Car Seat?
You will need to purchase an infant car seat if you ever plan to put your baby in any kind of motorized vehicle. It might honestly be one of the only must have items on your baby gear list (okay diapers too, but you get the point).
The video below, by the Children's Hospital of Philadelphia, provides an excellent overview of the role infant car seats play in protecting your infant, as well as safety tips on proper installation.
Size and Weight Limits
Most of the car seats we reviewed are marketed as suitable for babies up to at least 30 lbs weight and height of 32 inches. Plus, the marketing of higher-end seats frequently tout a larger weight capacity closer to 35 lbs or 40 lbs leaving many new parents wondering if they need this extra capacity.
So, is a car seat capacity up to 30 lbs and 32 inches enough? Or, should you buy a seat with a higher weight capacity such as 35 or 40 lbs?
The answer is that 30 lbs and 32 inches are plenty. It is really only the height limit that matters. The higher weight capacity figures are pretty much just marketing hype you can ignore.
We recommend you switch your baby to a rear-facing convertible car seat at around 9-11 months age. During that age window, it is the height limit of car seats that your baby is likely to exceed. Twelve-month-old baby boys at the 95% percentile are only 28 lbs, well within the upper limits of many car seats. Many car seat manufacturers use higher weight limits in the sales and marketing materials, implying that a capacity of 35 or 40 lbs is better than 30 lbs. For the vast majority of babies, any weight capacity over 30 lbs is just marketing you can ignore.
CDC baby boy age vs weight growth charts (pdf), even a 95th percentile baby boy will weigh under 28 lbs and be just shy of 32 inches length on their 12 month birthday (95th percentile means they are growing faster than 94 kids out of every 100). So, you can see from CDC data that your baby is likely to exceed the height limit long before they exceed the weight limit.
So, let's focus on length limits.
Most of the car seats we reviewed (10 of 15) offer a maximum length of 32 inches. The average baby boy will reach 32 inches and 26 lbs at 18 months age, and the average baby girl will reach 32 inches and 25 lbs around 19 months. But, keep in mind that your baby will switch to a convertible car seat when age 9-12 months, so don't need to pay extra or worry about weight capacity over 30 lbs.
Four of the 15 seats only offer a maximum of 30-inch length, including one of our Editors' Choice winners, the Chicco Keyfit 30. Is 30 inches length enough?
Yes, but if your baby grows taller faster than most, a 30-inch length limit might mean moving up to a convertible seat a bit sooner. That isn't a problem, but it's something to be aware of. The CDC stats show that the average boy baby will reach 30 inches long in about 12 months, and girls will get there about 14 months old. A fast growing, 95th percentile boy will reach 30 inches in about nine months.
Most parents switch from an infant seat to a convertible car seat sometime in the 9 to 12 month age range. So, with seats rated for at a length of at least 30 inches, the infant seat will serve its purpose in the age range that most matters, and you can simply move up to a convertible seat when it's the right time for your baby without stressing about it.
We'd advise that you essentially ignore size and weight capacity as a key consideration in your car seat purchase decision. The limits just don't matter.
Types of Car Seats
There are two basic kinds of car seats, the infant style car seat (above left) and a convertible car seat (above right). Both varieties can be used with infants and have some similar features and functions, but they are not the same. There are pros and cons to each style of seat thanks to their designs and overall limitations.
Infant Car Seats
Infant car seats look and behave somewhat differently than convertible car seats. Because they are designed with smaller babies in mind, they have features that support little bodies and make your life with an infant more convenient.
- Separate Bases/Detachable Seats — With an infant seat the base and the seat are detachable, and this simple feature is very convenient with an infant. The way it works is you install the base in your car, more or less permanently. The seat is then clicked on to the base. Two parts is a nice feature that allows parents to leave the base in the car correctly installed while having the freedom to remove the carrier to keep baby restrained or asleep. The carrier can be moved via the handle, or placed in a compatible stroller. Most strollers offer a range of car seat adapters. We find the ability to click the car seat into a frame stroller or a full-size stroller to be very convenient for running quick errands without having to wake baby for a seat/carrier transfer.
- Rear Facing Only — Infant seats always face the rear of the vehicle (required by law), which is a safer position to be in in the event of a head-on collision (the most common type of crash).
- Canopy —
- Smaller Weight and Height Restrictions — While some of the infant seats now have a larger weight range than they used to (4-40 pounds), their range is still less than convertible car seats because the seat is specifically designed for smaller bodies as opposed to trying to fit all body sizes. This design might seem like a limiting factor or a reason not to purchase one, but it is part of what makes this kind of seat special and better for newborns and smaller babies to travel in.
Convertible Car Seats
move from an infant seat to a convertible car seat once your baby is 9 to 11 months old. However, the manufacturers of convertible seats offer compatibility with infants as small as 5 pounds and up to 40-70 pounds depending on the model. The word "convertible" comes from the ability to use the seat in a rear-facing position initially, and then later flip the seat around to "convert" it to a forward facing seat. The ability to use a convertible seat with an infant may tempt you to consider buying just a convertible car seat and skip buying an infant seat entirely. We urge you not to do that. In our opinion, an infant seat is better designed for the size of a young baby and a lot more convenient to use. The ability to keep the separate base of an infant seat installed in the car, and simply click-in or out the car seat carrier is very convenient. In comparison, using a convertible car seat with an infant is a hassle, in that you must always put them in or take them out of the harness system every time you transition to or from the car.
We at BabyGearLab feel that an infant seat is the best choice for newborns because they are much more convenient to use, and are specifically designed for smaller bodies, and thus offer a better fit. Switch to a convertible car seat once your baby outgrows their infant seat, usually around 9 to 12 months of age.
Overview of the Basics
Even though all seats have passed crash tests, they are not all created equal. In the following sections, we will cover the common features you should consider when looking at different infant car seats.
Never Never Never leave baby unattended in an infant car seat. Injury and death have occurred from accidents related to car seat carriers being left unattended while the baby slept. Also, never leave the carrier on a soft surface like a bed or couch to avoid a rollover suffocation hazard, or on a high surface like a countertop to avoid a fall.
As you would expect, crash tests play a key role in the basic performance of car seats, and also in differentiating products. To that end, each car seat must pass a Federal crash test safety standard administered by the National Highway Transportation Safety Administration (NHTSA). To pass the standard each seat must be subjected to crash testing in a facility designed to simulate collisions using a sled and crash test baby dummies. These sled based tests utilize data from sensors implanted in the test dummies that measure the amount of force exerted on dummy baby's head and chest based on a 30 mile an hour collision simulation.
The good news for parents is that these Federal safety requirements ensure that every seat sold in the US provides at least a basic level of crash protection, and thus can be considered safe.
Even though every seat on the market has passed the minimum Federal safety requirement tests, some have passed with better results than others. In our review of competing car seats, you will see that we combined our own crash test data with data obtained from NHTSA's crash tests, and analyzed these tests in a side-by-side comparison format to demonstrate how each seat compares to the Federal maximum for G forces and how each seat compares to the others.
Given that some seats perform better in crash tests than others, we gave higher scores to those seats that provide an extra margin of protection in crash test results. We think that matters and deserves to be one of the factors you take into consideration in your purchase decision.
Improperly installed car seats can cause infant injury or death in auto accidents. It is not enough to have and use a car seat, you must use it properly and consistently.
Side Impact Protection Claims: Let the Buyer Beware
Some of the seats we tested claim side impact protection (SIP) is part of the seat's design. We suggest consumers remain skeptical about these SIP claims as there is no set standard on what it means for a seat to have SIP, and the term means different things to different manufacturers. While a plan for possible side impact testing of car seats is in the works, there is currently no common standard or test available to determine the safety of side impact features. Also, the term is one filled with ambiguity. For example, Safety 1st claims SIP in the case of a side collision and cites independent tests they have paid for to determine the efficacy of their design. Alternatively, Graco claims SIP and independent testing, but their definition of SIP means the harness will keep your child in the seat in the event of a side collision. We think most parents would consider keeping the child restrained in the event of a side-impact to be a basic feature offered by all products, rather than a specific side-impact protection feature.
Certainly, extra safety features are a bonus, but we want parents to be aware of the somewhat "Safety washing" that is happening in the marketing of side-impact protection in the industry. Because there is no industry standard, and each manufacturer means something different when they say pretty much the same thing, it means the terms used to describe "side impact" have no meaning in and of themselves. This lack of agreed upon definition requires us, or parents, to do further research to determine how each company is choosing to define the term, and how each is claiming to have tested their design, if they are claiming it has undergone tests at all.
We feel that manufacturers are using side-impact protection as a marketing claim, and we'd much prefer that there was an actual standard for these claims to create a focus for each manufacturer's design engineers. For now, in our efforts to determine how the seats were tested or what most manufacturers meant when stating the seat offers SIP, we came up disturbingly short in locating compelling information or evidence to support the claims.
Side Impact Crumple Zone
The Cybex Aton 2 has a hard plastic side-impact "lever" that can be opened and used on any side where a person is not sitting next to the car seat. The Cybex Cloud Q has a similar device that pulls out from the shell side. This simple addition has helped them earn an ingenuity award, and it potentially helps absorb external forces generated by a side collision before they reach the seat, thereby creating something of a crumple zone in the event of an accident. We have no way of knowing how well this feature works or if it will work predictably in a real crash as opposed to a simulated sled crash test. They also have a load leg on the Cybex Cloud Q that crash test results indicate does improve safety for baby.
Every seat is essentially made up of the same kinds of materials and basic design. There aren't large differences between the seats we tested in this regard. They all have a hard plastic shell with a dense foam padding as the second layer. Next, they either have softer comfort style padding and/or a fabric cover, and some of the seats also offer additional inserts to help position baby more comfortably or safely. These inserts can be on top of the fabric or under the padding and cover. Some seats also offer additional or larger pads around the head area presumably for impact protection; some explicitly state this is the purpose of the additional head wings, while others do not. This makes it difficult to tell if the feature is intended to improve safety or merely give the illusion of improved safety.
Our view is that the differences in seat construction that really matter are the ones that show up in crash test performance, as well as those that affect the baby's day-to-day comfort.
The external hard plastic shell of all the car seats we tested is the first line of defense in an accident. The shell provides structural support and contains the inner layer of energy absorbing hard foam inside. In this way, an infant seat works much like a bike helmet, which also uses an exterior shell of hard plastic combined with a layer of energy absorbing hard foam between the shell and your head.
- Hard Foam — All the seats we looked at have stiff foam as their primary energy absorbing material that helps protect the baby in the event of a crash. This foam is similar to that found in many bike helmets and is the industry standard for impact protection. The primary difference between seats is how much and where the location of foam is inside the shell. Most just have the hard foam on either side of the head or encompassing the side and back of the head. A few had foam inside the entire shell encompassing all parts of the baby. We particularly liked that the Peg Perego Primo Viaggio 4-35 has a hard foam headpiece in addition to hard foam in one piece throughout the seat, as well as under the bottom and leg areas.
- Soft Foam — Some seats offered a softer foam around the head portion of the seat also
On top of the foam and standard seat padding there might be extra padding, that can be anything from an infant insert piece that helps position small infants properly, to padding on the harness to help keep baby's head positioned and/or avoid rubbing on the straps. The Cybex Aton 2 offers a stiff foam infant insert that goes underneath the car seat padding and is unique in the group. The trick will be remembering to remove it when baby outgrows it.
The Three Ways to Anchor the Car Seat
There are three different methods used to strap a car seat down in a vehicle. We'll give you an overview of each and the most common reasons to use one over the others.
- Installing the Base with LATCH connectors — Since 2002, most cars in the US have been required to include LATCH connectors on the left and right side rear seat positions (but not the center seat). LATCH stands for Lower Anchors and Tethers for CHildren (LATCH). This type of connector was invented to provide a simple and reliable method of attaching car seats to vehicles. We recommend using LATCH connectors when they are available since they are usually the best and simplest way to assure a tight and secure connection. Most parents place their child in one of the side seats where LATCH anchors are located, typically the right rear passenger side to make it easier for the driver to see the baby.
- Installing the Base with a Seat Belt —
- Installing the Car Seat without the Base — For urban parents
Visual Installation Indicators
Every seat has some kind of level indicator on them to help you determine when the seat is properly installed. Some also include other indicators for things like determining if the anchor is sufficiently tightened.
A level indicator can look like a traditional level used in construction with liquid and a bubble, or it might just be a small ball that rolls and indicates the seat is level when it falls within a pre-marked zone in its path. No matter what the level looks like, it is important to use it directed because it helps indicate when you have the seat properly installed. Some less expensive seats might have a line on the side of the base that should be parallel with the ground beneath the car when installed correctly. The easiest way to use these is by standing back from the car to assess the line compared to the ground.
Being able to easily adjust the harness height on the seat can mean the difference between an infant that is secure in the seat, and one that is not. If a seat is easy to adjust as your baby grows, then there is less chance for error or avoidance.
The most difficult seats to adjust for a growing baby's height are those seats that require you to "rethread" the harness straps to make the adjustment. Rethreading means a car seat requires that you remove the shoulder straps from slots in the seat back to reinsert them at a different height slot to adjust for your growing baby's height. It can be an annoying process, but it isn't difficult if you adjust it with baby out of the seat because it only requires adjustment occasionally. The big downside of this is you may not notice it needs adjustment until your little one is in the seat and it can be a hassle to take a baby out of the seat to adjust the height. Some parents might even be tempted to wait to make the adjustment until the next trip. Unfortunately, this often leads to a cycle of forgetting and planning to do it the next time, over and over while baby rolling in a harness that doesn't fit.
Harness Tightening and Release
After the shoulder height is properly adjusted, the baby is in the seat and buckled in, you can tighten the harness by pulling on the trailing strap at the foot of the seat. This maneuver should be easy, and in theory, it is, but some of the tightening straps were harder to pull than others, and one had a totally different tightening system altogether.
Most of the seat harnesses we tested were loosened by pressing a button near the foot of seat. The buttons should be somewhat stiff to prevent little hands from making adjustments, but they shouldn't be so hard to push that an adult can't do it with one thumb. Some of the seats had buttons visible on top of the seat fabric. The remainder had the button hidden under padding or fabric.
The buckles on the seats
Weight of the Carrier
When doing research on the various car seats, it seems like every manufacturer claims they make the lightest seat. Weight is important because you might be carrying baby and seat from place to place, or required to lift baby up higher than your waist for some SUVs and trucks. Obviously, not all the seats can be the lightest, but a few were what we considered to be prohibitively heavy. The Evenflo Embrace is the lightest of the group at 7.76 pounds, but unfortunately, it didn't score well overall or in most metrics. The heaviest seat in the review is the Doona at 16.8 pounds, but it is also a stroller. Our Editors' Choice winners the Peg Perego Primo Viaggio and the Chicco Keyfit 30 were 9.58 and 10.06 pounds respectfully, while the Best Value seat, the Safety 1st, is 9.46 pounds.
Sometimes the difference is in the details, or the beauty and the devil depending on how you look at it. While many of the products sort of look the same, function the same, and even smell the same, the details of each help some stand apart from the pack. If a seat offers a feature that others don't or is giving attention to features that might increase potential safety, then we feel they should be recognized. In a product group so heavily regulated, it can be difficult to tell one seat from another or decide why one is better than the last, without looking at the features and functions that help them get ahead and stand out in a crowd.
Having a canopy is one feature that sets infant seats apart from convertible seats. All of the seats we reviewed offered some type of canopy, but they varied in size and additional features like a peek-a-boo window and ventilation or ability to be hidden or stretched the full length of the seat for added protection. We think the larger, the better for protecting little ones from the sun, and a peek-a-boo window might be nice to have, but it isn't a deal breaker if it doesn't. The Britax B-Safe 35 has the largest canopy in the group, but the UPPAbaby has a unique hard cover storage for the canopy when it isn't being used that helps make the seat's overall fit and finish impressive.
The Cybex Cloud Q crash test results with and without the load leg seem to indicate that a load leg offers an additional margin of safety to a seat. This product saw a significantly better head sensor score and similar chest score using the leg than without it.
If you are using the seatbelt instead of the LATCH Lower Anchors to attach the base, good LATCH storage is important to tuck it all away so that it doesn't get in the way when installing the infant carrier onto the base for a secure fit. Not all storage options are great, and we preferred the versions that keep the straps out of the way of any connection points. The UPPAbaby has nice retractable anchors that keep the straps ratcheted away, and the anchors tucked in side pockets. There is no chance these straps will impinge on the carrier's ability to attach to the base.
We suggest parents pick the car seat that best meets their needs first, then consider the strollers that are compatible with their seat as a 2nd step. The car seat selection is frankly a more important decision to ensure your infant's safety, and you are not likely to paint yourself into a corner when it comes time to pick a stroller.
Once you've narrowed down your seat choice, take a look at stroller compatibility as a final step. Our review of the most popular and highly regarded full-size strollers can help you look at options, and you might also look at our Stroller and Car Seat Combo review which looks specifically at which looks at which seats work best in combination with which strollers. Alternatively, a growing number of parents skip a stroller for the first 6-12 months by wearing their baby in a personal baby carrier. This travel option is easy, great for bonding with baby, decreases baby crying and distress, and keeps both hands free for shopping or pushing carts. You can check out our review of the best performing baby carriers, with detailed ratings and information on each.
There should be a location on each seat where you can store the seat manual for easy access on the go. This helps ensure you have the answers at your fingertips should a problem or question arise concerning installation or use. It is important to utilize this storage location as intended and to keep the manual where it is supposed to be. Some of these are in nicer locations than others with better accessibility or increased protection from spills and accidents that could make it hard or impossible to read (i.e. spit ups, and spills).
How do I decide which car seat is best for my baby?
With so many seat options and a variety of features to choose from, the task of buying a car seat can feel overwhelming. We've broken down the process into easy to consider steps that will help you decide which seat is best for your needs.
Step 1: Consider Where You Will Install the Seat
As we noted above, there are three ways to anchor the car seat, and each method relates to a different type of usage pattern.
If you live in a major city, and expect to take your baby in cabs or Uber, you will want to consider a car seat that is easy to install without the base, using the taxi's seat belt. Only about half the seats we tested performed well in this regard. Because this type of installation can be more challenging, we'd suggest urbanites closely consider the Peg Perego Primo Viaggio 4-35 and the UPPAbaby Mesa, both of which are exceptionally easy to install without the base.
Do you use taxis frequently and want a great car seat for pushing your baby around town? Consider the Doona that turns into a stroller and could make navigating city life with baby much easier.
Center Seat or Side?
The next key question is where the seat will be located in your car, and in the balance here is the question of whether the seat base is going to be anchored using the LATCH system (on a side seat location) or using the seat belt (in the center).
The safest location for the infant car seat is in the center seat, as accident research shows a 43% lower risk of injury for seats placed in the center. But, that center location will only be safe if you can properly anchor the seat securely and tightly. And, given that research shows more than 80% of infant car seats have at least one serious problem with installation, wise parents will take ease-of-proper installation seriously (as we do). About 39% of parents place the infant seat in the center location.
But, it is worth noting that most parents, 61% of us, place the infant car seat on one of the side seats, most often the right rear passenger side which allows the driver to see the baby more easily. The side seat is more convenient for loading baby in and out of the vehicle, is often the only option for multiple kids, and for those driving vehicles built after 2002, allows the use of the much easier and safer LATCH anchor system.
Most cars do not allow the use of the LATCH connectors in the center seat. So, if you are going to place the seat in the center, it usually means you are going to need to master the relatively difficult process of anchoring the base using the seat belt. Some car seat bases are much easier to install using the seat belt than others. We'd recommend you look at our review section on Ease of Installing the Base with the Seat Belt, and if you want to go for the center seat location, narrow your selection down to one of the seats that make this anchoring option simpler. This is another area where the Peg Perego Primo Viaggio 4-35 delivered standout performance and deserves a spot on your short list.
For those who decide to place the infant seat on one of the two side seat locations with LATCH, which is what we recommend due to the increased simplicity and more reliable installation process using LATCH, the quality options are wider. Many seats in our review were fairly easy to install using LATCH anchors, and 6 of 15 seats scored 7 of 10 or higher in our Ease of Installing the Base with LATCH tests. Three seats tied for first place with impressive 9 of 10 scores: the UPPAbaby Mesa, the Chicco Keyfit 30, and the Cybex Aton 2.
Making mistakes when installing a car seat or strapping baby is so common we have dedicated another article to this topic. It is crucial that a seat is installed correctly for it to work properly. Thus, we advocate that you consider ease-of-installation and ease-of-use as critical factors in your purchase decision.
Step 2: Consider Ease-of-Use
Getting the base installed safely is half the battle. But, the other element is the daily process of taking your baby in and out of the car seat and getting them safely harnessed in.
Not all seats performed equally on ease-of-use, and so if you emerged from Step 1 above with a handful of car seats on your short list, take a look at our ease-of-use ratings to narrow down further.
The top performers for ease of use, the Doona, Recaro Performance Coupe, and Evenflo Embrace seats, offered impressive performance with 8 of 10 scores, but were relatively weak in other areas, finishing below average in overall performance.
We'd suggest you look to the 2nd place finishers instead because on the whole they also ranked well. Three seats tied with 7 of 10, that all performed well across the board: the Chicco Keyfit 30, Chicco Fit2, Baby Jogger Go, UPPAbaby Mesa, and Peg Perego Primo Viaggio 4-35.
Step 3: Compare Crash Test Performance
Every seat in this review has passed the minimum requirements for crash tests as outlined by the Federal Government and thus offer a basic, safe, level of protection. But, some seats perform significantly better than others in crash tests and thus can be considered to offer an extra margin of protection.
Once you've narrowed to a handful of seats based on ease of use and installation considerations, we'd recommend you consider crash test results to further narrow down your selection. While many parents would consider crash test performance the most important factor, we feel that given that over 80% of parents improperly use or install the car seat, that you first consider installation and ease-of-use. It doesn't matter how safe a seat is if it isn't used correctly.
To evaluate the crash tests of each seat in this review we analyzed their crash test results to compare how well each seat did in relation to the required minimum score, as well as how each product performed compared to the competition. If you've narrowed down your list to a few finalists, choosing the seat which offers an extra margin of protection in crash test results can help you make your final selection. The Cybex Cloud Q is the Top Pick for Safety winner thanks to awesome crash test results. It isn't the best choice for all families, but if you want the absolute highest crash test score and aren't worried about price or other factors, it is a good choice.
Step 4: Consider Stroller Options
Choosing the right car seat is a more important decision than choosing a stroller. But, after you narrow down to one or two finalists for your car seat we suggest you consider compatible strollers. Take a look at our comprehensive review of the most popular and highly regarded full-size strollers, where you'll find details on which car seats are supported by which strollers. We also like the option of using a car seat frame stroller, which is lightweight and really convenient for the first 9 to 12 months while you baby remains in their infant seat. Check out our Stroller and Car Seat Combo Review for more info.
Also, keep in mind that an increasing number of parents delay buying a stroller for 6-12 months, and use a baby carrier instead. Wearing your baby can create a higher level of intimacy and bonding with your baby, and is fun for both parent and baby.
Step 5: Check the Expiration Date
Last, car seats expire. The foam used for crash impact absorption protection actually has a shelf life, and after a certain period should be destroyed and no longer used as a car seat. If you consider obtaining a used car seat, perhaps as a hand-me-down from a friend or relative, make sure it has not already expired, and that it won't expire in the 9 to 12 months you'll need it.
Buying your first car seat can be almost as overwhelming as the idea of having your first baby, but once you narrow down the options in a logical fashion it certainly doesn't have to be. With a manageable size list, you'll be cruising home with a new seat before you know it, and with any luck, you'll be doing it with a smile on your face.
Optional Reading: Car Seat Lingo
To help you delve deep into all things car seat, we want to provide a little insight into the terminology you might see or hear when reviewing information about them. This can help keep you on the right track and ensure that you really understand what you are reading so you can interpret the information as easily as possible. The terms below are those you might encounter in this article, other car seat related articles on our site, or on manufacturer websites. The terminology and definitions used here are taken from the National Child Passenger Safety (CPS) Certification Training Program manual, some definitions may have been slightly altered to increase readability, but the intent/meaning remains the same.
- FMVSS 213 — Federal Motor Vehicle Safety Standard #213. This is the safety standard that details the safety guidelines car seats need to meet or exceed to be sold. Every car seat on the market has met or exceeded these safety standards. On some level, no matter which seat you purchase, you are getting a seat that has already passed relatively stringent guidelines.
- Buckle — Where the harness system connects and locks in place.
- Harness — The harness consists of the straps that keep the child in the car seat and spread out crash forces. Two harness types that meet FMVSS 213 requirements: 5-Point: Harness has five points of contact that includes one over each shoulder, one on each side of the pelvis, and one between the legs with all five coming together at a common buckle. 3-Point: Harness has three points of contact that includes two shoulder straps coming together at one buckle in the shell or on a crotch strap. NOTE: NOT to be confused with a 3-point (lap-and-shoulder) vehicle belt.
- Retainer Clip — Plastic buckle or clasp that holds shoulder straps together over the child's chest and should be positioned at the child's armpit level.
- Harness Adjuster — The part used to tighten or loosen the harness.
- Harness Slots — Parts of the car seat where the harness goes through the seat shell for shoulder height adjustment or crotch strap adjustment related to the height of the child.
- Shell — Molded plastic and/or metal structure of the car seat or booster seat that is typically located on the outside of the seat or structurally inside covered by the seat padding.
- Seat Padding — Padding that covers the shell and frame of the seat, typically consisting of dense foam.
- Padding — Additional padding or inserts some manufacturers provide to increase child comfort that has been crash-tested with the seat. You should never use padding with your car seat that did not come with that seat. It could alter the seat's performance during a crash or cause potential injury.
- Level Indicator — The part of the car seat that helps identify correct rear-facing installation angles. It can be a green to a red indicator, a ball level, or more of a traditional bubble level.
- Belt Path — The location on a car seat where the seat belt or lower anchor connector is placed to secure car seat to the vehicle.
- Recline Adjuster — This feature allows car seats to be reclined for rear facing seats, and semi-reclined or upright for forward-facing use.
- Splitter Plate — A metal plate that connects two ends of the shoulder harnesses to a single piece of webbing used for adjustment; found on the back of the seat.
- Lock-Off — Built-in belt-locking feature on a car seat that works with certain types of seat belts based on the same concept as a locking clip.
- Locking Clip — A locking clip holds the car seat in the proper position during normal driving when no other locking mechanism is available.
- Lower Anchor Connector — Connectors attached to the car seat that are used in place of the vehicle seatbelt to secure the car seat or booster seat to the vehicle utilizing U-shaped hooks located between the seat back and bottom cushions on the vehicle. These connectors can be flexible (attached to a belt) or rigid (stiff connectors with no belt).
- Tether Connector — A piece of belt webbing with a hook connector that anchors the top of a car seat to the vehicle and keeps restraint (car seat) from tipping forward on impact. It can provide extra protection, and it is most frequently found on forward-facing seats.
- Detachable Base — This is a separate car seat base that is installed in the vehicle, while the car seat carrier portion of the seat can be removed from the base.
- Adjustment Foot — A part of the detachable base that can be adjusted to help a rear-facing car seat to be installed at the correct angle.
- Carry Handle — The handle attached to a rear-facing car seat that can be used to carry the seat with or without a child in it.
- Foot Prop or Load Leg — Pole or leg that extends from the base of a rear-facing car seat that is used to reduce excessive forward and downward rotation of the seat in the event of a crash.
- Anti-Rebound Bar — This is a hard bar or high back on some rear-facing car seats that may help to reduce movement of the car seat towards the rear of the vehicle seat in a crash. This decreases the rebound effect of the seat.
- LATCH Guides — These are plastic pocket squares that come with some car seats that when used help create an opening between the back and seat cushion to give better access to the U LATCH points on the vehicle.