Chicco Fit3x vs. Graco SlimFit3 LX: Ultra-Slim Car Seat Comparison
The Chicco Fit3x ClearTex and the Graco SlimFit3 LX are two of the narrowest car seats on the market. Whether you need seats that fit side-by-side for a 3-across setup or something ultra-narrow to install next to a folding vehicle seat that provides access to the 3rd row, both of these seats should be at the top of your list. At first glance, they appear very similar in size and specs. However, there are a few key differences that may make one a better choice for your family’s needs.
Chicco Fit3x (left) and Graco SlimFit3 LX (right)
We have extensive experience with both Fit3x and SlimFit3 LX. We understand how they’re similar and how they differ. If you’re interested in the specific measurements, we have a chart at the bottom of this article. Once you have all the info, you’ll have a better idea of which seat is best for you.
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FIT3X & SLIMFIT3 LX SPECS
Chicco Fit3x
Rear-facing: 5-40 lbs., up to 43”
Forward-facing: 26.5-65 lbs., 38-54”
Belt-positioning booster: 40-100 lbs., 44-57”, age 4+ yrs.
MSRP $229
Graco SlimFit3 LX
Rear-facing: 5-40 lbs., head must be 1” from top of headrest, 49” or less
Forward-facing: 26.5-65 lbs., 49” or less
Belt-positioning booster: 40-100 lbs., 43-57”, age 4+ yrs.
MSRP $299
Similarities
Identical external widths (16.7” wide)
Identical interior shoulder room
Identical seat depth for leg/thigh support
Nearly identical top harness slots (Fit3x is slightly taller)
Nearly identical shoulder belt guide heights for belt-positioning booster use
Both have lockoffs for a seatbelt installation, but Fit3x has 2 lockoffs, one for RF and one for FF, whereas SlimFit3 LX only has a single lockoff in the FF beltpath
Both can be installed rear-facing with LATCH up to the seat’s RF weight limit of 40 lbs.
Both have 10-year lifespans before they expire
When forward-facing, both are mostly compatible with angled, non-removable vehicle head restraints. However, no single car seat works in every vehicle or seating position, so our best advice is always to try before you buy. If that’s not possible, make sure you understand the return policy before you make your purchase. Amazon, Target, and Walmart all have excellent return policies if the seat doesn’t work out for any reason.
Differences
Price ($229 for Fit3x vs. $299 for SlimFit3LX)
Fit3x sits lower and is 1” shorter overall, but the maximum harness height is ½“ taller.
Fit3x features a “side support” hip bolster insert that is required for children under 40 lbs. Once that bolster is removed, Fit3x is wider in the hip area.
Fit3x has a flex-forward buckle cover, which pops the buckle forward and out from under the child when loading.
Chicco uses flame-retardant-free fabrics and foams; Graco treats all current SlimFit3 LX covers with flame-retardant chemicals.
SlimFit3 LX has push-on LATCH connectors; Fit3x has modified hook-style LATCH connectors, which they call “Mini-Grip” connectors. Thankfully, the LATCH strap adjuster release mechanism on the Fit3x works beautifully (Graco should take notes!), and that makes a huge difference when you need to remove the hook connectors from the lower anchors in the vehicle.
SlimFit3 LX has 2 optional external cup holders; Fit3x has 2 integrated “cup folders” that simply fold in if you need that extra room on one or both sides.
Both seats max out at 40 lbs. rear-facing, but the RF height limits differ enough that a lightweight child who is also very tall may fit longer rear-facing in the SlimFit3Lx due to its generous height limits. We go more in-depth on the topic of height limits below.
SlimFit3 LX has 4 recline positions (2 for RF, 2 for FF); Fit3x has 6 recline positions that can be used to achieve the appropriate recline angle for RF or FF.
SlimFit3 LX takes up a little less room front-to-back when rear-facing because it’s positioned at a more upright angle (pics below).
Fit3x offers more recline when rear-facing, which is preferable for babies under 1 year old, and it may reduce head slump when sleeping.
Chicco Fit3x (left) vs. Graco SlimFit3LX (right)
As you can see in the side-by-side picture below, the rear-facing recline angle on the SlimFit3 LX is more upright than the Fit3x, which means for newborns and younger babies, the Fit3x is generally a better choice.
The tradeoff is that Fit3x will take up a little bit more space from front to back. If you need the full recline for a baby under 12 lbs., it takes up even more room, but that will be a short-term situation because babies grow quickly. In the Tesla Model 3 pictured below, achieving the maximum allowable recline angle for a newborn (as per the angle indicator) required adding a foam pool noodle (with specific permission from Chicco).
Maxximum recline position in Tesla Model 3
Maximim upright position allowed in Tesla Model 3
Choosing Between Fit3x & SlimFit3 LX
We can’t decide for you! 😃 This decision may come down to price, whether FR-free fabrics are important to you, or if your backseat is very compact front-to-back and you really need the most upright rear-facing seat.
Another factor to consider is the different height limits. Chicco Fit3x has a rear-facing height limit of 43” while the Graco SlimFit3 LX technically allows children up to 49” in the rear-facing position as long as their head is at least 1” below the plastic headrest adjustment handle (and they are still under 40 lbs.). Almost all children will outgrow a Graco SlimFit3 LX rear-facing by weight before maxing out the very generous height limits. With the Fit3x, it’s a toss-up. Some kids will hit 40 lbs. before they reach 43“, and vice versa.
Forward-facing, the Chicco seat appears to have the height advantage because its limit is 5” taller than the Graco seat (54” vs. 49”). However, the maximum harness height measurement for both seats is very similar (17 ½ for SlimFit3 LX and 18” for Fit3x). It's important to understand that most children will outgrow a forward-facing car seat with a 65 lb. limit by height, and specifically by “seated height” when their shoulders are above the top harness height setting. In reality, your child may outgrow either seat before they even reach 49”, and that may render the 54” FF height limit on the Chicco irrelevant.
Generally speaking, both seats should accommodate most kids rear-facing up to age 4, and up to age 6-7 forward-facing in the harness. If you’re committed to rear-facing for as long as possible and you think it’s likely that your child will hit 43” way before reaching 40 lbs., the SlimFit3 LX has the advantage thanks to its very generous rear-facing height limit.
2018 Subaru Outback: Chicco Fit3x RF/Graco SlimFit3LX FF
2024 Nissan Rogue: 3 across with Peg Flex Booster/RF SlimFit3LX/FF Chicco Fit3x
Once again, the key differences are - Fit3x has all FR-free fashions, a rear-facing lockoff for seatbelt installations, a more typical rear-facing recline angle, and a lower price. SlimFit3 LX is more upright when rear-facing, has push-on LATCH connectors, and lacks any type of side support bolsters.
Overall, they’re both great seats that are relatively easy to install with either LATCH or the seatbelt. However, since neither seat has a belt-tensioning feature, their installations do require some effort to get the seat secure. Neither seat would be ideal for someone who struggles to get an acceptable install without some type of built-in mechanical advantage.
| Model & Feature | Measurements |
|---|---|
| Fit3x Top Harness Slots | 18" |
| SlimFit3 LX Top Harness Slots | 17 ½" |
| Fit3x Shoulder Belt Guide | 19 ½" |
| SlimFit3 LX Shoulder Belt Guide | 19 ¼" |
| Fit3x Inside Shoulder Width | 13 ¼" |
| SlimFit3 LX Inside Shoulder Width | 13 ¼" |
| Fit3x Hip Width with Side Supports | 9 5/8" |
| Fit3x Hip Width without Side Supports | 12 ¾" |
| SlimFit3 LX Hip Width | 11 ½" |
| Fit3x Seat Pan Depth | 13" |
| SlimFit3 LX Seat Pan Depth | 13" |
| Fit3x Shell Height | 28 ½" |
| SlimFit3 LX Shell Height | 29 ½" |
