Graco SlimFit 3-in-1 VS Extend2Fit – Comprehensive Comparison

What Is the Difference Between Graco Extend2fit And Slimfit?

The Graco Slimfit 3-in-1 and Extend2Fit are close contenders in the Graco family, but making a choice could be dicey because of their comparable features.

However, the significant differences which distance these two models are the size/dimensions. What then are the other differences that could influence your buying decision for either of the seats?

Read on to learn more on the difference between the Slimfit 3 in 1 vs Extend2Fit, which covers the following;

  1. Specifications
  2. Features
  3. Ease-of-use rating
  4. Crash tests
  5. Other parents’ feedback assessment

This comparison of the Graco Slimfit vs Extend2Fit will help you make an easy decision when choosing between these seats. This comparison also includes the SlimFit3 LX 3-in-1.

slimfit vs

Specification Comparison: Graco SlimFit 3-in-1 VS Extend2Fit

Product dimension (inches)

SlimFit 3-in-1 – 21.5D x 25.5H x 19.9W (inches)

SlimFit3 LX 3-in-1 – 20.7D x 24.5H x 16.7W (inches)
20.75D X 24.5H X 19.0W
Product weightSlimFit 3-in-1 – 19.47 lbs. SlimFit LX 3-in-1 – 19.2 lbs.20.61 lbs.
Seat modes3-in-1Platinum
Extension panel (extra legroom)
Recommended weight range5 – 100 lbs.4 – 100 lbs.
Recommended height limit57 in57 in
Rear-facing weight limitmin. 5 lbs.; max. 40 lbs.min. 4 lbs.; max. 50 lbs. (extended usage in RF)
Rear-facing height limitmin. 19 in.; max. 40 in.min. 19 in.; max. 49 in. (extended usage in RF)
Forward-facing weight limitmin. 22 lbs.; max. 65 lb.min. 22 lbs.; max. 65 lb.
Forward-facing height limitmin. 29 in.; max. 49 in.min. 29 in.; max. 49 in.
Highback booster seat weight limitmin. 40 lbs.; max. 100 lbs.min. 40 lbs.; max. 100 lbs.
Backless booster seat weight limit

4-in-1 min. 40 lbs.; max. 120 lbs.

Booster seat height limitmin. 43 in.; max. 57 in.min. 43 in.; max. 57 in.
ParentingWithHumility Rating8.0/108.5/10

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NHTSA Ease-of-Use Rating

The National Highway Transport and Safety Agency (NHTSA) provides a simple evaluation of car seats based on how easy it is to use different features in different modes. There is an overall ease-of-use rating for each seat to help you make a quick and informed decision.

This rating is based on four categories:

  1. Evaluation of Instructions
  2. Vehicle Installation Features
  3. Evaluation of Labels
  4. Securing the child


  • 5 Stars = Excellent features
  • 4 Stars = Above-average features
  • 3 Stars = Average features
  • 2 Stars = Below-average features
  • 1 Star = Poor features
  • N/A = Does not contain any features that require a rating
Rear-facing – overall rating⭐⭐⭐⭐⭐⭐⭐⭐
Forward-facing – overall rating⭐⭐⭐⭐⭐⭐⭐
Booster – overall rating⭐⭐⭐⭐⭐⭐⭐⭐

General Features Comparison: – Differences and Similarity Highlight

Safety Features

Safety featuresSlimFitExtend2Fit
Side Impact Protecttion
5-point Harness System
Exceeds federal safety standards
Crash tested

Extra tests (frontal, side, rear-impacts, and rollover crash tests)

Graco ProtectPlus Engineered

Extra tests (frontal, side, rear-impacts, and rollover crash tests)

Graco ProtectPlus Engineered

IIHS rating for Booster seat mode✔✔ Best Bet✔✔ Best Bet

Installation Features

Installation featuresSlimFitExtend2Fit
LATCH/LUAS/ISOFIX system✔ + InRight™ LATCH attachment – easier installation with LATCH✔ + InRight™ LATCH attachment – easier installation with LATCH
Safety seat belt
the SlimFit3 LX features the integrated belt lock-off system

the 4Ever Extend2Fit 4-in-1 features the Integrated belt lock-off – easier installation with belt

Ease-of-Use Features

Ease-of-Use featuresSlimFitExtend2Fit
Fits 3 Across Back Seat
Extension panel (extra legroom)
Harness storage
Harness holders
(to hold the harness back while getting your child out of the seat)
Only for the SlimFit3 LX 3-in-1
Harness adjustment✔ Simply Safe Adjust™ Harness System✔ Simply Safe Adjust™ Harness System
No-rethreading of harness
Machine washable
Car seat cover✔ Easy to remove

✔✔ the SlimFit3 LX features the Rapid Remove cover (easier)
✔ Easy to remove
Headrest adjustment10 positions10 positions
Recline positions4 positions6 positions
Recline Level IndicatorBubbleBubble
Rear-facing recline position
  • Position 1 – best for newborn
  • Position 2
  • Position 1 – best for newborn
  • Position 2
  • Position 3
  • Position 4
Forward-facing recline position
  • Position 3
  • Position 4
  • Position 4
  • Position 5
  • Position 6
Booster seat recline position
  • Position 4
  • Position 6 
Removable cups2 (round and rotatable)2 (square)

Comfortability of a Child

Soft plush fabric
Removable newborn inserts22
Breathable Mesh AirFlowAvailable (SlimFit3 LX 3-in-1 ONLY)

Longevity, Suitability, and Compatibility

Longevity & Suitability featuresSlimFitExtend2Fit
Expiration10 years (from Date of Manufacture)10 years (from Date of Manufacture)
FAA Approved (RF & FF only)
Suitable country by lawUSAUSA
Vehicle compatibility

Compatible with small, compact, mid-size, full-size, vans and SUVs vehicles

Compatible with compact, mid-size, full-size, vans and SUVs vehicles

Miscellaneous features

Available colors58
Country of OriginChinaChina
Body frameworkSteel-reinforced frameSteel-reinforced frame

Detail Analysis of Both Seats – Which is the Winner? – Helping You Make a Decision

Going through the table, you’ll find out both seats are nearly at par. However, some differences distinguish both seats from each other, but one doesn’t really stand out. At the end of the day, personal preference will play a major decision-making factor for you.

The significant differences between the Graco Extend2Fit vs SlimFit:

  1. Dimension: The SlimFit (SlimFit3 LX 3-in-1) is slimmer than the Extend2Fit by about 3 inches. While the SlimFit 3-in-1 measures 19.9 inches with the cups (0.9 inches more than the Extend2Fit), you can rotate the cups and save 10% more space (becomes 17.91 inches); however, you can use the cups when rotated.
    Nonetheless, both seats will fit three across in the back seat for mid-size vehicles, but the SlimFit3 LX 3-in-1 will fit three across perfectly in small cars.
  2. Extension Panel and Extended Usage in RF: These features and differences earned the Extend2Fit its model name. The Extend to fit car seat features an extended usage of 4 lbs – 50 lbs when rear-facing and comes with an additional 4-Position extension panel for extra 5 inches of legroom as your child grows (in rear-facing ONLY). The Graco SlimFit lacks these features.

Other differences are covered in detail according to the following category:

Specification Comparison

This section will cover all on product dimensions, weight, seat modes, weight, and height limits.

Product Dimension

The product dimensions have been highlighted earlier as the major differences in both seats.

While the Slim3 LX 3-in-1 is more compact than the Extend2Fit, the SlimFit 3-in-1 is about the same width. However, both seats will fit 3 across the backseat in nearly all vehicles.

If you have a small car and would want to use three car seats in the backseat, then the Slimfit LX will be the ideal seat.

If you ride a mid-size vehicle or just need an additional car seat for the backseat, then you can conveniently go for either the Slimfit 3-in-1 or the Extend2Fit.

Seat Modes, Weight and Height Limits

This is where another major difference lies between these models.

The SlimFit car seat comes in just one mode – 3-in-1. In contrast, the Extend2Fit comes in four series as three modes – Platinum (3-in-1), 2-in-1, 3-in-1, and 4-in-1 (4Ever Extend2Fit 4-in-1).

The Extend to fit features an extended usage in rear-facing (4 lbs – 50 lbs), while the 4Ever Extend2Fit 4-in-1 features an additional backless booster seat mode with weight and height limits of 120 lbs. and 57 inches respectively.

In comparison, the SlimFit can be used for infants weighing 5 lbs up to 40 lbs in rear-facing. The slim fit stops at highback booster seat – 100 lbs weight limit.

Features Comparison

This aspect covers on safety, installation, ease of use, comfortability for a child, and how long either seat lasts.

One thing to note in this comparison is that all features in both seats are nearly similar.

Safety Features

In terms of safety, all car seats are generally safe. Car seats are manufactured to meet stringent federal safety standards before being released to the market. However, manufacturers go overboard to add more safety features.

The Graco Slimfit and Extend2Fit carry the same safety features;

  • Both seats feature Side Impact Protection,
  • Include 5-Point Harness System,
  • Exceed Federal Safety Standards,
  • Are rigorously Crash Tested in all crash types (frontal, rear, side, and rollover crashes), and
  • Both have the same IIHS Rating for Booster Seat mode – BEST Bet.

Installation Features

Car seats can be annoying when it comes to installing them. However, Graco is kind enough to include special features that make it relatively easy to install your car seat by either the LATCH system or seat safety belt.

Both seats are similar in terms of the installation features.

Both models feature the InRight™ LATCH attachment, which makes installing with the LATCH system easy.

While the safety belt method for the basic lines of both models does not feature the integrated belt lock-off system, the upgrade of both models (SlimFit3 LX 3-in-1 and 4Ever Extend2Fit 4-in-1) features the integrated belt lock-off.

Ease-of-Use Features

Both seats are very easy to use with similar basic features such as no-rethreading of harness, easy to adjust harness and headrest together in 10 positions, and machine washable seat covers. Nonetheless, there are slight differences in the following features;

Harness holder: the Extend2Fit features a harness holder that allows you to get your child out of the seat quickly; however, only the SlimFit3 LX 3-in-1 has this feature.

Rapid Remove Cover: a feature that allows you to remove the seat cover easily in under 1-minute without uninstalling the car seat is absent in the basic line of both models. However, the SlimFit3 LX 3-in-1 and 4Ever Extend2Fit 4-in-1 carry this feature.

Recline Positions: The Graco Slim fit allows reclining in just four positions, while the Extend to fit allows up to six positions. This difference is quite significant if you seek extra comfort for your child. However, parents report that it is just okay for them, while parents who have used other Graco models with more recline positions complain of this.

Removable Cups: both seats feature two removable cups, but their shape and integration are different. While the Extend2Fit features square cups, which some parents do not like, the SlimFit’s are round and rotatable (in SlimFit 3-in-1) and save 10% more on valuable space.

Comfortability of a Child

Both seats are very comfortable for a child, featuring soft plush fabric and a well-padded cushion for extra comfort.

However, the upgraded line of the SlimFit (LX) features breathable mesh AirFlow channels to provide improved ventilation for your child.

Nonetheless, both seats come with two newborn inserts (head and body support) for extra comfort.

Parents attest to the comfort of either of the seat.


All Graco car seats feature a reinforced steel frame, which gives their car seats more strength for more extended durability.

Both seats have a lifespan of 10 years. This means their expiration date is ten years from the date of manufacture. The sticker that carries the DOM can be found on the side of the car seat.

FAA Approved

Both models are FAA approved and can be used on only forward-facing airplane seats in either rear-facing or forward-facing. Both seats are not approved for use in booster mode as airplanes do not have shoulder belts.

Final Thoughts: Decision-Making Points

In my Extend2Fit review, I rated the seat 8.5, while the Graco Slimfit review had an 8.0 based on their individual features and versatility in model lines.

However, you’ll see they both had a high rating. So far from this comparison, we can see the Graco Extend2fit vs Slimfit are close in features.

Nonetheless, the major difference is the extended usage in rear-facing, 4 lbs. – 50 lbs. for the Extend2Fit, and the extra slim width, 16.7 inches, for the SlimFit3 LX. Therefore, these will be the key decision-making factors for you to consider.

If you have a very small car and need to fit three seats in the back seat, you should consider the SlimFit3 LX 3-in-1. If you have a mid-size car and need a third car seat or two more car seats for your vehicle, you should consider the Extend2Fit or the SlimFit 3-in-1.

However, depending on your state car seat law, or if you want to follow the AAP recommendation religiously (that a child should ride rear-facing for as long as possible, up to 2 – 4 years), you’ll want to consider the Extend2Fit car seat.

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