2019 Safety 1st onBoard 35 LT Infant Carseat Review

2019 Safety 1st onBoard 35 LT Infant Carseat Review

If you’ve driven around for any period of time, you have probably seen a sign on a car signaling that a baby is in the back seat. The most iconic of these, which also happens to be the original, is the yellow diamond Baby On Board sign by Safety 1st. Not only did this sign give birth to the rest of Safety 1st line, which has such a wide array of products that it can be found in the home of almost every family with an infant, but it’s also given its name to a new high quality, affordable infant seat- the Safety 1st onBoard 35 LT. Do not confuse this seat with the other Safety 1st onBoard infant seats on the market. The “LT” model is an entirely different seat with its own base – it is NOT compatible with the original onBoard or onBoard Air model bases.

Monument Juniper Pop Pebble Beach Niagara Mist

OnBoard 35 LT Height & Weight Limits:

  • Rear-facing only 4-35 pounds, 19-32 inches and child’s head is at least 1 inch below the top of the seat

OnBoard 35 LT Overview:

  • The onBoard 35 LT is one of the lightest rear-facing-only infant car seats with a smooth and comfortable carry handle
  • 4 harness heights to provide an excellent fit for a variety of different sized babies
  • 3 crotch strap/buckle positions with newborn routing to fit even small newborns
  • Newborn support inserts with separate head and body cushions
  • Cover is machine washable AND dryer safe!
  • FAA approved for use in aircraft
  • On CarseatBlog’s Recommended Infant Carseats for Preemies & Multiples
  • 8 year lifespan from date of manufacture before expiration

The first thing I noticed when I unboxed the seat were the labels. Safety 1st has clearly spent a lot of time thinking about and designing their labels and the outcome is great. Their labels are clear, concise and well placed and I could install and use the seat without ever cracking open the manual because of these labels (I’m not recommending this, but for those people who won’t read a manual regardless, this is great!). There’s even a label with a QR code so you can get information instantly on your phone. The onBoard 35 LT base has labels for where the belts go, as well as labels for baseless installation. I was generally impressed with the thoughtfulness Safety 1st clearly had when designing this component of their seat.

OnBoard 35 LT Measurements:

  • Harness slot heights: 5.5”-11.5”
  • Crotch strap/buckle positions: 3”, 4.5”, 6”
  • Internal shell height: 19.5”
  • Width of base: 15.5”
  • Length of base: 23.5”
  • Width of carrier at widest point: 17.25”
  • Carrier weight: 7.9 pounds


The base has 2 recline options: the foot can be extended or not, depending upon the angle of the vehicle seat. To determine if the angle is correct, there is an angle line on the carrier that must be parallel to the ground. Unfortunately there’s no range, just a single line, but the seat isn’t very large front to back, and it fit easily at the proper recline level. If the recline foot isn’t enough for your car, a rolled towel or foam pool noodle is allowed. The path for the lower anchors/seat belt was clearly labeled and easy to access. The handle must be in the upright position when in the vehicle.


The installation with lower connectors is very straightforward and simple. The lower connectors are hook-on style and the belt of the LATCH strap lays across the top of the base. It’s pretty quick and easy to tighten, with a button to push to assist in loosening. Sometimes it can be tough to loosen and remove hook-on style lower anchors, but this wasn’t an issue with the onBoard base. It was easy to install, easy to tighten and get a rock solid installation and it was equally easy to loosen and remove the base. I was pretty impressed considering how many seats have moved onto far more complex bases, that this very straightforward base installed as well as it did.


The seatbelt installation was similarly simple with my lap and shoulder belt. The belt routes under the two arms of the base and lays across the same path as the LATCH belt. There’s no lockoff, so the belt has to be switched into the locking mode and then manually tightened. I was worried, since the base is so light and doesn’t have a lock off that the base may tilt slightly, but the design of the base seems to address this, as there was absolutely zero tilt to be seen. Once the carrier was clicked in, I found the seat to be really reasonably sized; I didn’t need to move the front seat up at all from it’s normal position to accommodate the onBoard and it didn’t encroach laterally into the seat next to it either. I would say that this is a pretty great option for a smaller back seat.

Safety 1st does not allow the onBoard 35 LT to be installed with inflatable seat belts. Use LATCH instead.


The belt path for the baseless installation is slightly covered by the seat cover, but well-labeled in case it’s not well-known by the installer. As with most seats, only the lap portion of the belt goes through the guides, and then the belt must be locked and tightened to secure the seat. Since the angle indicator is on the carrier you use the same angle indicator as if you were installing with the base. My car didn’t require it, but if needed, a rolled towel or foam pool noodle can be used to maintain the proper angle when installing baselessly.


I only had one baby to try this with and when we tried it out initially, Ben was 2.5 months old, 13.5 pounds and 23” inches long. He fit with plenty of room below and above and I can say confidently that he would’ve fit well at birth even though he was 19”, which is the lowest height allowed. I do think he would’ve fit better without the infant insert, but I only managed to snap a picture without the lower insert, not realizing that when you remove the lower insert, you must also remove the head support and I don’t want to post a picture with improper use (read your manuals, folks! Even CPS techs make these mistakes!). We tried the seat again with Ben, who is now 5 months, 17 pounds and probably around 26″. He still had a great fit with plenty of room to grow.

There appeared to be ample harness for an older baby, and the internal height of the seat was more than adequate to get a child to the stated height limits of the seat, probably even beyond (but don’t do that. Follow the rules.)

Cover and Cleaning:

The cover is easily removed if you follow the directions in the manual and not only is it machine washable, it can also be dried in the dryer! As the parent of a baby who spits up in his car seat every. single. day. I can’t tell you how much I love this. I hope more companies make this happen.

FAA Approval, Lifespan, Crash Guidelines:

  • FAA approved
  • 8 year lifespan
  • Must be replaced after any crash

Stroller Compatibility/Travel Systems:Smooth Ride Travel System

The onBoard 35 LT is compatible with any Safety 1st strollers that have the QuickClick attachment. The onBoard 35 LT is also available as a part of the Smooth Ride travel system.

Safety 1st onBoard 35 LT Advantages:

  • 4 harness height slots, 3 crotch strap positions
  • Plush newborn body and head insert
  • Machine washable AND dryer safe seat cover/padding
  • Fits small newborns and up to average 1 year olds easily and comfortably
  • The Juniper fashion which we had was gorgeous and I got multiple comments on it
  • Labels on the seat are outstanding: clear, concise and well placed, including one with scannable QR code
  • Manual is well written and easy to navigate
  • Extremely lightweight, narrow and relatively compact for a rear facing only seat
  • On CarseatBlog’s Recommended Infant Carseats for Preemies & Multiples
  • The price on this seat is really, really reasonable, especially given the quality, at just $99 on Amazon.


In fairness to the seat, these aren’t really universally problematic issues, they are just things that could be an issue to some consumers.

  • Only one level line for the angle of the seat, meaning it cannot be more upright as baby grows
  • Older style hook lower anchor connectors
  • No seat belt lockoff on base


In the world of rear facing only seats, the current trend seems to be moving towards expensive seats with a lot of bells and whistles. The onBoard 35 LT manages to stay competitive in the market with these pricier seats because of the quality of the seat and its thoughtful and functional design. If I hadn’t seen the price myself, I would’ve expected the seat to be substantially more expensive than it’s sub-$100 price tag. I wouldn’t hesitate for a second to recommend this seat to new parents because of its ease of use, outstanding labeling and ease of use, as well as its excellent fit from newborn to age 1.


Thank you to Safety 1st for providing the onBoard 35 LT sample for this review. No other compensation was provided. All opinions expressed are those of CarseatBlog.


  1. Trev.R December 3, 2020
    • Kecia December 3, 2020