Britax Poplar Vs. Poplar S | What’s The Difference?

If you’ve ever installed a convertible car seat and walked away sweating, you’re not alone. Between tight backseats, awkward angles, and figuring out which features actually matter, choosing the right car seat can feel like a full-time job. That’s where the Britax Poplar lineup comes in.

The Britax Poplar offers flexibility for growing toddlers, while the Poplar S is the better pick if you want all the newborn-friendly features included from day one.

Britax has two versions of the same great solution: the Poplar and the Poplar S. Both are compact, thoughtfully designed convertible seats that shine in tight spaces, but they come with a few key differences that could impact what works best for your family.

In this post, I’ll walk you through what both versions offer, how they install, and what sets them apart. Whether you’re focused on fit, features, or flexibility, the Poplar lineup is all about making everyday life a little easier.

Hi, I’m Sam! I’m a Certified Child Passenger Safety Technician (CPST) and a mom of four. I help families feel confident, safe, and informed when it comes to car seats and family vehicles.

For more information on other convertible car seats Kelly loves, check out the post: Best Convertible Car Seats!

Britax Poplar Height and Weight Limit

The Britax Poplar accommodates rear-facing children up to 50 lbs or 49 inches. With a top harness height of about 17”, it suits most kids, though taller torsos may max it out sooner.

Why The Britax Poplar Stands Out

The Britax Poplar and Poplar S stand out for three reasons: a compact fit, hassle-free installation, and fabrics that are easy to clean.

• It’s narrow and space-saving.

  The Poplar comes in at just 17” wide, which makes it one of the slimmest convertible seats on the market. If you’re trying to fit three across, this could absolutely be a game changer. And even if you’re not, having a narrower seat just gives everyone a bit more room to breathe.

• ClickTight makes installation EASY.

ClickTight (Britax’s built-in lock-off system) takes the guesswork out of getting a tight, safe install. No sweating or tugging required.

How it Works: Just open the seat’s base, thread the seat belt through the path, and close the base until it clicks. That “click” locks and tightens the belt for you! Remember, you’ll only need to do this when installing the seat - not each time you buckle in your child.

Kelly breaks down her full take on the Poplar in this reel, demos exactly how the ClickTight works, and shares why it's one of her go-to features for families running multiple car seats.

• Ideal for families who switch seats between cars.

 It’s consistently easy to install, so if you’re moving seats between cars or caregivers, it holds up beautifully.

• Compact design supports extended rear-facing—without sacrificing front-seat legroom.

Set to its most upright rear-facing angle (allowed for kids who meet the minimum age/weight), the Poplar fits well behind the passenger seat, even in small cars. It accommodates rear-facing children up to 50 lbs or 49 inches. With a top harness height of about 17”, it suits most kids, though taller torsos may max it out sooner.

• SafeWash fabric is machine wash and dry safe.

Britax’s SafeWash fabric is free of added chemical flame retardants, making it machine wash and dry safe. Plus, newer models now include removable harness pads for easier cleaning—a small but sanity-saving update.

Poplar vs. Poplar S: What’s the Difference?

Britax Poplar S

• Includes ReboundReduce anti-rebound bar (already installed)

• Comes with extra infant inserts for a better newborn fit

• Features more muted or jewel-toned fabric options and the Britax famous Cowmooflage

• Ideal if you're using it from birth or want all the extras included up front

Britax Poplar

• Does not include an anti-rebound bar (which is a safety feature that helps reduce movement in a crash by limiting the backward motion that can happen after a forward impact). However, you can purchase it separately if you’d like that added protection.

• Great for toddlers or families who don’t need infant-specific features

• Slightly more budget-friendly

• Same slim profile and easy installation as the Poplar S

Bottom Line:

• Go with the Poplar if you want flexibility and don’t need newborn features

• Choose the Poplar S if you want everything included and plan to use it from day one

A Few Things to Keep in Mind…

It’s a heavy car seat.

The Poplar weighs just over 26 pounds, which means it’s solid and sturdy, but not something you want to carry through an airport without help. If you’re flying with it, I highly recommend using a travel cart. I use the Britax Car Seat Travel Car, and it makes a huge difference. You just strap the seat on, pull it like a rolling suitcase, and go. Trust me, it’s worth it!

Not a perfect fit for forward-facing in every car.

When used forward-facing, the Poplar might not work in vehicles that have angled, non-removable headrests (like some Volvos or Jeeps). These headrests can push the car seat out of position or create a gap behind it, which isn’t allowed.

If you’re unsure whether it will work in your car, ask ChatCPST! ChatCPST connects you directly with me, a certified child passenger safety technician, and I’ll help you check compatibility and make sure your install is both safe and correct.

Don’t guess on car seat safety. Get trusted advice tailored to your car and car seat needs today.

It installs best with the seat belt.

You can install the Poplar using LATCH anchors (those lower hooks in your car), but the seat really shines when you use the seat belt. Why? Because the built-in belt tensioning system gives you an easy, secure, and super solid install without the struggle. It’s honestly one of the easiest seat belt installs I’ve ever done, no sweating or second-guessing required!

But keep in mind, it’s not ideal in vehicles where you want to use LATCH to take advantage of third row access with car seat friendly tilt.

So, Is The Britax Poplar Worth It?

For most families, absolutely. Between the slim profile, generous rear-facing room, easy ClickTight installation, and machine-washable fabric, the Britax Poplar (and Poplar S) really delivers. It’s not the lightest seat out there, and it may not be the best fit for super-tall kids, but overall, this (almost) unicorn of a carseat is a solid choice for everyday use!

Have other car seats you love? Let me know in the comments! And to keep up with all the tips for your family car, check out my recent posts: