Car seats & travel · Last checked Sep 30, 2026
Britax Poplar S Convertible Car Seat
Verdict
Only 17" wide, so three can fit across most back seats, with ClickTight and an anti-rebound bar.
17" wideRear-facing to 50 lbClickTightFR-free fabric
What parents and testers say
Recurring praise
- Fits three across
- Easy ClickTight install
- Anti-rebound bar
Recurring complaints
- 28 lb
- Belt install recommended
Our summary of patterns across the reviews and threads linked below. Not quotes.
Materials & safety check
✓Flame retardantsFree of added flame-retardant chemicals (per Safe in the Seat's list; confirm the fabric version)
✓RecallsNone for this model in the NHTSA record since 2023
!InstallHave a certified passenger safety tech (CPST) check your install
When to buy it
Registry
Optional now; you'll need it when baby outgrows the infant seat
~9–15 months
Buy and install before the infant seat's height or weight limit
Years 2–4+
Keep rear-facing as long as the seat's limits allow
Consider instead: Graco SlimFit3 LX for a cheaper slim seat.
Sources
- The Bump: Best convertible car seats, tested
- Safe in the Seat: Guide to flame retardants in car seats
- SeatFitFinder: NHTSA car seat recall record
Spot something wrong or out of date? Email [email protected] and we'll recheck it.