Search  for anything...
Britax

Britax One4Life Slim All-in-One Car Seat, 10 Years of Use, 17.5” SpaceSaver Design, Converts from Rear-Facing Infant Car Seat to Forward-Facing Booster Seat, ClickTight Installation, Sea Foam

  • Based on 1,118 reviews
Condition: New
Checking for the best price...
$429.99 Why this price?

Buy Now, Pay Later

As low as / mo
  • – Up to 36-month term if approved
  • – No impact on credit
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, PayTomorrow, Affirm, Afterpay, Apple Pay, and PayPal. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

This item is eligible for return within 30 days of receipt

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

Availability: In Stock.
Fulfilled by Amazon
Arrives Wednesday, Aug 27
Order within 3 hours and 43 minutes
Available payment plans shown during checkout

Recently Viewed

Color: Sea Foam


Style: One4Life Slim


Features

  • All-in-One Car Seat: One4Life(R) Slim is a convertible and harness-2-booster seat in one! It easily converts from a rear-facing infant and toddler seat (5-50 lbs.) to a forward-facing seat (30-65 lbs.) to a high-back booster seat (40-120 lbs.)
  • ClickTight(R) Installation: Install with confidence in 3 easy steps: pinch to open, thread and buckle, click it closed!
  • SpaceSaver(TM) Design: Slim outside, spacious inside! The 17.5 seat is designed to fit 3 across without compromising on trusted Britax safety and premium comfort *Britax cannot guarantee 3-across installation fitment in all vehicles
  • Premium Car Seat Cover: Features a soft knit fabric with woven melange accents that are made from recycled polyester; the cover is safe to machine-wash and dry and naturally flame retardant with no added FR chemicals
  • Trusted Britax Safety: Features a patented V-shaped tether, SafeCell(R) technology, a high-strength steel frame, and two layers of energy management
  • Comfortable Rides: This slim car seat includes soft comfort pads, built-in mesh cooling channels, three infant inserts, plush padding, and a tag-free headrest
  • Easy to Adjust: The 15-position no-rethread harness and headrest adjust together easily with one hand, and the 9-position recline has an easy-read indicator to help you find the correct angle for your vehicle
  • Slide-Out Cup Holders: The dishwasher-safe cup holders slide out with ease for convenient cleaning and click back into place for a secure attachment during rides
  • Accessible Color-Coded Belt Paths: Make it easy to route the seat belt through the correct path for each car seat mode
  • Hassle-Free Cleanup: Extra space between the shell and base means you can clean under the seat with ease and with minimal grooves in the seating area and base, you can wipe it down with no fuss

Description

The One4Life(R) Slim all-in-one car seat takes your child from birth to big kid with trusted Britax safety, ClickTight(R) installation, and a slim SpaceSaver(TM) design. As a convertible and harness-2-booster seat in one, it grows with your child for 10 years. It starts rear-facing with an extended capacity of up to 50 lbs., so your child can ride rear-facing longer. It easily converts to forward-facing toddler mode (up to 65 lbs.) and high-back belt-positioning booster mode (up to 120 lbs.) when your child is ready. With a slim outside and spacious inside, the 17.5” seat is designed to fit 3 across without compromising safety and comfort. ClickTight helps you install with confidence, every time. The base and shell are easy to wipe down for hassle-free cleanup. The car seat cover is safe to machine wash and dry, and it’s naturally flame-retardant with no added FR chemicals. One4Life Slim features a high-strength steel frame, a SafeCell(R) crumple zone, and a V-shaped tether. As your child grows, you can easily adjust the 15-position no-rethread harness and headrest with one hand. With cooling channels, premium padding, three infant inserts, and built-in armrests, your child will love every ride. Britax cannot guarantee 3-across fitment in all vehicles.

Brand: Britax


Installation Type: Seat Belt


Material: Alloy Steel, Plastic


Color: Sea Foam


Orientation: Rear and Forward Facing


Product Dimensions: ‎18.5 x 17.5 x 24.5 inches


Item model number: ‎E1D437F


Minimum weight recommendation: ‎5 Pounds


Maximum weight recommendation: ‎120 Pounds


Minimum height recommendation: ‎18 Inches


Maximum height recommendation: ‎49 Inches


Material Type: ‎Alloy Steel, Plastic


Material Composition: ‎Plastic and Steel


Care instructions: ‎Machine wash and dry cover


Style: ‎One4Life Slim


Number of reclining positions: ‎15


Batteries required: ‎No


Orientation: ‎Rear and Forward Facing


Rear-facing maximum child weight: ‎50 Pounds


Forward-facing minimum child weight: ‎30 Pounds


Forward-facing maximum child weight: ‎120 Pounds


Harness type: ‎5-Point


Item Weight: ‎28 pounds


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Aug 27

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Favorite seat! Read for fit tips
Color: Glacier Graphite Style: One4Life
Review Image by RaeMars23 RaeMars23
My car seat hater enjoys the car much more in this than his infant seat. My 3 year old has one too and we love how comfortable they are, the less strict accident policy (had to replace a Graco extend 2 fit twice in 6 months bc of their replace in any and all accidents policy), that you can machine wash the cover with light detergent and how easy they are to install. Very high quality car seat that's very easy to adjust! CARSEATS WILL NOT PROTECT YOUR CHILD IF USED INCORRECTLY: -Top of chest clip should be level with armpits -Straps should come from below the shoulders rear facing and above the shoulders for forward facing -Slack should be removed from the hips, then tighten just enough so you're unable to pinch the straps at the shoulder vertically -DO NOT add any inserts, strap covers or head positioners that didn't come with your seat, they are not crash tested for your seat and will void the warranty in the case of an accident -Nothing should be attached to the seat or its straps (like binky clips, toys etc) -Wash per your manual -Rear face until absolute minimum of 2, it's their bone development that matters most -If you go see someone to help you install your seat make sure they are CPST (Child Passenger Safety Technician) -READ YOUR MANUAL) The group Car seat Safety on Facebook is extremely helpful ... show more
Reviewed in the United States on July 16, 2025 by RaeMars23 RaeMars23
    • Love Britax!
Color: Parchment Style: One4Life Slim
This car seat is incredible. After moving up from an infant car seat, we started with the rotating Chicco car seats and the rotating feature was the only thing I liked. It never felt fully secure, and at just 14 months my LO’s legs were already scrunched up. The steal frame seat on the Britax makes me feel so confident in my baby’s safety. The installation is so quick you’d think you did it wrong if it wasn’t for how secure it felt. The padding is so plush and comfortable. It’s ridiculously easy to adjust as your baby grows and it automatically adjusts the straps as well as the back of the seat at the click of a button. So easy to tighten and loosen to get LO in and out. I also appreciate the removable cup holders to ensure you truly can fit multiple car seats across your back seat bench. Lastly, and yes least important, the color is gorgeous. Truly the only thing that could make it better is a rotating feature but from my obsessive research, they seem to notably feel less secure. I’d rather my babe be safe at the slight inconvenience for me getting him in. I’d say the value for price is incredible. ... show more
Reviewed in the United States on July 1, 2025 by MC
    • The only car seat brand we will ever buy for our kiddos! Only cons are the weight and width.
Color: Eclipse Black Style: One4Life
I have recommended this car seat to sooo many of my friends! If you have ever used the Click Tight system you know exactly why! This is the absolute easiest car seat to install/remove and you get the tightest installation EVER! I really love that the car seat is so sturdy and well built! There are so many safety features built in too! We upgraded to the One4Life with our last kiddo from the Advocate. One of the best features that I didn’t know I needed was the cup holders! I love that Britax added them onto this car seat! This car seat has so many pros! There are a few cons however in our opinion. The car seat is VERY heavy (which is great for safety but heavy to move). The other con is that it is very wide (again this is great for safety but we are not able to go 3 car seats wide in the backseat because of this). Even with these 2 cons we will never use another brand of car seat! ... show more
Reviewed in the United States on July 17, 2025 by Noël
    • Highly recommend
Color: Jade Onyx Style: One4Life
Review Image by artzone artzone
I just purchased this car seat. First off How it looks: beautiful love the style comes in many colors and styles i did the one 4 life click tight ( it is actually true it installs tightly). Supper soft and easy to follow instructions. What features: well I purchase this for easy installation and it also looked very comfortable too when it arrived it had many cushions and air netting on the sides for to breath. Side button with one push and easy to adjust tilit It was easy to find the buttons all labeled side and under the seat. Pros: easy to read and understand, easy to adjust and installation was a breeze. Once installed correctly it dosent move at all very impressive as I have had many car seats and they always move a little even once installed correctly this one was zero movement highly recommend for safty. Con well I don't really have any yet it is so far everything I hoped for. So weight: well it is on the more heavier side but it's not any heavier than Carring a baby carrier with base. It is solid to carry and solid once buckled. Other qualities it also is approved for other transport such as a plan if you wish to fly. What I love is the tilt feature and how it grows with your child, easy to install and read direction on the car seat visible and it is in two languages. The cushions for the head is very comfortable. Highly recommend for baby on up however I already pass the baby stage carrier and purchase this after my child was already one. It can even use for infants up to 10 years old Again highly recommend ... show more
Reviewed in the United States on February 21, 2025 by artzone artzone

Can't find a product?

Find it on Amazon first, then paste the link below.
Checking for best price...