Nuna · High-back booster

Nuna aace

Based on 3 independent scored tests: BabyGearLab (2026), Insurance Institute for Highway Safety (IIHS) (2017), NHTSA (National Highway Traffic Safety Administration) Car Seat Ease of Use Ratings (2021). The test scores average 85. With only 3 tests, the ranking score is pulled down a little until more testers confirm it.

Tested for US & Canada
78
Shortlist score
Good
#36 of car seats for US & Canada
High confidence

Where to buy

This seat is certified for US & Canada. Car seats may only be used in the market they're approved for, so we don't link to shops in Czechia.

Test results

Each score as the tester published it, converted to our 0–100 scale. Weight is how much the result counts towards the score.

BabyGearLab US · Editorial review
BabyGearLab best booster seat review, 2026
83%
Best Overall Booster Car Seat
Our scale83
weight 0.60
Crash test
9.0
Ease of use
8.3
Weight size
6.9
Comfort
8.0
Quality
8.0
Listed at $300 metric weights: Crash Test (35%); Ease of Use (25%); Weight/Size (15%); Comfort (15%); Quality (10%); overall listed on https://www.babygearlab.com/topics/vehicle-safety/best-booster-seat/ratings; review last modified 2026-08-07
NHTSA Car Seat Ease of Use Ratings, 2021 · booster mode
4/5★
4 stars
Our scale80
weight 0.24
Labels
4
Instructions
4
Securing child
2
Vehicle installation features
5
NHTSA Ease of Use rating for Booster mode (Highback/No Back); seat type Booster; model #CS07007GRN; evaluated seat manufactured 2021-12-07; test_year = year of manufacture of the evaluated seat (NHTSA does not publish a rating date in the data)
Wirecutter (The New York Times) US · Editorial review
Wirecutter: The Best Booster Car Seats (updated Jun 26, 2026)
Other high-back booster seats worth considering
Pick or pass/fail. Shown, not scored.
read on archived copy (web.archive.org, 20260827) of https://www.nytimes.com/wirecutter/reviews/best-booster-car-seats/ (live site blocks automated fetch)
Car Seats for the Littles US · Editorial review
Car Seats for the Littles: Recommended Seats USA, 2025
Recommended
Pick or pass/fail. Shown, not scored.
CSFTL recommended-seats list (CPST editorial picks); section last modified July 7, 2025
3 older or duplicate results not counted
IIHS booster ratings: new booster models for 2017 (released Nov 21, 2017) · highback mode
Best Bet
Our scale90
not counted

Not counted: Another configuration scored higher in the same test.

listed as a new model in the IIHS release for this rating year; rating covers booster-mode belt fit only
IIHS booster belt-fit ratings (final ratings list, program 2008-2024) · backless mode
BEST BET
Best Bet
Our scale90
not counted

Not counted: Superseded by a newer test from the same source.

Tested model #CS-40-003; seat type: Dual mode, Backless; rating year not shown on the IIHS ratings list; rating covers booster-mode belt fit only (IIHS does not rate harness modes)
IIHS booster belt-fit ratings (final ratings list, program 2008-2024) · highback mode
BEST BET
Best Bet
Our scale90
not counted

Not counted: Another configuration scored higher in the same test.

Tested model #CS-40-003; seat type: Dual mode, Highback; rating year not shown on the IIHS ratings list; rating covers booster-mode belt fit only (IIHS does not rate harness modes)

Also recommended: Wirecutter (The New York Times): Other high-back booster seats worth considering, Car Seats for the Littles: Recommended.

Top-ranked alternatives

How we turn these into one number: methodology. Tested 2017–2026.

KidShortlist

We don't test products ourselves. Every score here comes from an independent tester and links back to it. We combine 4,061 results from 26 sources.

Read before buying

Several testers are paywalled, so we only include what they publish openly. Models change and get recalled. Check the tester's own page and the retailer listing before you buy.

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