Both are booster car seats — here are their published manufacturer specs side by side.
This compares published manufacturer specs — not safety or fit advice. The seat's manual, your vehicle's manual, NHTSA's tools and a certified CPST are the fit-and-safety authority; always check them before installing.
Spec
Evenflo Big Kid
Graco Affix Highback
Stage
Booster
Booster
Narrow (3-across)
–
–
Extended rear-facing
–
–
FAA-approved
–
–
Lightweight / travel
✓
–
How they differ
the Evenflo Big Kid is the lighter, more travel-friendly model
Published limits
Mode
Evenflo Big Kid
Graco Affix Highback
Booster (with back)
40–110 lb · 40–57 in · 4+ yrs
30–100 lb · 38–57 in · 4+ yrs
Booster (backless)
40–110 lb · 40–57 in · 4+ yrs
40–100 lb · 40–57 in · 4+ yrs
Useful life
—
10 yrs from manufacture
Evenflo Big Kid: Belt-positioning booster convertible between high-back and backless mode (identical weight/height/age requirements printed for both — manual: Evenflo Big Kid/Big Kid LX Booster Seat). Not a harnessed seat. Useful life is set by the expiration date on the manufacture label (no printed number of years). Note: manufacturer PDF filename/URL says 'us_amp' but the actual document is the Big Kid/Big Kid LX manual (confirmed by title page) — Evenflo's 'Amp' product is a different manual, hosted at a URL confusingly named 'bigkid-backless-booster-car-seat'.
That is the record of the brand — not a verdict on these models. A recall names specific models and manufacture-date ranges, and a seat missing from the record is not "recall-free": check nhtsa.gov/recalls with the model and date of manufacture on your seat's label. Source: NHTSA, retrieved 2026-07-16.
As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Affiliate links never affect our specs or which seats we compare.
FAQ
What's the difference between the Evenflo Big Kid and the Graco Affix Highback? The Evenflo Big Kid is lightweight/travel; the Graco Affix Highback lists none of the narrow / extended-rear-facing / FAA / lightweight flags. Both are booster car seats.
Which is right for my car and child, the Evenflo Big Kid or the Graco Affix Highback? That depends on your specific vehicle and child — this page compares published manufacturer specs only, not fit or safety. Check the seat manual, your vehicle manual, NHTSA's car-seat finder and ideally a certified CPST before deciding.
Citing these specs? Go ahead — published manufacturer data, last verified 2026-06-11. Copy a ready-made reference: