Chicco
Chicco KeyFit 35 Infant Car Seat
$249.99Cheaper
Released 2020
Best Car Seats · head-to-head
Chicco KeyFit 35 Infant Car Seat vs CYBEX Sirona S with SensorSafe Convertible Car Seat
A sourced, side-by-side comparison. Chicco KeyFit 35 Infant Car Seat is cheaper at $249.99. Every spec and price links to its source.
Which is better: the Chicco KeyFit 35 Infant Car Seat or CYBEX Sirona S with SensorSafe Convertible Car Seat?
The Chicco KeyFit 35 Infant Car Seat wins 1 of the 1 specs we compare head to head; the other wins 0. The Chicco KeyFit 35 Infant Car Seat is the cheaper at $249.99. The Chicco KeyFit 35 Infant Car Seat both leads on specs and costs less — the straightforward pick.
See Chicco KeyFit 35 Infant Car Seat on Amazon See CYBEX Sirona S with SensorSafe Convertible Car Seat on Amazon
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Chicco KeyFit 35 Infant Car Seat |  CYBEX Sirona S with SensorSafe Convertible Car Seat |
|---|---|---|
| US price | $249.99 | $349.99 |
| Brand | Chicco | CYBEX |
| Released | 2020 | — |
| Type | infant | convertible |
| Min weight (lb) | 4 | 4 |
| Max weight (lb) | 35 | 65 |
| Height limit (in) | 32 in | 49 in |
| Install | both | both |
| Steel frame | Yes | — |
| Expiration years | 6 | 10 |
| Release | 2020 | — |
Sources — Chicco KeyFit 35 Infant Car Seat: chiccousa.com (verified 2026-06-19). CYBEX Sirona S with SensorSafe Convertible Car Seat: cybex-online.com (verified 2026-06-19).
What's the difference between the Chicco KeyFit 35 Infant Car Seat and CYBEX Sirona S with SensorSafe Convertible Car Seat?
Where the two actually differ on the specs we track (4 of 7). Matching specs are omitted.
- Type: Chicco KeyFit 35 Infant Car Seat infant vs CYBEX Sirona S with SensorSafe Convertible Car Seat convertible
- Max weight (lb): Chicco KeyFit 35 Infant Car Seat 35 vs CYBEX Sirona S with SensorSafe Convertible Car Seat 65
- Height limit (in): Chicco KeyFit 35 Infant Car Seat 32 in vs CYBEX Sirona S with SensorSafe Convertible Car Seat 49 in
- Expiration years: Chicco KeyFit 35 Infant Car Seat 6 vs CYBEX Sirona S with SensorSafe Convertible Car Seat 10
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Chicco KeyFit 35 Infant Car Seat
One whitelisted hands-on tester (Reviewed/USA Today) reviewed this exact model, recommending the KeyFit 35 as an easy-to-install, comfortable, washable, budget-friendly infant seat while flagging it as bulky/awkward to carry and unattractive. No lab-measured data exists: Reviewed explicitly states it does not crash-test and relies on NHTSA safety ratings. (1 sourced review, 1 lab-tested.)
Praised: Easiest install of any seat tested; strap-based system clips into LATCH in under 5 minutes with a built-in level; Premium cushioning far superior to other seats tested; cozy headrest and soft fabric kept the baby comfortable; Easy to clean thanks to velcro-detachable machine-washable padding and mess-repelling fabric.
Flagged: Bulky and awkward to carry despite only modest weight; Unattractive orange/gray/black color scheme.
CYBEX Sirona S with SensorSafe Convertible Car Seat
No sourced tester review yet.