Skip to content

SeatCheck

Live

What child car seat does the law actually require, in every US state

Built by · Launched June 2026

Try it live
SeatCheck share card: a teal shield with a check mark above the SeatCheck wordmark in a bold serif, the line "Car seat laws for every state, in plain language," and a "Verified from official state statutes" pill.
web astrocloudflare-pagesymyldata-sourcingembeddable-widget

What is SeatCheck?

SeatCheck answers one question, for every US state, with a citation: what child car seat, booster, or restraint does the law require? It exists because the honest answer is genuinely hard to find. The rules change at every state line, the official statutes are often buried or locked behind clunky portals, and most of what ranks online is ad-choked guesswork that blurs “the law” with “what a pediatrician recommends.”

It covers 56 jurisdictions: 50 states, DC, and five territories. For each one it shows the legal requirement and, separately, the American Academy of Pediatrics best-practice recommendation, so the two are never mistaken for each other.

How it works

You pick a state and enter your child’s age, height, and weight. SeatCheck returns the restraint the law requires there, rear-facing car seat, car seat or booster, or seat belt, and cites the exact statute. The same checker is published as an embeddable widget any site can iframe in.

Key Features

  • All 56 US jurisdictions, each statute-sourced with its own last-verified date and source tier
  • 84 state-vs-state comparison pages generated by a deterministic engine, so two pages differ exactly as much as the underlying law differs
  • Law and recommendation kept separate, with the legal requirement as the floor and AAP guidance shown as best practice, never as a requirement
  • Embeddable widget: no cookies, no accounts, self-contained CSS and JS, themeable by the host site and deep-linkable by URL parameters
  • Provenance tooling: three lint scripts catch unsourced facts, internal contradictions, and dead source links so the data does not silently rot

Why it is built this way

SeatCheck is YMYL (you-your-money-or-your-life) child-safety content, which is why accuracy and provenance are prioritized over speed. Every threshold traces to the official statute, a statute that is silent on a value is recorded as null rather than filled with a reasonable guess, and the AAP recommendation is stored and displayed as a separate field so it can never be presented as law. A wrong car seat age is not a cosmetic bug, so the whole system is built to make a wrong number hard to ship.

Visit SeatCheck

Frequently asked questions

What does SeatCheck tell a parent?
You pick a state and enter your child's age, height, and weight, and it returns the restraint the law requires there: a rear-facing car seat, a car seat or booster, or a seat belt, with the exact statute cited. Alongside the legal answer it shows the AAP best-practice recommendation, which is usually stricter, clearly labeled as guidance rather than a legal requirement.
Which states does it cover, and how accurate is the data?
All 56 US jurisdictions: 50 states, DC, and five territories. Every fact, ages, heights, fines, and citations, traces to the official statute and carries its own source URL, last-verified date, and source tier. Three lint scripts continuously check that nothing is unsourced, internally contradictory, or pointing at a dead link, and the data is refreshed against the official sources rather than secondary summaries.
Can I add the car seat checker to my own site?
Yes. Besides the standalone site, SeatCheck ships an embeddable widget that parenting, gear-review, and family-travel sites can drop in via an iframe. It carries its own styling, sets no cookies, needs no accounts, detects the host theme, and resizes itself. You can pre-fill a state and accent color with URL parameters.
Is SeatCheck legal advice?
No. It is a plain-language summary of the statutory requirement with the official citation so you can read the law yourself, plus the separate AAP best-practice guidance. It does not replace reading the statute or talking to a certified car seat technician.

Related projects