Child car seats: How we test child car seats

Child car seats after crash tests We crash test each seat in two specially designed scenarios multiple times

Which? crash tests child car seats in two, specially designed, crash scenarios. Our crash tests are severe and our experts feel they more accurately reflect what happens in real crashes more than the legal minimum standards.

Our child car seat testing reveals big differences between seats. Some protect babies and children well, but others expose them to the risk of serious injury or even death. The best child car seats will provide protection from both front and side impact crashes – two of the most common types of crash.

Each car seat goes through the same tests in our labs, so you can directly compare their strengths and weaknesses.

Our child car seat reviews answer common questions like:

  • Is it safe?
  • Is it easy to fit?
  • Is the seat comfortable?
  • What else do I need to know?

Trial Which? for £1 today? to find out which child car seats we rated as Best Buys, or log in if you already have member access.

Video guide: How we test child car seats

Our child car seat video shows you the huge difference between a good child car seat and a bad child car seat, and talks you through how to find the safest seat for your baby.

Be warned, the footage is quite harrowing, even though we’re using crash test dummies.


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Crash test dummies in back saet

Two crash test dummies are ready to go to work in a front-impact crash test

Is my car seat unsafe? 

Each car seat tested endures a front crash, equivalent to a head-on collision at around 40mph, and a side crash equivalent to two cars crashing into each other at 30mph, repeated again and again, in all the different ways a car seat can be used.

We can go through as many as 20 samples of the same seat to get the final score for just one.

  • Crash tests Our experts have specially designed the crash tests, making them more demanding that the legal minimum standard requires. They’re derived from Euro NCAP – it carries out crash testing on cars to show how well cars protect occupants in severe accidents – we do a similar thing for car seats and feel this more accurately reflects what could happen in a real crash.
  • Crash test dummies These are wired up to record the crash forces on the most vulnerable parts of the body and accurately indicate the risk of injury a real child could have in a crash.
  • Multi-group seats If a car seat can be used in a number of different ways, and attached by different methods (ISOfix or car’s seat belt) we crash test it in each format

Car seat reviews - find out which car seats performed the best in crash testing

How easy is the seat to fit?

Checking a child car seat is easy to install

Our experts check how easy it is to install a car seat

It’s vital to ensure any car seat is fitted correctly. Any car seat, even a Best Buy, would be unsafe if it’s installed the wrong way.

Ease of use tests are not part of the legal requirements, but we conduct a whole range of tests on each seat.

  • Hands-on assessments Parents get hands on with the car seats to try and install them. This gives our experts an indication of the risks of installing a seat wrongly; what could be forgotten or how the seat could be misused.

  • Fitting in cars Each seat is tried in three different makes and models of cars to see how easy it is to fit. Experts consider both Isofix and seat-belt modes
  • Instructions and warning labels Instructions and warning labels are scrutinsed to see whether there is anything confusing, annoying or misleading
  • Trying out the seats Real children of different ages try out each seat, in all the cars, to help highlight any safely issues or problems using the seat on a day to day basis - something our dummies can't tell us

How to fit a child car seat - our handy videos can help remind you how to fit your seat safely

Crash test dummy in used seat

We check how comfortable your child will be in their seat

The best position for your baby

Our testing includes an ergonomic assessment of each seat to make sure your child will be in the  best position when they travel.

  • Space Experts check how roomy the seat is for your child, and how much space they'll have to grow and the head support
  • Space in the car How much space a car seat takes up is important, too. If it takes up too much there may be none left over to safely transport other children, or even space for the passenger in the front seat 
  • Comfort for the child This covers how much support there is for the child's legs, the padding and their view
  • Position of the child We check to make sure the child will be help in a good position while they travel, which is especially important for babies.

How Which? makes car seats safer - find out how we've spent 50 years making seats safer

Should I buy it? 

We analyse our crash test results, ease of use data and ergonomic assessments to give each car seat a total test score, so you can see which are the best and worse and directly compare models to each other.

The child car seat test score ignores price and is based on:

  • Safety (front crash; side crash; seat design, stability in the car, belt routing) 60%
  • Ease of use (installation, possibility of misuse, instructions, adjusting the set, cleaning and workmanship) 30%
  • Ergonomic assessment (posture, comfort, space for child, support, padding, view) 10%

Group 0 or 0+ Best Buys must score 77% or higher. 

Group 1, 2 or 3 Best Buys (or any combinations of these groups) must score 74% or higher.

Any car seat scoring 40% or less will become a Don't Buy.

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