Under normal circumstances, you’d never want to break a window in your vehicle. For one thing, broken glass is dangerous. For another, it would be costly to replace a broken window. However, there are a few emergency situations that might justify breaking a car window as a last resort.

Why Would I Ever Need to Break My Car Window?

There are a handful of unlikely, extremely rare situations:

  • You’re outside your vehicle and accidentally lock your keys inside along with your child or pet. 
  • You’re in an accident and you must exit the vehicle quickly (for instance, in the event the vehicle is on fire), but you aren’t able to open the door or roll down the window. 
  • You crash or run off the road into a body of water and your car gets submerged, or your car gets submerged in a flood situation. 

Why Are Car Windows Difficult to Break?

Before we get into how to break a car window in each of these situations, let’s look at why car windows are so difficult to break. 

Laminated glass is used for the side windows and some rear windows on many newer vehicle models. This type of glass is actually much more resistant to breakage than tempered glass (which shatters when it breaks). Laminated glass lessens the likelihood that you’ll be ejected from your vehicle in case of a crash. Statistically speaking, laminated glass will do a better job protecting you from injury and even death than tempered glass. 

But when it comes to breaking the glass in the extremely unlikely situations mentioned above, laminated glass could prevent you from doing just that. If you have an emergency spring-loaded punch tool in your vehicle designed to break glass, it won’t work on laminated glass windows. 

What Do I Need to Know About Breaking a Car Window?

If you ever do find yourself in a worst-case scenario that requires you to escape your vehicle by breaking a window, here are the important things you need to know. 

First — as in right after you read this article — do some quick research to learn which windows in your car are tempered glass and which are laminated glass. You can check this list from AAA, as well as check with your vehicle’s manufacturer. If you have a sunroof or moonroof, those are typically tempered glass, as are rear windows (but not always — like we said, check with the manufacturer). 

Second, stow a punch device in your car, so you’re more likely to have it available if you need it.

Situation 1: You’re outside your vehicle and have accidentally locked your keys inside along with your child or pet.

This can be beyond scary, especially here in Arizona, where vehicles can quickly reach deadly temperatures inside. 

If this happens to you — or if you observe a small child or pet trapped inside a parked, locked vehicle that isn’t your own— here are some steps you can take to break a window. (Note that under an Arizona state law passed in 2017, anyone who believes that a child or pet in a hot vehicle is in “imminent danger” of suffering injury or death can break a window to get them out without fearing a lawsuit, but you must contact law enforcement first.)

  1. Call law enforcement and alert them to the situation. If it’s not your vehicle, quickly snap a photo of the situation with your phone, if possible. 
  2. Plan to break a window that is not near the child or animal inside the vehicle. Remember, you’ll need to break a tempered glass window, rather than a laminated glass window, which will resist breakage. 
  3. If you have a tool designed to break car glass, take careful aim at the corners of the window to break it. That will be far more effective than trying to blast through the center of the window.
  4. If you don’t have such a tool, then remove a spark plug from under the hood of your vehicle. 
  5. Smash the spark plug into the ground (concrete or pavement) or the side of a cement block building. You’re trying to break off some of the sharp pieces of the spark plug’s porcelain coating. 
  6. Carefully pick up the shattered porcelain pieces and throw one at the window. The sharp point on the porcelain will focus the force, and should cause a tiny fracture on tempered glass, which will spread out into spider-web looking cracks. 
  7. Remove as much of the crumbled bits of glass as you need to access the internal door handle and open the door. 

Situation 2: You’re inside the vehicle and must find a way to escape, such as in the event the vehicle is on fire or submerged in water. 

This situation is extremely rare. Less than 1% of all crashes result in the vehicle becoming submerged in water, according to AAA. However, it can be helpful to know what to do if you ever need it. 

  1. Stay calm. If you can call 911, do so. 
  2. Unbuckle your seatbelt, and if you still can, get out of the vehicle. 
  3. If you’re not able to open your door, roll down your window and exit the vehicle that way. 
  4. Try to break the tempered glass window with a glass-breaking escape device (sometimes called an emergency window punch) and exit out that window. If your car is submerged, you may need to wait for the car to fill with water before breaking the glass, so the glass doesn’t implode into the vehicle. 
  5. If you’re unable to break the windows, shift to an area of the vehicle that has a pocket of air (that has not yet been flooded by water) and remain there. As the vehicle fills with water, the pressure in the vehicle should equalize, and you may be able to open a door to escape. 

We believe that breaking a vehicle window should always be a last resort, and that it’s important to involve the authorities first whenever possible. Our goal at Stop and Go Driving School is to make sure you can keep others — and yourself — safe on the roads. 

Learn about our driving courses today.