The 3 Best Car Window Breakers, Tested on Real Car Windows

Basic window-breaker hammers often come in roadside-emergency kits or even as a freebie from your car dealership. They’re cheap, and they have no moving parts that can break or jam, but they have one serious flaw: They require you to swing them hard enough to break the glass.

In an accident where you could be injured or pinned in an awkward position, that swing room isn’t guaranteed, so in finding models to consider for this guide, I eliminated manual glass breakers from contention. (The exception is the Lifeline Evac-Pro, because a spring-loaded punch can’t generate enough force to make a hole in laminated glass.)

For the same reason, I also eliminated any tool that required two hands to operate.

Instead, I focused on tools that could produce a spring-loaded punch triggered by a minimal amount of force that could be deployed with one hand.

Many of them had a similar handheld, keychain-size form, and those tools were worth testing for their portability and ease of use. I also looked for long-handled versions that would protect your hand a bit more and put more room between glass and skin.

Ultimately, I settled on testing one classic hammer as a control, five spring-loaded window breakers, one wallet-sized uniquely designed entrant, and one laminated-glass cutting saw.

Because there’s no good proxy for breaking a car window, I sought out some car windows to break.

I connected with Paul DeBartolomeo, a career firefighter and the owner of Connecticut Custom Fire Training, where he teaches courses on vehicle extrication to first responders. On a blisteringly hot summer day, we set up at the Stamford Fire Department drill field and tested glass breakers on tempered-glass windows. I also tried a few of the tools on the cars’ laminated-glass windshields to prove their insufficiency on that tougher, shatterproof glass.

As we tested, a handful of on-call firefighters wandered out of the firehouse to observe what we were up to. They shared their vehicle-extrication tips and tricks with me and demonstrated their go-to professional tool for extricating crash victims from vehicles with laminated-glass windows: a mean-looking saw called the Glas-Master.

The operator took a few strong whacks at the windshield with the butt end of the tool to create a purchase hole for the blade. He then cut through the windshield with the specialized saw, which cuts on the pull stroke. Reassuringly, getting in took him about 20 seconds.

I left Stamford pretty confident in my tempered-glass breaker contenders, but I was still at a loss for what to recommend for laminated glass, aside from calling 911 as quickly as possible.

It was then that I stumbled upon the Lifeline tool — pretty much the only consumer-facing tool for cutting laminated glass — on a Cybertruck owner forum.

Your other options are limited to the Glas-Master (huge, unwieldy, and likely difficult to use from inside a car) or a specialized glass-cutting drill bit called the Beluga. (Again, it’s probably not practical to keep a charged-up drill in your glove box just for emergencies.)

I connected with Lifeline’s team, and they agreed to source a couple more car doors for me, specifically with laminated-glass windows. This time, I found myself in northern New Jersey, at another drill field, having the tool demoed for me and cutting through some laminated glass myself.

I then took my top contenders and tested them repeatedly on small rounds of tempered glass. I deployed each tool five times in quick succession to confirm that they wouldn’t jam with repeated use.

Really, you need the tool to work only once — but on that one time, it had better work.