A long-held claim on the internet is that you can unlock your car door with a tennis ball. While it’s unknown who first made this claim, this supposed “car hack” started spreading on the internet in 2007 — including with a grainy YouTube video demonstrating the claim. In 2016, this hack gained even more attention with many users posting videos and descriptions on social media sites and blogs. Is this claim really true? Can you unlock a car door with a tennis ball?

How the ‘unlocking a car door with a tennis ball’ hack works

The descriptions across the internet of the “unlocking a car door with a tennis ball” hack are fairly similar. They generally start by discussing the frustration of locking your keys in a car. Then, they describe your limited options for dealing with the problem. This includes getting a ride home to get your other set of keys, calling a tow service to unlock your car, and doing the usually ineffective coat hanger method. 

The descriptions then suggest an alternative: the tennis ball method. Take a tennis ball, and puncture a small hole in it. After that, place the tennis ball over the keyhole of your car with the hole section covering it. Then, using both of your hands, press the tennis ball very hard against the keyhole. By doing this, you force air into the locking mechanism — and the car door gets unlocked. 

Here’s the 2007 video with the tennis ball claim. The music in the video is very loud, so you might want to turn down the volume before watching it.

False: You can’t really unlock a car door with a tennis ball

If the tennis ball car door unlocking method sounds too good to be true, then you’re justified in your sentiments. This claim is false. You can’t really unlock a car door with a tennis ball.

For one, if unlocking a car door was this simple, it would be easy for any car thief to steal a car, as detailed by Snopes. All they would have to do is invest in a collection of tennis balls. While car theft is still a problem, there hasn’t been a dramatic increase since the 2007 video. 

Furthermore, the tennis ball car door unlocking rumor caught the attention of MythBusters in 2007. The hosts of the Discovery Channel program debunked the myth in a web video. First, the MythBusters team attempted to replicate the results of the “air pressure” tennis ball hack that had proliferated on the internet. Unsurprisingly, this attempt failed. 

Additionally, the team tried to unlock a car door with much higher air pressure. They attempted this by vacuum-sealing the car lock — and then applying 100 psi of air pressure. However, this method also failed. They busted the myth. 

Garage parking and other ‘real’ auto-related tennis ball hacks

While the tennis ball car door unlocking claim is untrue, there are “real” ways that you can use a tennis ball for your car. This includes using a tennis ball to mark the spot in which you need to park in your garage. To do this, hang a tennis ball from the ceiling in your garage, with the ball extending down to the height of the windshield. When you drive into your garage, stop your car at the point at which the windshield touches the tennis ball.

Another good use for a tennis ball is during long road trips. As your body becomes stiff from sitting in a vehicle for a long time, you can use a tennis ball to massage your tense muscles. 

Another common car-related use for a tennis ball is on an antenna, particularly for older cars with a long antenna that can easily sway. Placing a tennis ball on an antenna can prevent it from swaying and potentially knocking into a vehicle. However, by doing this, the effectiveness of the antenna might be reduced.

For another “real” car-related hack, check out the article below about the “apple on a windshield trick.”