You might face the unfortunate situation in which you leave your keys in a locked car. You could get a locksmith to come and unlock your car — or if you’re close enough to home, get a spare set of keys. However, there is another option for some types of cars. Try this secret trick to unlock a car door.

Use shoelaces or strings to unlock a car door 

When you lock your keys in your car, a feeling of panic and frustration is understandable. However, drastic measures might not be necessary. If you have a vehicle with a locking tab mechanism that slides vertically up and down — which is usually by the window, then you’ll likely be able to unlock the door with a shoelace.

First, find a good pair of shoelaces. As done by Captain Lock Pick, you can just take the shoelaces off the shoes that you’re currently wearing. You’ll need both of the shoelaces. Alternatively, you can use some strings. However, the strings must be thick and sturdy, so they don’t break when you try to open the door. 

How to open a car door with shoelaces or strings

After you’ve obtained the shoelaces (or strings), follow these steps to unlock a car door:

• Tie the shoelaces together by making a double knot, tying them together at the end of each lace.
• Around 3/4 of the way down the combined shoelaces, form a loop and tie another double knot. 
• Take the long side of the shoelace to the top corner of the door jam. Then, slide the string behind the door — toward the front of the car. From there, pull it from side to side until you can see the loop from the shoelace inside the cabin. 
• Now comes the most challenging part. Place the loop over the locking mechanism. This might require multiple attempts.
• After you successfully hook the loop around the locking mechanism, pull the shoelace tight toward the back of the car. Use the short end of the string to pull.
• Slowly lift up the shoelace until you unlock the car door. Also, be sure to use steady pressure, for a loose string can easily slip off the lock. If you don’t succeed on the first attempt, then keep trying. 

Other points of consideration

It goes without saying, but you should only use the shoelace/string unlocking method for a car that is your own — or as approved by a friend or relative. Don’t use this newfound knowledge to steal a vehicle. One of the commentators for the Captain Lock Pick YouTube video stated (likely joking), “Thanks, comrade, now I have a new car.”

Also, this method only works for a locking mechanism that slides vertically. It won’t work for a horizontally-sliding mechanism.

If you’re unable to open your car door, then get assistance from an automotive association, such as AAA, or a car service center, who can send a local locksmith. Alternatively, you can call the non-emergency number for the police or dial 4-1-1 to get the phone number of a local locksmith.

There’s another unusual car door unlocking method that has long been making the rounds on the internet: a tennis ball. To find out if the tennis ball method really works, continue reading below.