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How to Bypass a Key Card Lock and Access Hotel Rooms With Ease

Fact checked by Teddy B.Miller

how to bypass a key card lock

Key card locks have become one of the most advanced and efficient security methods to either permit or restrict one’s access to a particular area.

Most hotels choose to equip their doors with key card locks due to the high level of protection, believing that this type of lock will secure guests’ belongings in the room. But the truth is you can hack a key card lock much easier than you can imagine.

In this article, we will explain how a key card functions, along with how to bypass a key card lock with cheap tools. You would definitely be surprised by how simply things are done.

What You Will Need to Follow This Tutorial

The tool required to complete a key card door lock hack is quite easy to get at a low price (cheaper than $50). It is an Arduino microcontroller. Other than that, all you need is a little programming and clear instructions.

Step by Step Instructions


We will demonstrate the process with an Onity key card lock in specific. Here is how even the most amateur lock user can easily hack hotel door locks with a cheap item and simple skills.

The base of every lock of this type contains a DC power socket. This part does the charging work for the device’s internal battery and also programs your lock with site codes of the particular hotel, which is a 32-bit key for identification.

After plugging your programmed microcontroller inside this power socket, you will find the Arduino item reading the 32-bit key and triggering the lock to open. The reason is the lock’s memory location is the same for every Onity lock.

Surprisingly, the whole procedure to read the site code only takes you about 200 milliseconds, from the first act of plugging the microcontroller to when the lock opens.

Although the implementation does not succeed with every single lock, the rate is still 1 out of 4 hotel doors. Nonetheless, with a bit more effort in programming, we believe that this method can work with all possible key card locks.

What Is a Key Card? How Does It Work?

A keycard plays the role of a security token to let you get through doors run by electric power. Such a system will require you to use a key card reader installed on the door, which allows you to gain access by: swiping the card on this unit, inserting it, or tapping it.

Thanks to the invention of keycards, there is no need to enter a traditional key into tumbler locks to open doors anymore. The embedded access credential is engineered on the card magstripe or a chip, and your reader will scan this every time you want to unlock the door.

As soon as the smart reader recognizes your unique card code, it will permit you into the room. Since this unit is wired to your door’s electric lock, it sends a signal to the lock to trigger an opening process.

A good lock system only takes less than one second to finish unlocking. Our tutorial on how to unlock a key card door can help you achieve this quick timing with low-cost tools and simple techniques.


Now that your concern of how to bypass a key card lock has been solved, what is your opinion on the article? If you find it helpful, do not hesitate to spread the word with friends and family via social media so they also know this process better.

Thank you for reading!

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