How To: Make a Homemade Lie Detector Test

Did your girlfriend throw away your favorite concert t-shirt from college? Did your boyfriend really go visit a sick friend last Saturday night at 11pm? It’s time to get the answers to these questions and more with this homemade lie detector test.

Richard wrote a post here on Bit Rebels called “How To Detect a Lie.” It is one of the most popular posts ever written on this site, so as a follow up, I thought I’d take it one step further and show you how to make one of these nifty little homemade lie detectors for yourself.

Let me warn you, in order to make this, you will need some knowledge of electronics. However, the schematics are relatively simple. How accurate is this? According to, a lie detector test does not actually detect a lie; instead, it “measures the skin resistance which goes down when the subject is lying.” So, I wouldn’t hold anyone to the results you get from this homemade version, however, I can think of a lot of ways to have fun with this for sure!

If you think you’ve caught someone in a lie, try doing what the police investigators do: Give them the silent treatment. Silence will make your lying friend feel uncomfortable and he or she will probably just start babbling and you never know, he might just tell on himself or get his details confused.

Good luck!

How To Make a Homemade Lie Detector on Howcast