Non-Contact Voltage Testers Comparison Review (Fluke, Ideal, Craftsman, Kaiweets)

I suspect most people on Applefritter have used a non-contact voltage tester. They're the sort of thing my mom likes to put in Christmas stockings, so I've ended up with several. There's a lot more differences between them than I would have expected, hence this review.

The Kaiweets testers were provided by Kaiweets, at my request. I think the Fluke, Ideal, and Craftsman were all Christmas gifts from my parents. The prices on all of these are close enough that I don't think price is worth taking into account.

Fluke, Ideal, and Craftsman

I'm going to compare the Fluke VoltAlert, Ideal VoltAware, and Craftsman first, since they're standard testers, while the Kaiweets units try to offer extra features.

Ergonomically, the Ideal VoltAware is the best. All three grip nicely in your palm, but only the Ideal is comfortable when held like a pencil. The Ideal is turned on with a simple, easy twist.   The Craftsman has no power switch and no indicator that it's functioning when it's not alerting.

To turn on the Fluke, you're supposed to short press the recessed power button. If you long press it, it turns on with sound disabled. When you short press the button, there's a pause about the length of a long press, then the light blinks. This, and the unreliable, spongy power button with no tactile feedback, had me thinking you were supposed to long press the button to turn it on. Whether or not sound worked depended on how quickly I let go of the button after the light blinked. I had to look this up in the manual.

The Fluke continues to blink while it's on, to indicate that it's functioning. The problem with this is that it blinks the same color to indicate function as it does for detecting voltage. You can't move it around quickly like you can the Ideal, because you have to hover at every location long enough to see it to blink off, before you know it hasn't detected anything.

The Ideal has a green light to show that it's on and a red light to show voltage detection.

Batteries are easy to change in the Ideal—just twist and pull to open. The Fluke and Craftsman are opened by depressing little clips. It's hard to do without hurting your fingers. You rarely need to change the batteries, but it still shouldn't be painful.

The Craftsman detects current all over the place: in my tool chest, in my fingers if my opposing wrist is resting on my MacBook, sporadically on my metal drawer…  It's fun to play with, but hard to identify a specific wire if there's others nearby.

The Ideal is great. In fact, the Ideal being so much better than the Fluke is what prompted me to write this review. I wasn't expecting such a dramatic difference between two leading brands on such a simple product.

Comparing Kaiweets

The VT500 didn't work for me. I got it to beep a few times right after turning it on (which is far more dangerous than not beeping at all), but not with any consistency. I decided not to ask Kaiweets about a replacement, because even working, it wasn't going to be able to overcome its other shortcomings. Most significantly, it has a metal probe so that it can also do contact voltage testing. I do not want a contactless voltage tester that could suddenly become a contacting voltage tester.

The VT500 has a buzzer, but no light besides the LCD screen. The screen is only on one side and you can't always position the tool so that it's visible. This is particularly frustrating when you're using it to test an outlet, which is almost never going to be oriented properly for you to see the screen.

Kaiweets says the VT500 can also be used as a screwdriver. I opened it up to see how bad of an idea that is. The probe^W screwdriver's connection to the PCB is a solderless friction fit, so you're not going to damage the PCB. What'll happen is you'll break that little piece of black plastic holding the tip in place.

I think the VT500 would be most useful for electrical roulette: Use the built-in screwdriver to remove an outlet wall plate, then close your eyes and see if you can get a contactless reading with the metal tip.

Kaiweet's ST100 made a better impression. It has a traditional plastic tip, and in addition to being a contactless voltage tester, also contains a multimeter. It's much larger than the others, but is surprisingly light. The casing feel very thin, though, like it would be easy to break. It includes a pair of leads, for the multimeter function.

I checked it against a calibrated DMMCheck Plus reference source:

4.999V AC5.010.2%
100.062 kohm99.70.4%
10.000361 kohm9.960.4%
1.0001 kohm.9950.5%
100.065 ohm 99.80.3%
100.003618 Hz99.6 0.4%
10.000361 khz9.970.3%
9.88nf 9.79 0.9%
1.031nf 1.0131.8%

1% accuracy (for everything but capacitance) is sufficient for most uses and quite good for a pocket-sized $20 voltmeter.

Continuity testing works, but is very slow.

My favorite feature of the ST100 is that it has a six-bar LED to indicate voltage level or how close you are to the power source. If you rotate it around a cylindrical power cable, you can figure out which side the hot wire is on. It's a fun feature, but I haven't figure out when it would be useful. Please post in the comments if you have any ideas.

I think the use case for the ST100 is you rarely need a contactless voltage tester and you want a neat toy to keep in your backpack or car.

Testing in an outlet

All of the testers work when laid against a wire, but–amazingly–only the Ideal VoltAware and Kaiweets fit all the outlets and power strips in my house. The tips on the Fluke and Craftsman are too thick for about half of them.


As a contactless voltage tester, the Ideal VoltAware is by far my top pick. As I finish editing this article, I see that it's listed as discontinued on Ideal's website. I hope it will be replaced with something similar. At this writing, the current version is still in stock at Amazon, Lowes, and many other stores.

If you're a hobbyist, and want a neat little portable voltage tester, the Kaiweets ST100 could be a fun device.

Of the five devices compared here, the Ideal VoltAware and the Kaiweets ST100 are the only ones I would consider purchasing.

Ideal Voltaware (Amazon)

Kaiweets ST100 (Amazon)

Kaiweets offered us a 15% coupon and a 15% commission, which I declined. You can find many such coupons by searching youtube for kaiweets 15%.


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Great test, I have that Fluke and I thought is was broken. I should have read the manual, thanks for clearing that up haha. Bad design indeed.