YOJOCKUSB Tester Multimeter Digital 4-30V 0-6.5A, QC 3.0 Power Meter Voltage and Current Tester Detector, Volmeter Ammeter Power Bank Capacity Tester with IPS Color Display

This works great and it's pretty accurate when it comes to current draw. It's a nice quick check to see what USB devices are drawing. Also checks to see that USB power sources are at the correct voltage level and don't drop excessively when something is connected to it. It's great because you put it in line and anything you plug in it immediately shows you real time voltage and current. You can also freeze it and save it.

I just wanted a usb tester to check how much some devices draw when charging, and this little donk fits the bill nicely. Pretty clean and easy to read display, seems accurate, and, well, it works! What more can you ask for? Nice case to protect the display is also included, so it's convenient to toss in with my cables, etc. so I always have it available. Happy.

I purchased the YoJock USB Tester Multimeter to monitor my USB devices, and it worked as expected in terms of showing voltage and current. The digital display was clear, and the build quality seemed decent for the price. However, I ended up returning it because it didn’t offer the full range of features I needed for my projects. It’s a good option for basic testing but may not be suitable for more advanced needs. Overall, a solid product if you’re looking for something simple, but I needed something more specialized.

Had trouble with my PC's USB ports. This was a quick way to determine the voltage under load. It really helped with the troubleshooting process.

This little device is so cool. It allows you to finally see how much current your charger is putting out. But the fun doesn't stop there. It also allows you get an idea of how much capacity the battery actually has.My only complaint is that the display is too small and doesn't present itself as easy to see in my charger. There is really no explanation of the what the button does but I learned that if you push the button twice quickly it changes to the alternate display and 9 slot memory function. quickly pressing the button twice again goes back to the generic display. If you hold down the button it clears out saved data.

Pros: gives a reading of voltage produced by your power brick, power adapter or whatever usb power port you are using so you can assess if it is “safe” to plug in your device. It also gives you a reading of amperage, which tells you how much current your device is drawing (and get to know, for example, if your device is fast-charging). It is also handy if you want it for a more “professional” usage and see if a device is at least drawing power.Cons: it has a USB-A plug and no adapter for USB-C, so, if you need it for testing a USB-C port, you will need to find a USB-A to USB-C adapter.Overall, great little device which gives you important information that can actually save you from plugging your phone, tablet or laptop to an unsafe usb port. (Beware, unsafe electrically, this device does nothing in terms of information security, it’s not meant for that).

Needs to come with a "complementary" magnifying glass! :D

Works and functions.I use it to charge my small devices to see the health of the battery;to see how much a USB is out putting from different chargers.