# Understanding Your Device's Charging Speed: A Parent's Guide to USB-C Cables
Your child's tablet won't charge past 50 percent. Your teenager's laptop takes forever to power up. Before you buy a replacement cable, you need to know what's actually happening.
A free Mac app called USB Prober reveals exactly what your cables are doing. The tool shows you real-time data about power delivery, voltage, and amperage flowing through each connection. Parents often assume a slow charge means a broken cable. USB Prober proves whether that's true.
Here's why this matters. Different USB-C cables deliver different amounts of power. A cable rated for 5 watts charges slowly. One rated for 100 watts charges fast. Your device negotiates with the cable and charger to find the highest safe speed. USB Prober shows this negotiation happening in real time.
Many households have junk drawer cables nobody remembers buying. These older cables often work physically but deliver minimal power. They'll charge a device eventually, but it takes hours. USB Prober identifies these weak cables instantly.
The app costs nothing and requires only a Mac computer. Download it, plug in your cable, and watch the power data appear. You'll see your cable's actual capabilities instead of guessing.
This free tool prevents wasted money. Before spending $30 on a new cable, run USB Prober. You might discover your current cable works fine and something else causes the slow charging. Or you'll confirm the cable truly is the problem.
For families managing multiple devices, USB Prober answers questions quickly. Your son's Nintendo Switch charges slowly through the dock. USB Prober shows whether the cable supports fast charging or if he needs an upgrade. Your daughter's phone charges in 15 minutes on one charger but takes an hour on another. USB Prober explains the difference.