Published Aug 1, 2026, 11:00 AM EDT
Oliver has been writing about mobile and the wider technology space for more than a decade with bylines on TechRadar, CNET, Inverse, and more.
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If you're anything like me, you probably have a drawer full of USB-C cables. USB-C was supposed to be the single connector to rule them all. Capable of powering everything from portable fans to high-powered laptops, and reversible to boot. But its versatility ushered in a new problem.
Gone are the days of trying to plug a USB-A cable in three times before you find the right orientation. But it's been replaced by a game of chance. That drawer of cables is an exercise in guesswork as I try to find one capable of charging my 16-inch MacBook Pro. Some sort of label would be nice.
But it doesn't have to be this way. Everything changed when I got my hands on a USB cable tester, and I haven't looked back.
Identical cables, completely different uses
Unknown data speeds and charging power
The problem with using a single cable connector for everything is that all those cables inevitably look the same. The cable that came free with your earbuds looks just like the one that came with your laptop and can handle over 100W of power. Your no-brand 480Mbps USB 2.0 cable is indistinguishable from the super-fast USB 4 cable that can move 40 gigabits (around 5 gigabytes) of data every single second. And that's before we get into the way high-speed Thunderbolt cables use the same connector — that's for another time.
These cables only look the same, of course; they are very different on the inside. More capable cables tend to be thicker, albeit often imperceptibly so. There's also the e-marker chip. Think of it as the brains of the cable. It's the e-marker chip that tells your devices what the cable is actually capable of, whether that's charging power or data transfer abilities. Any cable that can charge at more than 60W requires an e-marker chip to do so. Any cable that can transfer data faster than USB 2.0 speeds also requires a chip to do so.
That e-marker chip is vital. Even if the cable itself is capable of charging at more than 60W and transferring data at faster than USB 2.0 speeds, it won't do so without that chip. But you can't tell if an e-marker chip is present just by looking at a cable. So while it's good information to know, it won't help you find the right cable come charging time.
For that, you're going to need $15 and an Amazon account.
A bargain at thrice the price
The perfect tool for the job
The answer to my charging problem came in the form of a $15 cable tester. Amazon has tons of them to choose from, and you can spend much more and much less than I did. But I just needed to know how fast a cable could charge my stuff, so I didn't need anything flashy.
A simple USB tester sits between your cable and the device you want to charge. Just make sure to plug your cable into a high-powered USB-C power adapter to remove that variable from your testing. Then check out the tester's display to get that sweet, sweet data.
Most budget-friendly testers will give you three main bits of data. The voltage (V) figure shows whether your device negotiated the standard 5V charging power or was able to upgrade to any of the 9V, 15V, 20V, or higher Power Delivery modes. Next, amperage (A) measures the flow of current through the cable and into the USB tester and device. Finally, the wattage (W) figure shows you the real-time power delivery. It's this figure that you're really interested in.
Testers more capable than mine can go a step further and read the data directly from the e-marker chip itself. This comes with the added bonus of also telling you what the cable is rated for in terms of data throughput as well as charging speed. I just wanted to know which cables would charge my devices the quickest, but I can definitely see how knowing a cable's data transfer speed would be useful.
YEREADW USB-C Tester Power Meter
The YEREADW USB C Tester Power Meter (KWS-2303C) accurately measures voltage, current, and power for USB-C devices, helping diagnose charging issues and verify cable or power bank performance quickly and easily.
Stop guessing, start testing
Perfectly paired with a label maker
My USB cable tester and I have become best buds of late. I set aside some time to go through a few cables every couple of days, test them, and then make a note of their capabilities. But the tester is only part of the equation here. I still wanted to make it quicker and easier to find the right cable when I needed it, so I dug out my label maker and went to town.
Now, I have a drawer full of USB-C cables, each with a label wrapped around it to tell me what it can do. I know one cable can fast-charge my laptop, while another is better suited to charging my AirPods Pro 3. It was a pain to do, sure, but you bet I'll be putting labels on each new cable that comes into our home from here on out.
But I shouldn't have had to do any of this. It's time cables came with a label of their own, or some sort of color coding. But until that happens, I'll be sitting over here. USB tester and label maker in hand.