I never leave the house without this $8 gadget, and it's not just for charging my phone

Let's set the scene: your phone or some other gadget is on its last battery percentage, and even though there's a USB port nearby, you don't actually have a cable to use it. I've run into that situation more times than I can count, so I picked up a tiny USB-C keychain cable that I can carry everywhere, and it's been way more useful than I ever could've expected.

The best charging cable is the one you have when you need it

Convenience is what matters most

One of the main reasons why I bought a USB-C to USB-C keychain cable is also the most obvious—charging my devices.

Thanks to USB-C now seeing widespread adoption (at least for gadgets, anyway), I can charge a wide variety of devices in a pinch using nothing but my OnePlus 15's beefy 7,300mAh silicon-carbon battery and this USB-C cable.

Although some of my accessories, like my earbuds, do have a Qi wireless charging case that I can reverse charge with my phone, not all of them do.

I recently ran into a situation while traveling where I had to use my keychain flashlight to illuminate a shadowy park trail, but it ran out of battery. Thankfully, I had my USB-C to USB-C keychain cable handy and was able to plug the flashlight in to run it, getting a significantly more powerful light compared to the puny flashlight built into my camera.

Aside from accessories, I can also use the cable to charge someone else's phone. While most phones do support Qi wireless charging, it can be a hassle to set up if both phones have cases, and even then, it's painfully slow—despite the spec sheet saying my phone outputs up to 10W in reverse charging mode.

On the other hand, reverse wired charging from my phone is limited to just 5W, but I've found it still charges other people's phones much more quickly and reliably. My wife's aging Samsung Galaxy S23+ frequently runs out of juice when we're out and about, so I end up topping it up with this cable and my phone fairly often.

And should my phone ever run out of juice itself, the USB-C cable is super handy to have around. Even if I don't have a wall charger at hand, there's a very good chance I can still find a public USB-C port somewhere for charging, whether it's my laptop when I'm working on the go, a coffee shop, an airport, or, quite often, on public transport like a train or bus.

It's worth pointing out that many public USB ports are still USB-A. Fortunately, if you plan ahead and also bring a USB-A to USB-C adapter , nothing can stop you from charging your phone and gadgets on the go. I always carry a USB-A to USB-C adapter in my wallet, which means I can turn just about any public USB port into a charging source thanks to my handy keychain cable.

It's not just for charging, it's also great for file transfers

A tiny cable that does more than you'd expect

Although I primarily bought the USB-C cable to charge my devices, it's not the only reason I keep it on hand. It also supports data transfers.

While you can use the cable to move files between two phones, I don't normally do that, as Quick Share is heaps faster and more convenient. But if I need to move files between a PC or laptop and my phone when the cloud isn't available (like when I'm traveling), this cable works great in a pinch.

It's not just limited to data transfers, though. In theory, this cable can work in any situation where I might need to establish a data link between my phone and something else, such as a wired Android Auto connection in a rental car, displaying to a monitor, or connecting various other compatible devices like cameras, microphones, controllers, audio interfaces, and more.

I don't fully trust the specs, but that's not the point

It works, and that's what matters

I've already hinted at this above, but I need to make one thing clear about this cheap USB-C keychain cable that I bought: I don't trust the specs the product page claims at all. It says it supports 240W fast charging, 40Gbps (USB4) data transfer rates, and up to 8K@60Hz video output on compatible USB-C displays.

I haven't been able to verify the video output claim because I don't currently have access to a USB-C display, but I can at least confirm that it can fast charge my OnePlus 15 when I use the original 120W SuperVOOC charging brick (even though I have to use a USB-A to USB-C adapter).

As for data transfers, this cable apparently supports USB4's 40Gbps maximum bandwidth. I don't have anything else equipped with USB4 to test it, but it transfers files between the USB 3.1 USB-C port on my PC and my phone reasonably fast. I tried copying 20 images from my phone to my PC for this article, and it only took 3–4 seconds to finish.

Even if I got ultra-slow file transfers and charging speeds, the important thing is that always having this little cable with me gives me the option in the first place. When my phone or earbuds are out of juice, or if I need to transfer an essential document to someone's laptop in a hurry, this cable does it—which is all I need.

While my affordable cable can absolutely get the job done, if you're looking for a more premium product and are willing to pay for it, better options exist. The Nomad ChargeKey is an awesome premium option at $25.

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Small enough to carry anywhere, useful enough to keep

I'm a huge fan of practical keychain accessories, and this USB-C cable is honestly giving my tiny Swiss Army knife a run for its money. This small, unassuming tool is surprisingly versatile—I can use it for everything from topping up my phone and earbuds to copying important files to my laptop. Put simply, it solves a shocking number of problems in a small, affordable package.