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USB Type-C is meant to unify connectors and cable specifications, making it easier to connect devices. But not all cable manufacturers follow the connector's requirements. You can potentially buy cables from manufacturers that don't meet the guidelines for power capabilities and data transfer speeds. That's why some USB-C cables charge faster than others — there are a lot of variables at play. Moreover, not all USB cables are meant to transfer data; some are exclusively for charging, and you end up with a complex landscape to navigate. How do you even tell which cables are which?

Unfortunately, while there is an easy way to tell whether USB-C cables can handle data, it's not a foolproof method. When choosing a cable, you should look for the SuperSpeed (SS) logo or a lightning bolt symbol on the connector. SuperSpeed 5, 10, 20, and 40 denote the transfer rates for data transfers between devices. A USB-IF certification logo is also a good sign if you see it printed on the cable, connector, or packaging. It means the cable was compliance tested for quality. But these logos or labels don't always show up.

Other indicators include the cable length (longer cables are only for charging), missing pins inside the connector (which can be tough to discern), and the inclusion of an e-mark chip or power delivery (PD) functionality. The best and simplest way to check is to use the USB-C cable to connect two devices, such as a phone and PC, and see if data transfer is available. As a general rule, you should only buy USB-C cables from reputable brands.

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If you were to take a USB-C data cable and a charging cable and rest them side-by-side, they might look identical. But inside the connectors are mechanical pins, or contact points, and depending on the type of cable, they're arranged in different configurations. Both data and PD cables have extra pins to support the increased voltages and data channels. Data and high-power delivery cables are designed and manufactured differently, as the lack of these extra pins is what limits data transfers, high speeds, and better power delivery — so you can charge your devices faster. Occasionally, those pins are also only available on one side of the connector, which is a reason why you're probably using your USB-C ports wrong, despite the interchangeable design. That's why choosing the right cable for your intended application is important.

So, why have charging-only cables? Sometimes, they're more convenient. These USB-C cables tend to be cheaper, because they are less capable, but also, charging cables are usually longer. The cable length can impact performance, causing signal degradation for data transfers, slowing transfer speeds, and reducing power efficiency. But it can be a viable trade-off when you need to plug your device into an outlet that's further away. One of the common myths about USB-C ports is that they all support fast-charging. That's not so. Moreover, charging-only cables are typically not as thick, because they don't need the additional wiring for data transfers, so they're ideal for travel or portable use. Besides, you likely don't always need a data transfer cable. But charging and a power supply are almost always necessary for electronics.