What USB-C cable do I need?

Having recently acquired a new MacBook Pro, I’ve been looking for the proper cables to complement it. Mainly, I want a cable that I can charge both the Mac and other USB-C devices with, as well as use to connect USB-C devices. You would think you just get a USB-C to USB-C cable and be done with it, but it’s not so easy.

There are actually four different USB-C to USB-C cables being sold, and they all support different types of connections:

  1. USB-C Charging cable — This is the standard USB-C cable that the Mac comes with. However, what is not stated is that this is actually a USB 2.0 cable, with USB-C ports and extra pins for faster charging. This cable cannot be used to connect a USB 3.1 disk for example. A dead giveaway of USB 2.0 cables is that it is longer than 1 m (3 feet). USB 3.1 cables must be 1 m or shorter to work.
  2. Belkin USB-C 3.1 cable — This is the USB 3.1 version of the above cable, it supports USB 3.1 data connection (you can note the length is 1 m) and Power Delivery, which means it can charge the MacBook and all other accessories. You can also use this it to power USB 3.1 devices like the new LG UltraFine 4K display.
  3. Thunderbolt 3 cable with PD — Yes, there is a seperate cable for Thunderbolt 3. This is NOT the same as a USB 3.1 cable, as it has extra wires (making it thicker). This is the only cable you can use to connect the LG UltraFine 5K display. Confusigly, this cable also comes in a 2 m version. It is important to note that Thunderbolt 3 cables are not USB 3.1 cables! You can not use this cable to connect the LG 4K display for example, it will only work properly with the 5K display. There are also optical Thunderbolt 3 cables, which have longer length (up to 30 m) but cannot supply enough power for a MacBook.
  4. USB-C 3.1 cable (without USB-PD) — Thankfully Apple does not sell this cable, but there are also USB 3.1 cables that carries data. But do not support USB-PD (power delivery), these cannot be used to charge your new MacBook, but can be used to connect external hard drives as an example. If you buy a USB-C external hard drive it is likely this is the type of cable you get with it.

All in all, this is massively confusing. I would not want to be the Best Buy employee trying to explain what cable you need to buy to plug in your new device, because there is not one cable that supports all alternate modes. Your safest bet is to get the Belkin cable because it supports all regular USB 3.1 features. But it can’t be used for any of the alternate modes (Thunderbolt, DisplayPort, MHL or HDMI).

So why are there four kinds of USB-C to USB-C cables? I think the wish from the standard committee was to not sacrifice the range and slenderness of USB 2.0 cables, but still support the higher data and power rates necessary for USB 3.1. You don’t want a Thunderbolt 3 cable to charge your phone (because it is massive). So to solve this they made alternate cables for different purposes.