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USB-C is a reversible connector that can be used to transmit data, video and audio signals, and PCI-E signals, among others. It also supports much faster charging speeds than USB-A --- up to a few hundred watts --- with USB Power Delivery.

USB-C is the emerging standard for charging and transferring data. Right now, it's included in devices like laptops, phones, and tablets and --- given time --- it'll spread to pretty much everything that currently uses the older, larger USB connector.

What Is USB Type-C?

USB Type-C, usually just called "USB-C," is a new USB connector designed to better accommodate modern needs. It was designed with a huge number of improvements over previous USB cables (and ports). Here's the quick list of everything new and improved:

  • A new, compact connector that is fully reversible
  • Supports higher power delivery
  • Supports DisplayPort Alt Mode
  • Up to four PCIe 4.0 lanes
  • Audio transmission to replace 3.5mm audio jack
  • Compatible with Thunderbolt
  • Compatible with the latest USB standard (USB4 v2.0) and backward compatible with USB 2.0

Though the specifications for USB-C were first published in 2014, adoption has been gradual. USB-C is now shaping up to be a real replacement for not only older USB standards, but also other standards like Thunderbolt and DisplayPort. USB-C is closely intertwined with other new standards, as well --- like USB 4 for faster speeds and USB Power Delivery for improved power delivery over USB connections.

USB-C Features a New Connector Shape

USB Type-C has a new, tiny physical connector --- roughly the size of a micro-USB connector. The USB-C connector itself can support various exciting new USB standards like USB4 v2.0 and USB power delivery (USB PD).

The standard USB connector you're most familiar with is USB Type-A. Even as we've moved from USB 1 to USB 2 and on to modern USB 3 devices, that connector has stayed the same. It's as massive as ever, and it only plugs in one way (which is obviously never the way you try to plug it in the first time). But as devices became smaller and thinner, those massive USB ports just didn't fit. This gave rise to lots of other USB connector shapes like the "micro" and "mini" connectors.

USB-A, microUSB, USB-C, and USB-B cables.
Hannah Stryker / How-To Geek

This awkward collection of differently shaped connectors for different-size devices is finally coming to a close. USB Type-C offers a new connector standard that's very small. It's about a third the size of an old USB Type-A plug. This is a single connector standard that every device should be able to use. You'll just need a single cable, whether you're connecting an external hard drive to your laptop or charging your smartphone from a USB charger. That one tiny connector is small enough to fit into a super-thin mobile device, but also powerful enough to connect all the peripherals you want to your laptop. The cable itself has USB Type-C connectors at both ends---it's all one connector.

USB-C provides plenty to like. It's reversible, so you'll no longer have to flip the connector around a minimum of three times looking for the correct orientation. It's a single USB connector shape that all devices should adopt, so you won't have to keep loads of different USB cables with different connector shapes for your various devices. And you'll have no more massive ports taking up an unnecessary amount of room on ever-thinner devices.

USB Type-C ports can also support a variety of different protocols using "alternate modes," which allows you to have adapters that can output VGA, DisplayPort, or other types of connections from that single USB port. Apple's USB-C Digital Multiport Adapter is a good example of this, offering an adapter that allows you to connect an HDMI, VGA, larger USB Type-A connectors, and smaller USB Type-C connector via a single port. The mess of USB, HDMI, DisplayPort, VGA, and power ports on typical laptops can be streamlined into a single type of port.

USB-C, USB PD, and Power Delivery

The USB PD specification is also closely intertwined with USB Type-C. A USB 2.0 connection provides up to 2.5 watts of power---enough to charge your phone or tablet, but that's about it. The USB PD specification v3.1 supported by USB-C ups this power delivery to an enormous 240 watts. It's bi-directional, so a device can either send or receive power. And this power can be transferred at the same time the device is transmitting data across the connection. This kind of power delivery could even let you charge a laptop, which usually requires up to about 60 watts.

Apple's MacBook Air and Google's Chromebook Pixel both use their USB-C ports as their charging ports. USB-C could spell the end of all those proprietary laptop charging cables, with everything charging via a standard USB connection. You could even charge your laptop from one of those portable battery packs you charge your smartphones and other portable devices from today. You could plug your laptop into an external display connected to a power cable, and that external display would charge your laptop as you used it as an external display -- all via the one little USB Type-C connection.

There is one catch, though --- at least at the moment. Just because a device or cable supports USB-C does necessarily mean it also supports USB PD. So, you'll need to make sure that the devices and cables you buy support both USB-C and USB PD.

USB-C, USB 4, and Transfer Rates

The naming conventions for USB are notoriously complicated. They've been renamed, decimals and numbers have been tacked on the end, and retroactively merged into one name. The situation makes buying a cable and knowing what to expect difficult. Here's what you need to know.

USB 2.0 is USB 2.0, and anywhere you see it you can be sure that you'll have a maximum transfer speed of 480 megabits per second.

USB 3, on the other hand, is a naming catastrophe. You can be sure that anything with a USB 3.x label will have a transfer speed of at least 5 gigabits per second, but it could be as fast as 20 gigabits per second. When you're buying a USB cable, check out the product description carefully --- somewhere it'll actually state the transfer speed it supports.

USB 4 has tried to avoid falling into the naming trap. There are only two versions of USB 4: USB 4, and USB 4 v2.0. Regular USB 4 has a maximum transfer rate of 40 gigabits per second, and USB v2.0 has a maximum transfer rate of 80 gigabits per second.

USB Type-C isn't the same thing as USB 3.2 or USB 4, though. USB Type-C is just a connector shape, and the underlying technology could just be USB 2, USB 3, or USB 4. In fact, Nokia's N1 Android tablet uses a USB Type-C connector, but underneath it's all USB 2.0 --- not even USB 3.0. However, these technologies are closely related. When buying devices, you'll just need to keep your eye on the details and make sure you're buying devices (and cables) that support the USB standard you need in a device.

USB-C to DisplayPort

DisplayPort --- as the name might suggest --- is specifically designed to transmit video signals between your computer and a display of some kind, like a monitor, TV, or projector. Typically, that requires both a DisplayPort port, and a DisplayPort cable, but USB-C changes that.

USB-C includes support for DisplayPort Alt Mode, which allows USB-C cables to transmit video signals directly between your computer and display via the DisplayPort standard. That means your ultra-thin laptop doesn't need a chunky DisplayPort port, manufacturers can opt for a small USB-C port instead.

You can use a USB-C to USB-C cable to connect a PC to a display if both devices have the appropriate USB-C ports, or a USB-C to DisplayPort cable if your display lacks a USB-C port.

DisplayPort 2.1 has been largely designed to play nicely with USB 4 (and USB 4 v2) --- that means you'll be able to drive an 8K monitor at 60Hz with HDR10 (uncompressed) over a single USB-C cable if you've got the right hardware for it, multiple 4K monitors, or even a 16K display with digital stream compression.

USB-C to HDMI

HDMI is the most popular audio video interface today. It is found on most every TV, monitor, GPU, projector, and motherboard. Even many laptops --- which get thinner and have fewer ports every generation --- have retained their HDMI ports.

HDMI Alt Mode, which allows you to send HDMI signals directly over a USB-C cable does exist, but it isn't in use, and a report from CES 2023 suggests the feature will be getting the axe entirely. But don't worry --- you can still connect a USB-C cable to HDMI if you want.

So, how does it work if HDMI Alt Mode is dead? DisplayPort Alt Mode, of course! Existing USB-C to HDMI adapters are sent a signal from the USB-C port using DisplayPort Alt Mode, then the adapter itself converts DisplayPort to HDMI.

A USB-C to HDMI adapter.
Justin Duino / How-To Geek

In most situations, you probably won't notice the difference between native HDMI Alt Mode and the more convoluted DisplayPort Alt Mode to HDMI conversion method, but there are a few important differences. First, the USB-C to HDMI adapter is active, which means that it consumes electricity while converting the signal. That probably isn't a dealbreaker, but it is something to be aware of. Second, it introduces a potential bottleneck. Not all converters can handle the latest DisplayPort or HDMI standards, which might mean that you get worse performance than you would otherwise expect. This probably won't be an issue unless you're trying to drive a 4K display faster than 60 Hz, thankfully.

Is Thunderbolt the Same As USB-C?

No, but they are related. Thunderbolt is technically a connectivity standard, much like USB itself is. The Thunderbolt standard defines how much power and data a port and cable must be able to transfer, as well as mandate some other features, like video and PCIe functionality.

Thunderbolt 3 and Thunderbolt 4 both use USB-C connectors and USB-C ports for their physical connections. Since they share a connector, modern USB standards (like USB 3.2, USB 4, and USB 4 v2.0) are designed to be interoperable with Thunderbolt.

In other words, you can take a USB external SSD, plug it into a Thunderbolt port with a USB-C cable rated for USB 3.2 standards, and expect it to work correctly. You can take any Thunderbolt 3 or Thunderbolt 4 cable and use it to connect USB devices with USB-C ports and they'll work correctly.

Almost any arrangement of USB and Thunderbolt ports, cables, and peripherals will work. The most significant difference is the minimum transfer speed. Thunderbolt 4 requires a minimum transfer speed of 40 gigabits per second, whereas USB 4 only has a minimum of 20 gigabits per second.

Related: Thunderbolt vs. USB-C: What's the Difference?

Backward Compatibility

The physical USB-C connector isn't backward compatible, but the underlying USB standard is. You can't plug older USB devices into a modern, tiny USB-C port, nor can you connect a USB-C connector into an older, larger USB port. But that doesn't mean you have to discard all your old peripherals. USB 4 (and USB 3.x) is still backward-compatible with older versions of USB, so you just need a physical adapter with a USB-C connector on one end and a larger, older-style USB port on the other end. You can then plug your older devices directly into a USB Type-C port.

Realistically, many computers will have both USB Type-C ports and larger USB Type-A ports for the immediate future---like Google's Chromebook Pixel. You'll be able to slowly transition from your old devices, getting new peripherals with USB Type-C connectors. Even if you get a computer with only USB Type-C ports, like Apple's MacBook Air, adapters and hubs will fill the gap.

Check Your USB-C Cables and Ports

All of this sounds great --- a cable that can deliver power, video, audio, ethernet, and USB functionality all at once? What isn't to love?

As with all things USB, things are a little messy. Top-shelf USB cables and the most sophisticated ports can do everything we've listed. However, not every USB-C cable or USB-C port will be built to include that functionality.

Implementing all of those features on a USB-C port is more expensive than a simple charging port with USB 3.2 data rates, for example, so manufacturers tend to only include one or two fully featured USB-C ports on their devices.

Something similar applies to USB-C cables. USB-C cables that are rated for the best data rates and the newest USB Power Delivery standards are more expensive and typically noticeably thicker than their cheaper counterparts.

USB Type-C is a worthy upgrade. It's making waves on the newer MacBooks and some mobile devices, but it's not an Apple- or mobile-only technology. As time goes on, USB-C will appear in more and more devices of all types. USB-C is reportedly even slated to replace the Lightning connector on Apple's iPhones. Lightning doesn't have many advantages over USB Type-C besides being a proprietary standard Apple can charge licensing fees for. Imagine a day when your Android-using friends need a charge, and you don't have to give the sorrowful "Sorry, I've just got an iPhone charger" line!