Adapters simplify the sometimes-messy process of connecting things to our computers. I regularly travel, and I’ve found there are three USB adapters that get me through most of my connection problems.

If you, for example, suddenly need to use a new accessory at a client’s office, or get power at an airport, these adapters will get you through. And they are very affordable.

3 must-have travel adapters

Understanding the various USB port types

None of these suggestions are going to make sense if you don’t know what the various USB port types are. (You might be surprised how many people don’t.)

USB-A is the largest, oldest version of USB still in frequent use. It’s not reversible. The cables plug in only one way, and it seems you have to flip them over Every. Single. Time. The standard has been around since the 1990s, but you still see it everywhere.

USB-C is smaller and it is reversible. Apple has put these in every Mac and most iPads for years. USB-C is supposed to completely replace USB-A, but that’s taking a long, long time.

Lightning is the port in the iPhone and budget iPad. It’s proprietary but Apple refuses to give it up.

A USB-A to USB-C adapter is very useful

The single most useful adapter in my gear bag lets me plug USB-A connectors into a USB-C port.

Suppose someone hands you a thumbdrive full of images to transfer to your Mac, but the drive has a USB-A connector. With the right adapter, you can plug the drive into your computer. Problem solved.

Or maybe you need to connect two USB-C devices and all you have is a cable with USB-A on one end and USB-C on the other. Attach this adapter and you have what you need.

Let me recommend the Satechi USB-C to USB-A Adapter ($8.99).

Buy from: Amazon

A USB-C to USB-A adapter is great, too

What’s good for the goose is good for the gander. Sometime you need to plug a USB-C accessory into a USB-A port. Fortunately, there’s an adapter for that, too.

For me, this usually comes up when I need to let someone else use one of my accessories. I carry files on a Kingston DataTraveler Max that has a USB-C port. If I want to give some files to someone, and their Windows laptop still uses USB-A, a simple adapter solves the problem.

This adapter proves useful with charging cables, too. I carry a USB-C cable to juice up my iPad Pro, but many public charging stations offer only USB-A ports. I attach the adapter to my cable and plug in.

Consider the Satechi USB-C to USB-A adapter ($6.99) for this job. I have one and it works well.

Buy from: Amazon

USB-C to Lightning adapter is an iPhone user’s friend

As a traveler, carrying a cable to charge only the iPhone is a waste of space. That’s where the USB-C to Lightning adapter comes in. With it, a MacBook’s or iPad’s USB-C charging cable can be used with the iPhone, too.

I got a three-pack from a random company for $6.99. I tested them and they work great.

Buy from: Amazon

Honorable mention

The three adapters I already mentioned are the most useful for me. But there are other options for you to consider.

USB-C to USB-C

I occasionally run into a situation where my charging cable won’t reach to the electrical socket where the power adapter is. When this happens, I pull out a USB-C to USB-C adapter and connect two charging cables together. It’s not a perfect solution, but it works in a pinch.

Here’s one from Cellularize. I haven’t tested this particular model, but it’s only $6.99 for a pack of two. (I got mine so long ago I can’t remember who made it.)

Buy from: Amazon

HDMI to USB-C

The world is full of HDMI monitors, but only the most recent MacBooks come with built-in HDMI ports. Get an HDMI to USB-C adapter and you’re ready to make any of those monitors into a second screen for your laptop or iPad.

I reviewed the Plugable USB-C to HDMI Adapter ($14.95), and it works well.

Buy from: Amazon

Get a bunch of USB adapters

Most of these adapters usually go for around $5, and often you can get several for under $10. The HDMI to USB-C one is an exception, but it’s doing a more complex job.

Anyway, with prices this low, you should have a few of each. You might accidentally leave one behind. Or need two of them at the same time.

But you should definitely have at least one of the three USB adapters I recommend most: USB-A to USB-C, USB-C to USB-A, and USB-C to Lightning. They can be lifesavers.