What Is USB OTG and What Does It Do?

USB On-the-Go lets your Android read data from USB devices

USB OTG storage settings in Android

If you've spent any time shopping for smartphones or tablets and looking at the packaging, you've likely seen mention of USB OTG (also called USB On-the-Go). It's a handy functionality that allows you to connect USB peripherals to your phone, tablet, or other devices just as you would to a computer.

What Is USB OTG?

USB OTG serves as an indicator on devices capable of connecting to and controlling external USB peripherals or connecting to another device and acting as a peripheral themselves. They achieve this functionality using a single USB port, according to USB.org.

This is easier to understand with a clear example. In general, USB connections start from a computer (the host) and link to another device (the peripheral), such as a printer, mouse, keyboard, or USB flash drive. A device that supports USB OTG can function as both the host or the peripheral.

A common implementation of USB OTG is Android smartphones. If you plug one into your computer, the computer will be the host and the phone will be the peripheral. You'd use your computer to manage files on the phone, but with USB OTG, you could also connect that same Android phone to a USB flash drive, and the phone would then serve as the host and control the flash drive as the peripheral.

How to Determine if Your Device Supports USB OTG

A lot of popular Android phones support USB OTG. So, if you have one of the best Samsung phones, you're probably in luck. If you're uncertain, there are a couple of ways you can check to see if your device supports USB OTG.

The first and simplest indicator of whether your device supports USB OTG is the presence of the USB OTG logo on the product packaging.

USB On-The-Go logo

If you no longer have your product packaging, and want to check for support before buying USB OTG adapters or peripherals, you can install a USB OTG checker app (like this one from the Google Play Store) onto your Android device. When you run the app, it will check for USB OTG functionality, and let you know which features work.

You may also be able to find USB OTG information in the settings of your device. This will vary widely by device, but for some Android devices, it may be under the System section of settings. And, if your device lists any USB settings, it would likely be found in there.

What You Can Do With the USB OTG Function

What you can do with USB OTG varies by device. The specification doesn't require all devices to support all the same peripherals. For instance, a camera with USB OTG may support connecting to a printer, but not to an Xbox controller.

But, for many Android devices, there are loads of useful options. If you're trying to use an Android tablet as a laptop, you could use USB OTG to connect a USB hub, then a mouse and keyboard. You could also connect a video game controller. Support for these peripherals could be extra handy if you want stream video games with a service like Google Stadia.

If you don't have a lot of internal storage on your device, USB OTG can support connecting USB flash drives or even external hard drives to dramatically increase the amount of storage you have available. Some USB OTG connections can even support USB 3.0 speeds. Some external drives are made to plug directly into phones to serve as USB OTG storage, while other drives with a standard USB-A connector may require a USB OTG adapter.

Do iPhones Support USB OTG? 

No. iPhones and iPads don’t support USB OTG, but they do offer somewhat similar functionality, and better support for external storage is available in iOS 13. Here are some ways you can connect USB devices to an iPad.