USB On-The-Go, usually shortened to OTG, is a feature that lets a device such as a phone or tablet act as a USB host instead of only being a peripheral. Normally a phone is the device being charged or synced by a computer, but with OTG it can take on the controlling role itself.
With OTG, a phone can connect directly to a USB flash drive to browse and copy files, plug in a USB keyboard or mouse for easier typing, or connect a card reader, all without a computer in between. On phones with USB-C, this often just needs a small adapter or a USB-C to USB-A cable, since the electrical signalling for OTG is built into the port.
Not every phone or accessory supports OTG, and some accessories draw more power than a phone can comfortably supply on its own, so a powered hub is sometimes needed for demanding devices. See our guide to USB OTG on phones for setup details.
