Fact Checked

What is a USB Dongle?

R. Kayne
R. Kayne

Many devices smaller than a pack of gum can slip into the Universal Serial Bus (USB) port of a computer. These devices are called USB dongles and add features to the computer or machine that were not built in by the manufacturer. This can include the ability to connect to wireless networks, transfer data from the computer to the dongle, and increase a system's security.

Basic Features and Name

A USB dongle.
A USB dongle.

In general, a USB dongle is small enough to fit into a pocket and someone can plug it into the USB port on a computer. Sometimes they include a wire that can be plugged into another device or computer, though many of them function as stand-alone hardware. The name "dongle" comes from uncertain origins, but likely originated in terms of security hardware, and has extended in use to other devices.

Memory and Storage

A Bluetooth® dongle.
A Bluetooth® dongle.

A storage or memory USB dongle, also called a memory stick, provides a convenient means to pass files between computers or devices. The memory stick contains a rewritable solid-state memory chip that does not require power to retain its contents. As capacities have grown and price has dropped, these portable, plug-and-play storage drives have replaced floppy disks and even writable discs for exchanging files and archiving data.

Wi-Fi® Connections Through a Dongle

A wireless internet adapter.
A wireless internet adapter.

Another type of USB dongle can add Wi-Fi® functionality to a computer to provide wireless Internet connectivity. Most desktop computers can accommodate internal Wi-Fi® cards, but some laptops and notebooks rely on external gadgets for wireless connections. The USB Wi-Fi® dongle comes in many models with the most basic model working with Operating System (OS) software to locate nearby wireless networks and access them.

A HSDPA modem and USB cord.
A HSDPA modem and USB cord.

A Wi-Fi® finder or scanner can also come in the form of a USB dongle, allowing a person to scan for free public networks while mobile. This device often features Light-Emitting Diodes (LEDs) that light without having to boot the laptop, indicating a wireless network has been detected. A series of LEDs can indicate signal strength, letting the user glance at the dongle and instantly see if accessibility increases or decreases. Different colored LEDs might also specify encrypted or unencrypted networks.

Bluetooth® Devices and Dongles

Plug-and-play storage drives have replaced floppy disks.
Plug-and-play storage drives have replaced floppy disks.

USB Bluetooth® dongles let a device connect to a Personal Area Network (PAN). Bluetooth® has become increasingly useful for passing data between cell phones and computers, syncing Personal Digital Assistants (PDAs) to laptops, and making hands-free mobile phone calls. Bluetooth® users can often activate and connect to a PAN with virtually no networking experience, and without the use of extra cables.

Laptop users, for example, might want to make their printer and laptop Bluetooth®-enabled. A USB Bluetooth® dongle can wirelessly link the two machines in a few seconds, allowing the user to send print jobs to the printer without having to connect the devices with a cable. Some newer printers include built-in wireless functionality, but a USB dongle may be needed for a computer or other device to connect to it.

Security Devices

There are also proprietary USB dongles that act as a security token to authenticate software in order to protect it from use by unauthorized persons. These types of devices can verify credentials or supply a password to a Virtual Private Network (VPN) for field personnel, for example, operating on a secured system. Without the USB security dongle and proper credentials, a person cannot log into the network or access the software under its protection. There are even devices used to access computer terminals, locking the system unless the user has connected the appropriate USB dongle to it.

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Discussion Comments


I think of the term "dongle" as applying more wireless usb receivers for other devices, like keyboard, mouse, wifi. I wouldn't usually refer to a USB thumb drive (or flash drive) as a dongle, though it may still be technically correct.

Then again, a VPN dongle is commonly referred to as a dongle -- popular usage is kind of random sometimes.


Isn't this the same as what we call a 'flash drive'?


@Fastpaced: That's right, it's possible to mold these in any size or shape you can imagine! Did you know it's even possible to hide a USB drive in a pen or business card?


The term 'dongle' is very (relatively) old. We used it back in the late Fifties and early Sixties in UK to mean any blob that sat on a cable and did something to what was flowing in the cable. I wasn't a techo in those days, when a techo was very different from a user, so I cannot give you an example. Dongle was just one of those words like Phred that arose then. Liz


I need a USB dongle adopter to connect a USB wireless net into my Toshiba Android tablet. Where I will get this USB dongle adopter either in India or elsewhere?


@sinefey: I am just as astonished as you were to be finding out about this term today for the first time ever!


how do I transfer photos from my PC to my dongle? I am upgrading my system.


USB dongles can be shaped like many things to make them look more aesthetically appealing. I've seen ones manufactured to look like popular cartoon characters and sports equipment. These memory sticks can be attached to key chains and zippers on backpacks for convenience and easy access.


Am I the only one who has never heard a USB drive called a dongle?

I've never even seen advertising, or for that matter at the store on the price tag, that used the word dongle.

Kind of makes you smile though doesn't it!

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    • A USB dongle.
      By: mrchilli
      A USB dongle.
    • A Bluetooth® dongle.
      By: Dan
      A Bluetooth® dongle.
    • A wireless internet adapter.
      By: Scanrail
      A wireless internet adapter.
    • A HSDPA modem and USB cord.
      By: Petr Malyshev
      A HSDPA modem and USB cord.
    • Plug-and-play storage drives have replaced floppy disks.
      By: Iakov Kalinin
      Plug-and-play storage drives have replaced floppy disks.