The basic definition

A dongle is a small hardware device that plugs into a port on your computer, TV, or other equipment to add a capability that is not built in. The word covers a wide range of devices – anything from a USB WiFi adapter to a mobile broadband stick to an HDMI streaming device to a hardware security key.

The common thread is the form factor: a dongle is compact, bus-powered (it draws power through the port it is plugged into), and purpose-built for one specific job.

Types of dongle

The term dongle covers several distinct product categories, each solving a different problem:

• WiFi dongles – USB adapters that add wireless networking to a desktop PC, older laptop, or smart TV. The most common type in consumer electronics.
• 4G and 5G dongles – USB modems that connect to a mobile network and create internet access anywhere there is cell coverage. Also called mobile broadband sticks.
• USB-C hubs and adapters – Multi-port expanders that give you back the ports removed from modern thin laptops. Often called dongles informally.
• Bluetooth dongles – USB adapters that add Bluetooth to devices that lack it, or upgrade older Bluetooth versions.
• HDMI streaming dongles – Devices like the Amazon Fire Stick or Google Chromecast that plug into a TV HDMI port and stream content.
• Security dongles – Hardware authentication keys (like YubiKey) that provide two-factor authentication or encrypted storage.
• IoT and M2M dongles – Industrial USB LTE modules used in connected devices, vending machines, fleet tracking, and other machine-to-machine applications.
• Software licence dongles – HASP keys and similar devices that must be plugged in for licensed professional software to run. Common in CAD and broadcast.

Where the name came from

The word dongle dates to the early 1980s. Its origin is disputed – some sources attribute it to a corruption of “dangle”, describing how these devices hung from a port. Others suggest it was coined at Rainbow Technologies, a manufacturer of software protection keys.

The term originally referred exclusively to software protection devices. Over time it broadened to cover any small plug-in hardware peripheral. By the 2010s it was commonly used for USB mobile broadband sticks, and today it applies loosely to any compact plug-in adapter.

Which dongle do I need?

The right dongle depends on what you are trying to connect. Use the categories below as a starting point:

• Need wireless internet on a desktop PC or older laptop? You need a WiFi dongle.
• Need internet on the move, away from broadband? You need a 4G or 5G dongle.
• New laptop with only USB-C ports? You need a USB-C hub.
• Need Bluetooth for wireless headphones or peripherals? You need a Bluetooth dongle.
• Want to stream Netflix on an older TV? You need an HDMI streaming dongle.

Not sure? Use the Dongle Finder – answer three questions and we will point you in the right direction.