Recognising USB connectors: which cable do you need?
The shape of the connector decides both ends of the cable. The flat, rectangular USB-A is the computer and charger side; the almost square USB-B belongs to printers and scanners; the small oval USB-C to today’s phones and laptops; the trapezoid micro USB to older phones and external hard drives. Speed and charging power do not come from the shape but from the cable’s standard: USB 2.0, 3.0 or USB4, and 60, 100 or 240 W.
The connectors, by shape
Look at the socket on your device and find it in the rows. The fourth column shows a cable or two from our range.
| Connector | What it looks like | Where you find it | Cable from our range |
|---|---|---|---|
| USB-A | flat rectangle, plugs in one way only | computer, charger, hub, USB stick | A / A: AK-USB-06 (USB 2.0, 1.8 m), AK-USB-10 (USB 3.0, 1.8 m); extension: AK-USB-19 (3 m) |
| USB-B | almost square, with two bevelled corners | printer, scanner, some audio interfaces | A / B: AK-USB-12 (3 m), AK-USB-18 (5 m); USB 3.0: AK-USB-09 (1.8 m) |
| micro USB (micro-B) | small trapezoid, goes in one way only | older phones, power banks, e-readers, small devices | AK-USB-47 (magnetic, 1 m); micro USB / USB-C: AK-USB-16 (1 m); USB-A socket for the phone (OTG): AK-AD-34 |
| micro USB 3.0 | wide, two-part micro connector | 2.5-inch external hard drive | USB-A / micro-B 3.0: AK-USB-13 (1.8 m); for a USB-C laptop: AK-USB-44 (1 m) |
| USB-C | small oval, plugs in either way | today’s phones, laptops, tablets, monitors, docks | USB-A / USB-C: AK-USB-59 (1 m), AK-USB-60 (1.8 m); USB-C / USB-C 60 W: AK-USB-40 (1 m), AK-USB-41 (1.8 m); 100 W: AK-USB-37 (1 m), AK-USB-38 (1.8 m); USB 3.1: AK-USB-15; USB4 40 Gb/s, 240 W: AK-USB-45; USB-A socket to USB-C: AK-AD-47 |
| Lightning | small, flat, plugs in either way; Apple only | iPhones before the iPhone 15, older iPads, AirPods cases | USB-C / Lightning: AK-USB-35 (20 W, 1 m); USB-A / Lightning: AK-USB-31 (1.8 m); four-in-one: AK-USB-52 |
The shape does not tell you the speed
A USB 2.0, a USB 3.1 and a USB4 cable all fit the same USB-C socket, and all of them charge. Data transfer is where they differ a lot: for charging a phone or for a mouse, 2.0 is enough; an external SSD or a dock needs 3.1 or USB4. For a monitor or dock, the cable’s box or name says whether it carries video.
A Thunderbolt cable has the same USB-C plug but belongs between the Thunderbolt ports of a laptop and a dock: AK-USB-33 (Thunderbolt 4, 50 cm, passive). The USB 3.0 micro connector is wider because it has more contacts; an old micro USB cable fits it, but only at 2.0 speed.
Charging: 60, 100 or 240 W
The wattage of a USB-C / USB-C cable is the ceiling the cable carries. Choose the cable for the USB Power Delivery power supported by the charger and the device: check the wattage on the charger and buy a cable rated no lower. Up to 60 W any USB-C / USB-C cable will do; above 60 W you need a 100 W cable, and the most powerful chargers need a 240 W cable. The shape of the connector does not tell you the data speed or video output either; the cable’s name does.
Which cable for a printer
Desktop printers and scanners have a USB-B socket, and the computer side is USB-A: that is the USB A / B cable, AK-USB-12 in 3 m and AK-USB-18 in 5 m. If there is no cable in the printer’s box, this is the one. For a USB-C laptop, connect its end with the AK-AD-47 adapter.
Which cable for an external hard drive
A 2.5-inch external hard drive usually has a micro USB 3.0 socket: AK-USB-13 for a USB-A computer, AK-USB-44 for a USB-C laptop. Newer external SSDs have a USB-C socket; they take a USB 3.1 or USB4 USB-C / USB-C cable, for example AK-USB-15.
The full range, with prices and spec tables: USB cables and adapters.
Frequently asked questions
Which cable does a printer need?
A USB A / B cable: the A end goes into the computer, the almost square B end into the printer. It comes in 3 and 5 metres; for a USB-C laptop you also need an adapter with a USB-A socket.
What is the difference between micro USB and USB-C?
Micro USB is trapezoid and goes in one way only; USB-C is oval, plugs in either way and carries more power. The two are not interchangeable, but there are micro USB / USB-C cables.
Does a 60 W USB-C cable charge a laptop?
Yes, if the laptop’s charger is 60 W or less. A stronger charger calls for a 100 W cable, the strongest ones for 240 W USB4.
Are all USB-C cables the same?
No. The shape is the same, the standard is not: a USB 2.0 cable charges and carries data slowly, 3.1 and USB4 are for external SSDs and docks. The cable’s name says which it is.
Does a Lightning cable work with a new iPhone?
No. From the iPhone 15 on the phone has a USB-C socket, so the phone end of the cable is USB-C; the other end depends on the charger: a USB-C charger takes a USB-C / USB-C cable, a USB-A charger a USB-A / USB-C cable. Lightning is for earlier iPhones and older iPads.
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