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USB-B

USB Standard-B

Standard: USB-IF Last updated: 2025-01-21

USB-B was designed to prevent users from connecting two host devices together (which USB doesn't support). The distinct shape makes it obvious which end goes where. While being phased out in favor of USB-C, USB-B remains common on printers, audio equipment, and industrial devices where the larger, more robust connector is actually preferred.

Quick Specifications

Max Speed

10 Gbps

Max Power

4.5W

Pins

9

Reversible

No

⚠️ Common Confusion Points

  • USB 3.0 Type-B has a completely different shape than USB 2.0 Type-B - the top is extended with extra pins
  • USB 2.0 Type-B cables fit into USB 3.0 Type-B ports, but only at USB 2.0 speeds
  • USB 3.0 Type-B cables do NOT fit into USB 2.0 Type-B ports
  • USB-B is always the 'device' end - the host side is USB-A or USB-C
  • Many people call this 'printer USB' but it's used on many other devices
  • USB-B is being phased out - newer devices use USB-C for the device port

Protocols & Versions

Protocol Data Rate Power Max Length
USB 1.1 (1.1) 12 Mbps 2.5W (500mA @ 5V) 5m
USB 2.0 (2.0) 480 Mbps 2.5W (500mA @ 5V) 5m
USB 3.2 Gen 1 (3.2 Gen 1 (formerly USB 3.0)) 5 Gbps 4.5W (900mA @ 5V) 3m
USB 3.2 Gen 2 (3.2 Gen 2) 10 Gbps 4.5W (900mA @ 5V) 1m

USB 1.1 Features

Full Speed

Cable requirements: Any USB-B cable

USB 2.0 Features

Hi-Speed

Cable requirements: Any USB-B cable

USB 3.2 Gen 1 Features

SuperSpeed Different connector shape

Cable requirements: USB 3.0 Type-B cable (has extra pins)

USB 3.2 Gen 2 Features

SuperSpeed+

Cable requirements: USB 3.2 Gen 2 Type-B cable

Connector Specifications

Shape
square with beveled top corners
Pins
9 (2 rows)
Width × Height
11 × 10.4 mm
Depth
16 mm
Reversible
No

Electrical Specifications

Max Voltage
5V
Max Current
0.9A
Max Power
4.5W
Impedance
90Ω differential (SuperSpeed)

Compatibility

Backwards Compatible With

  • USB 1.0
  • USB 1.1

Forward Compatible With

  • USB 3.2 Gen 2

Can Adapt To

  • USB-A (as part of cable)
  • USB-C

Can Adapt From

  • USB-A (as part of cable)
  • USB-C

Common Uses

  • Printers
  • Scanners
  • External hard drives (older)
  • Audio interfaces
  • MIDI controllers
  • Docking stations
  • USB hubs (upstream port)
  • Some monitors (USB hub feature)

Buying Guide

For printers and most peripherals, any USB-A to USB-B cable works. For USB 3.0 devices (external drives, audio interfaces), check if the port has the extended USB 3.0 shape and get a matching cable. USB 2.0 cables are cheaper and more common. Cable quality matters less for USB-B since most devices don't need high power delivery.

Also Known As

USB-B USB Type-B Printer USB

Data Sources