USB Type B Printer Cable: The Square Connector, Identified and Explained
Quick answer / TL;DR: Short answer: the USB Type B connector is the square, beveled-corner plug on the printer's side of a standard USB A to B printer cable – the computer takes the flat USB-A end, the printer takes the USB-B end. It is a data connector (carrying the print job), full-size B on most printers, and the smaller USB mini-B on some older printers, scanners, and cameras. Match the printer-side shape to the cable's B end.
The 'USB Type B' in a USB Type B printer cable names the connector on the printer's side of the link – the squarish plug with slightly beveled corners that most printers take. It is the device-side half of the standard A-to-B printer cable, and it is the shape that distinguishes a printer's USB port from the flat USB-A ports on the computer. Knowing the USB-B shape – and its smaller cousin, the USB mini-B – is what lets you pick the right cable for the printer in front of you, and avoid the wrong end at the shop.
This guide identifies the USB-B connector, explains its place in the A-to-B printer cable, contrasts it with the USB-A and the mini-B, and covers the cases where the printer side is a mini-B rather than a full-size B.
Identifying the USB-B Connector
| Connector | Shape | Where you find it |
|---|
| USB-A | Flat, rectangular | The computer's ports (the host side) |
| USB-B | Square with beveled corners | The printer's USB port (the device side) |
| USB mini-B | Smaller, trapezoid-ish | Older printers, scanners, cameras |
| The B and mini-B are the device-side shapes; the A is the host-side shape |
The USB-B is the square, beveled plug – distinct from the flat A and from the smaller mini-B. At the printer's port, that square shape is what you are matching the cable's device end to.
Its Place in the A-to-B Printer Cable
- The A-to-B printer cable is named for its two ends: USB-A (computer) and USB-B (printer)
- The B end is the device half – it goes into the printer's square USB-B port
- The cable carries the data pair, so the B end is a data connector, not power
- The B end's shape keying means it fits the printer's port and not the computer's A port
The USB-B is the cable's printer-facing end. It is the half of the A-to-B pairing that the printer defines – most printers take the full-size B, and the cable's B end is shaped to that port.
Full-Size B versus mini-B: The Printer-Side Split
| Printer-side connector | Typical on | Cable's device end |
|---|
| Full-size USB-B | Most current and recent printers | The standard USB-B plug |
| USB mini-B | Some older printers, scanners, cameras | The smaller mini-B plug |
| The point | Read the printer's port shape | The device end must match it – B or mini-B |
The split to check is full-size B against mini-B. Most printers use the full-size square B; some older devices use the smaller mini-B. The cable's device end must match the port's shape – a full-B cable will not fit a mini-B port and vice versa.
Why the Printer Side Is B and Not A or C
- The USB-B shape is the historical device-side standard for printers – the port is keyed for it
- It is a data port – the printer receives jobs over it
- Newer computers moving to USB-C-only is what introduces the B-to-C variant on the computer side
- The printer side has stayed B – it is the printer's established port, not the computer's changing one
The printer's USB port has been the full-size B for most of its life; the change has come on the computer side (the move to USB-C). That is why the printer cable's device end is still B, and why the computer-side variant (B to C) is the newer addition.
Per-SKU printer-cable connector variants, length ratings, and data classes are not provided in the knowledge base. The connector shapes, the B-versus-mini-B split, and the A-to-B pairing are the standard reference; confirm the specific cable's device-end connector and rating with the supplier for the printer in question.
Real-World Applications
Reading the printer's port
At the printer's rear, the square beveled port is the full-size USB-B – the standard. A smaller trapezoid-ish port is the mini-B, on older devices. The shape read is the first step in choosing the matching cable.
The standard desktop printer
Most desktop and office printers take the full-size B: the standard A-to-B cable, the B end into the printer, the A end into the computer. The common case, and the default assumption.
The older scanner or printer
An older device with the mini-B port: the cable's device end must be the smaller mini-B. The full-size B will not fit – the mini-B variant is the match for that port shape.
Related reading: The full A-to-B pairing? Read the USB A to B cable guide — blogs/news/usb-a-b-cable
Related reading: Browse USB printer and data cables — collections/usb-cables
Frequently Asked Questions
What is a USB Type B printer cable?
A printer cable whose device (printer) end is the USB Type B connector – the square, beveled plug. It is the printer-side half of the standard USB A to B printer cable; the computer takes the flat USB-A end.
How do I tell USB-B from USB-A?
USB-A is flat and rectangular (the computer's ports). USB-B is squarish with beveled corners (the printer's port). The shape is the identifier – flat is A, square-beveled is B.
Is USB-B the same as USB mini-B?
No – USB-B is the full-size square connector on most printers; USB mini-B is a smaller variant on some older printers, scanners, and cameras. The cable's device end must match the port's size – B or mini-B.
Why do printers use USB-B and not USB-A or USB-C?
The USB-B is the historical device-side standard for printers – the port is keyed for it and carries the print data. The change has come on the computer side (the move to USB-C), not the printer's, which is why the printer end stays B.
Looking for a verified, spec-matched USB printer cable, A-to-B data cable, or connector solution for your project? Contact our engineering and B2B sales team for datasheets, compatibility test reports, and volume pricing. Request a quote or sample.
