USB-A is the flat, rectangular plug you find on chargers, computers, and flash drives. It's the "host" end that supplies power and data. Micro-USB is the much smaller plug on the device end, used for years on Android phones, Bluetooth speakers, and power banks.
It comes in two shapes, Micro-A and Micro-B, and Micro-B is the one almost everyone owns. Most cables that pair USB and Micro-USB have a USB-A plug on one end and a Micro-B plug on the other. Below, we'll walk through every common connector, then take a closer look at both.
Different Types of USB Connectors
USB has used more than ten plug shapes since 1996. Some are everywhere, and some are already museum pieces. Each one was built for a certain kind of device, from printers to phones to portable hard drives. Here's a quick tour of the connectors you're most likely to find in a drawer.
USB-A
USB-A is the original USB plug. It measures about 12 by 4.5 mm and only fits one way, which explains all that flipping. A USB A type port sits on laptops, desktops, TVs, game consoles, and wall chargers. The white or black USB 2.0 version has four pins and tops out at 480 Mbps. It's still the most common port on Earth, even as USB-C takes over new phones and laptops.
USB-B
USB-B is the square plug with two slanted top corners. You'll find it on printers, scanners, and audio interfaces. The difference between USB-A and USB-B comes down to roles. USB-A sits on the host, which is the computer. USB-B sits on the device being controlled. That shape rule stopped people from plugging two computers together and frying something.
USB-C
USB-C is the small oval plug that works either way up. It has 24 pins and supports USB 3.2, USB4, and Thunderbolt. The fastest cables reach 40 or even 80 Gbps. It also carries up to 240 watts with USB Power Delivery, which is enough for most laptops. It's rated for about 10,000 plug-ins, so it holds up to daily use.
USB Micro-A
Micro-A is the rarest member of the Micro family. It's a small rectangle with no slanted corners, and it was made for USB On-The-Go. That feature let a phone act as a host for a keyboard or a flash drive. The Micro-USB Type-A plug only fits a Micro-AB port, and very few devices ever shipped with one.
USB Micro-B
Micro-B is the slim plug with slanted sides that charged Android phones for most of the 2010s. It has five pins and runs at USB 2.0 speeds of 480 Mbps. The port is rated for 10,000 cycles, but the tiny tabs inside can loosen over time. You'll still see it on budget earbuds, e-readers, and game controllers.
USB Mini-B (5-Pin)
The 5-pin Mini-B is the chunky little plug from older digital cameras and MP3 players. It measures about 7 by 3 mm. The extra fifth pin tells the device which role it should take. Sony PlayStation 3 controllers, Garmin GPS units, and many dash cams still use it today.
USB Mini-B (4-Pin)
The 4-pin Mini-B looks almost the same, but it's missing the ID pin. Kodak, Fujifilm, and a few other camera makers used it in the early 2000s. It isn't a true USB standard, so a normal Mini-B cable may not fit. If an old camera won't connect, count the pins before you buy a replacement cable.
USB 3.0 A
USB 3.0 A keeps the same outside shape as regular USB-A. Look inside and you'll see a blue insert with nine pins instead of four. Those extra pins push speeds up to 5 Gbps, which is ten times faster than USB 2.0. Plug an older cable in and it still works, just at the slower speed.
USB 3.0 B
USB 3.0 B looks like a USB-B plug with a small box stacked on top. That bump holds the five extra pins needed for 5 Gbps speeds. External drives, docking stations, and some fast scanners use it. A USB 2.0 B cable still fits a 3.0 B port, but a 3.0 B cable won't fit an older 2.0 port.
USB 3.0 Micro B
This one looks like a Micro-B plug with a second little plug glued to its side. It was common on portable hard drives from brands like WD and Seagate. The Samsung Galaxy S5 and Note 3 used it as well. A regular Micro-B cable fits the larger half of the port, but you only get USB 2.0 speed.
USB-A to Micro-B
This is the cable most people have in a drawer. The USB-A end goes into a charger or computer, and the Micro-B end goes into the device. It handles charging and data transfers for phones, speakers, power banks, and controllers. A good one uses thicker wires so it charges at the full 2 amps.
USB Mini-B: Mini USB vs Micro USB
Mini-B came first, in 2000. Micro-USB replaced it in 2007 because it was thinner and lasted longer. Mini-B was only rated for about 5,000 plug-ins, while Micro-B doubled that to 10,000. The mini shape also had a short-lived Mini-A version. If you're comparing Mini-USB A vs B, Mini-A was quietly dropped in 2007, so nearly every mini cable you'll find today is Mini-B.
USB-A (Standard-A)
Standard-A is the formal name for the regular USB-A plug. It's been the "computer end" of the cable since USB was launched. There are several USB A types, including USB 2.0, USB 3.0, and USB 3.2 versions. They share the same outside shape and work together. Here's how the plug is built, what it does, and where you'll use it.
Shape and Design: USB A Specs
The plug is a flat metal shell about 12 mm wide and 4.5 mm tall. Inside sits a plastic tongue with gold-colored contacts. USB 2.0 versions use four pins: power, ground, and two data lines. USB 3.x versions add five more pins and usually have a blue tongue.
Some brands use teal for 10 Gbps ports or red for always-on charging ports. The plug only fits one way, so if it won't go in, flip it once instead of forcing it.
Primary Role of USB Type-A Connectors
USB-A is the host side of the connection. It supplies power and controls the data flow, which is why it's on computers, chargers, and hubs instead of on phones. A standard USB 2.0 port gives 500 mA of power, while USB 3.0 gives 900 mA. Dedicated charging ports can push 2.4 amps or more. Plug in a flash drive, and the computer takes charge of reading and writing files.
Common Uses
USB-A ports are still built into almost every computer and charger sold today. You'll spot them on TVs, cars, and game consoles too. Most gear in a home office plugs into one at some point during the day. These are the places where the rectangular plug still does most of its work.
- Flash drives and external hard drives that plug straight into a laptop or desktop.
- Keyboards, mice, webcams, and wireless receivers on home and office computers.
- Wall chargers, car chargers, and power banks that charge phones and earbuds.
- TVs, streaming sticks, and game consoles that read media or power accessories.
- Printers and scanners linked by an A-to-B cable from the computer side.
Micro-USB (Micro-A and Micro-B)
Micro-USB arrived in 2007 as a slimmer, tougher replacement for Mini-USB. It quickly became the standard charging port on Android phones. The European Union even pushed it as a common charger for a while. There are different micro USB types, and each has its own shape and job. Here's how they look and where you'll find them.
Shape and Design
Both Micro plugs are tiny. The micro USB size is about 6.85 by 1.8 mm, which is roughly one-third the height of USB-A. Each has five pins and small spring latches that grip the port. Shape and color are the quick way to tell them apart. Here's a closer look at each version.
Micro-A USB
The Micro-A plug is a flat rectangle with square corners. The spec gave it a white plastic insert so people could spot it. It was meant for phones and tablets acting as hosts through USB On-The-Go. In practice, makers used Micro-B ports with a simple OTG adapter instead. That's why you'll rarely find a Micro-A cable in stores today.
Micro-B
Micro-B has two slanted corners on one long side, which looks like a small trapezoid. Its insert is usually black. It's the plug most people mean when they say "micro USB." The slanted edge stops you from inserting it upside down, though most of us still try twice. When people compare micro USB A and B, Micro-B is the one that actually shipped on billions of devices.
Primary Role of the Micro-USB Port
This port sits on the device side of the cable. Its main jobs are charging and syncing data at USB 2.0 speed. Most ports handle 5 volts at 1 to 2 amps, which is fine for phones, speakers, and earbuds. Some phones used Quick Charge to push 9 or 12 volts. Many devices also support OTG, so a phone can read a flash drive with an adapter.
Common Uses
USB-C has taken over new flagship phones, but Micro-USB hasn't disappeared. Budget gadgets still use it because the parts cost less. A spare micro USB cord is still worth keeping in a travel bag. These are the devices where you're most likely to plug one in.
- Older Android phones and tablets made before about 2018.
- Bluetooth speakers, wireless earbuds, and budget headphones.
- Power banks, e-readers, and portable fans.
- Game controllers for the PlayStation 4 and Xbox One.
- Raspberry Pi 3 boards, Arduino clones, and small hobby electronics.
Stay Connected With the Right USB Cable From TS Cables
USB-A powers and controls the connection, while Micro-USB charges and syncs the device at the other end. Pick the right plug, check the speed, and choose a cable with thick wires. Shop TS Cables for durable USB and data cables built for everyday charging and fast transfers.
FAQs
Can I plug a Micro-B cable into a USB 3.0 Micro-B port?
Yes, a regular Micro-B plug fits the larger half of a USB 3.0 Micro-B port. It works fine, but transfers run at USB 2.0 speed.
Is USB-A faster than Micro-USB?
USB-A can be faster. USB 3.0 A reaches 5 Gbps, while Micro-B tops out at 480 Mbps. Your actual speed depends on the slower end of the cable.
How do I tell Micro-A from Micro-B?
Micro-B has two slanted corners and a black insert. Micro-A is a flat rectangle with square corners and a white insert. Most cables you own are Micro-B.
Why did phones switch from Micro-USB to USB-C?
USB-C is reversible, faster, and carries far more power. It also lasts longer, and new EU rules now require it on most phones sold there.
How long can a USB cable be?
USB 2.0 cables work up to about 5 meters, and USB 3.0 stops near 3 meters. Our cable distance limits guide covers longer runs.
Further Reading
Got a tangle of cables and no idea which does what? The TS Cables blog sorts it out in plain English. These posts answer the next questions most readers ask:
