USB-A
The classic rectangle. Tops out at 10 Gbps and can't do USB PD fast charging.
Drawn by CableBin to scale from nominal dimensions. Gold = contacts.
Facts
- Size
- 12.0 × 4.5 mm
- Contacts
- 4 (USB 2.0); 9 (USB 3)
- Reversible
- No
- Introduced
- 1996
- Also called
- USB Type-A, standard-A
The rectangular USB-A port is still on most computers, chargers and cars. USB 3 versions add five contacts at the back of the port, behind the original four, and are often coloured blue (teal or red on some boards for 10 Gbps or always-on charging, though colours aren't standardised).
USB-A can't carry USB PD or video, and it tops out at USB 3.2 Gen 2 (10 Gbps). A USB-A to USB-C cable is fine for data and modest charging, but it won't fast-charge a laptop.
Standards that use it
USB 2.0
The baseline every USB port still speaks. Fine for keyboards, mice and charging; slow for files.
- data: 480 Mbps
- video: No
- power: 2.5 W (port); more via USB-C/PD
USB 3.2 Gen 1 (5 Gbps)
The original USB 3.0, renamed twice. Ten times USB 2.0, enough for hard drives and most flash drives.
- data: 5 Gbps
- video: No (only via USB-C Alt Mode)
- power: 4.5 W (port)
USB 3.2 Gen 2 (10 Gbps)
Double the speed and much better coding. The sweet spot for portable SSDs.
- data: 10 Gbps
- video: No (only via USB-C Alt Mode)
- power: 4.5 W (port)