USB Reference
USB Standards
USB standards define how data speeds and capabilities evolved from USB 1.x through USB4 and how the major generations compare.
Comparison · USB 3.x naming · Articles
Related: USB Connectors · USB Charging · USB Adapters
USB standards comparison
Compare each USB generation by its supported data rates, connector requirements, and current status without confusing the standard with the connector shape.
| Standard | Defined data rates | Maximum data rate | Connector requirement | Current position |
|---|---|---|---|---|
| USB 1.x | 1.5 Mbps Low-Speed; 12 Mbps Full-Speed | 12 Mbps | Original Standard-A and Standard-B era | Legacy |
| USB 2.0 | 1.5 Mbps; 12 Mbps; 480 Mbps High-Speed | 480 Mbps | Used across USB-A, USB-B, Mini USB, Micro USB, and USB-C implementations | Still widely supported |
| USB 3.0 | 5 Gbps SuperSpeed | 5 Gbps | Introduced SuperSpeed connector forms; later absorbed into USB 3.2 naming | Historical revision |
| USB 3.1 | 5 Gbps and 10 Gbps | 10 Gbps | Supported by suitable SuperSpeed and USB-C implementations | Historical revision |
| USB 3.2 | 5 Gbps, 10 Gbps, and 20 Gbps | 20 Gbps | 20 Gbps two-lane operation requires USB-C | Current USB 3.x family |
| USB4 | 20 Gbps and 40 Gbps in the original generation | 40 Gbps | USB-C required | Current family |
| USB4 Version 2.0 | 80 Gbps symmetric; optional 120/40 Gbps asymmetric operation | 80 Gbps symmetric; up to 120 Gbps in one direction | USB-C required; higher rates require suitable cables and implementations | Current USB4 specification generation |
Sources: USB-IF USB 2.0 Specification, USB-IF USB 3.2 Revision 1.1 Base Specification, USB-IF USB4 overview, USB-IF USB4 Specification v2.0, USB-IF USB Data Performance Language Usage Guidelines, and USB-IF USB Type-C Cable and Connector Specification.
USB 3.x naming history
USB 3.x names changed as newer revisions absorbed earlier specifications, so older labels still appear on products even when the underlying speed is the same.
| USB revision | Data rates | Later specification names | Branding / current name |
|---|---|---|---|
| USB 3.0 | 5 Gbps | USB 3.1 Gen 1 → USB 3.2 Gen 1 / Gen 1x1 | SuperSpeed USB → USB 5Gbps |
| USB 3.1 | 5 Gbps and 10 Gbps | USB 3.2 Gen 1 / Gen 1x1 and Gen 2 / Gen 2x1 | SuperSpeed USB / SuperSpeed USB 10Gbps → USB 5Gbps / USB 10Gbps |
| USB 3.2 | 5 Gbps, 10 Gbps, and 20 Gbps | Gen 1 / Gen 1x1, Gen 2 / Gen 2x1, and Gen 2x2 | SuperSpeed USB / SuperSpeed USB 10Gbps / SuperSpeed USB 20Gbps → USB 5Gbps / USB 10Gbps / USB 20Gbps |
Sources: USB-IF USB 3.1 language usage guidelines, USB-IF USB Data Performance Language Usage Guidelines, and USB-IF USB 3.2 Revision 1.1 Base Specification.
USB standards articles
Read practical guides about USB generation compatibility, backward compatibility, performance, expansion hardware, and devices that use different USB standards.
