# item.guide
Side-by-Side Comparison USB

Micro-USB vs. USB4

Comparing 2 standards across 8 specifications. 8 key differences identified.

Comparing:
Micro-USB
USB4

Micro-USB (Micro-B) was the dominant charging and data connector on non-Apple smartphones and small electronics from the late 2000s through the mid-2010s. Its USB 3.0 variant added a second, wider tab beside the standard 5-pin plug for extra SuperSpeed pins -- a design most phone makers skipped, keeping plain USB 2.0 Micro-B nearly universal in practice.

View full Micro-USB spec sheet →

USB4, released August 2019, is built on Intel's Thunderbolt 3 protocol, donated to USB-IF as the new foundation -- up to 40 Gbit/s, a mandatory USB-C connector, and tunneling that lets a single port carry USB, DisplayPort, and PCIe traffic at once. Thunderbolt 3 compatibility is required; Thunderbolt 4 compatibility is optional for device makers.

View full USB4 spec sheet →

Specification Comparison Table

8 Parameters
Parameter / Spec
Pin Count
5 (USB 2.0) or 10 (USB 3.0, wider stepped shape)
Standard Base Dimensions
~6.85 x 1.8 mm
Reversible
No
Status
Largely superseded by USB-C
Released
August 2019
Max Bandwidth / Data Rate
Up to 40 (Gen 3x2) or 20 (Gen 3x1) Gbit/s
Connector Required
USB-C only
Protocol Foundation
Intel Thunderbolt 3 (donated to USB-IF)