Decoding USB Standards (2026): USB 1.x, 2.0, USB 3 (5/10/20Gbps), USB4 (40/80Gbps) & Thunderbolt - Explained

If USB naming feels like alphabet soup, you’re not alone. The USB Implementers Forum (USB-IF), a non-profit organization that manages USB technology standards, has revised specs and marketing names multiple times, including retroactive renames, so the same port or speed may appear under different labels depending on the era. To cut through the noise, we’ll use the current plain-language “USB [data rate]” naming (e.g., USB 5Gbps, USB 10Gbps, USB 20Gbps), then map those to legacy terms you’ll still see in the wild.

Quick note on terminology

Connectors (like USB Type-C, USB Standard-A/B) describe the plug shape. Protocols/standards (like USB 10Gbps or USB 40Gbps) describe capabilities such as speed and features. USB 3 introduced multiple connector updates (including USB Type-C) while remaining backward-compatible in many cases.

A brief timeline of consumer USB

USB 1.0/1.1 (Basic-Speed in this guide)

• Introduced 1996/1998; data rates of 1.5Mb/s (Low-Speed) and 12Mb/s (Full-Speed). Common on early mice, keyboards, and printers.

USB 2.0 (High-Speed)

• Launched in 2000; jumps from 12Mb/s to 480Mb/s and adds Mini/Micro connectors widely used on early mobile devices.

USB 3 (USB 5/10/20Gbps)

• 2008: SuperSpeed (5Gbps) using the USB Standard-A connector.
• 2013: SuperSpeed+ (10Gbps) using the USB Standard-A connector and introducing the USB Type-C connector.
• 2017: Renamed to the “Gen” scheme (e.g., USB 3.2 Gen 1x1 = 5Gbps; USB 3.2 Gen 2x1 = 10Gbps; USB 3.2 Gen 2x2 = 20Gbps), which you’ll still see on product pages. Today’s marketing simplifies this to USB 5Gbps / 10Gbps / 20Gbps, and uses the USB Standard-A or Type-C for 5Gbps and 10Gbps, and Type-C exclusively for 20Gbps.

Cable length & power (USB 3 era):

• Typical passive cable guidance: up to 2m/6.6ft for 5Gbps; up to 1m/3.3ft for 10/20Gbps.
• USB Standard-A data ports can supply 4.5W (0.9A at 5V), with optional Battery Charging (BC 1.2) up to 7.5W.
• USB Type-C data ports start at 7.5W and - when USB Power Delivery is supported - can negotiate much higher power output (up to 240W however most ports on computers are limited to 15W for downstream devices)

Common use cases: high-bandwidth peripherals like external SSDs/HDDs, 1080p60+ webcams, docks, and graphics adapters.

USB4 (USB 40/80Gbps)

Launched in 2019 and requires USB Type-C. Unlike earlier versions, USB4 can tunnel multiple data types (USB, DisplayPort video, and optionally PCIe), enabling flexible performance sharing across devices like docks, storage, and displays. USB4 uses clearer speed branding (USB 40Gbps, USB 80Gbps) alongside spec labels like USB4 Gen 3x2 and USB4 Gen 4x2. Passive USB4 40Gbps cables are commonly limited to 0.8m/2.6ft; Power Delivery can still negotiate up to 240W on capable ports.

Thunderbolt vs. USB - how they relate

• Thunderbolt 1/2 (mini-DisplayPort connector) were separate from USB.
• Thunderbolt 3 moved to USB Type-C and can connect USB devices (up to USB 10Gbps) to a Thunderbolt 3 host, but Thunderbolt 3 devices generally won’t work in a non-Thunderbolt USB-only port.
• USB4 was heavily influenced by Thunderbolt 3, and Thunderbolt 3 devices interoperate with USB4 hosts.
• Thunderbolt 4 aligns closely with USB4 and standardizes a robust feature set; Thunderbolt 5 pushes available bandwidth to 80Gbps while retaining strong backward compatibility.

Rule of thumb: Thunderbolt 3 hosts typically handle USB devices up to USB 10Gbps; Thunderbolt 4 and Thunderbolt 5 hosts can handle USB4 devices as well.  USB4 hosts can support Thunderbolt 3 and Thunderbolt 4 devices.

The “cheat sheet” you can screenshot

• If your laptop supports Thunderbolt, a Thunderbolt dock offers the most headroom for multi-display and high-throughput workflows. For broad host compatibility across fleets, USB 3.x/DisplayLink-based solutions are often the safest baseline.
• DisplayLink carries video over USB (USB-A/C) and is great for productivity (including extending multiple monitors on Macs that natively allow only one). While native GPU paths (Alt Mode/Thunderbolt) are preferred for graphics-intensive work.
• Power Delivery: Match dock power to host needs - 60W works for many ultrabooks; 85-100W for performance laptops; higher EPR (140-240W) accommodates the latest and most demanding desktop replacement and workstation notebook computers.

Wrapping up: why the renames matter

The USB-IF’s newer, speed-first marketing names (USB [data rate]) simplify compatibility shopping for USB hosts and devices. Knowing the translation between old and new labels helps you pick the right cables, ports, and docks without guesswork.