USB Standards and Connector Types | Type-A vs B vs C, USB 1.1 to USB4

Compare USB versions 1.1, 2.0, 3.0, 3.1, 3.2, and USB4 by year, connector type, max transfer speed, and key features. A free reference that answers "what are the different types of USB?" with a search filter.

Last updated: 2026-09-21

USB Standards Comparison Table

Standard	Connector	Year	Max Transfer Speed	Key Feature	Current Status
USB 1.1	Type-A / Type-B	1998	12 Mbps	The first widely adopted USB standard, used for connecting low-speed devices such as mice and keyboards.	Has largely disappeared from today's consumer devices, remaining only for compatibility with legacy hardware.
USB 2.0	Type-A / Type-B / Mini-B / Micro-B	2000	480 Mbps	Marketed as "Hi-Speed USB," it became the long-standing standard for a wide range of peripherals such as USB flash drives, external hard drives, and printers.	Slow by today's standards, but still actively used for inexpensive mice, keyboards, and charge-only cables.
USB 3.0	Type-A / Micro-B / Type-C	2008	5 Gbps	Often identified by blue-colored connectors and cables, this was the first SuperSpeed standard, offering roughly 10 times the theoretical speed of USB 2.0.	Later renamed USB 3.1 Gen1 and then USB 3.2 Gen1 — the starting point of the naming confusion around USB 3.x.
USB 3.1 Gen2	Type-C	2013	10 Gbps	Known as SuperSpeed+, it doubles USB 3.0's speed to 10 Gbps, and is mainly adopted with USB-C connectors.	Later also called USB 3.2 Gen2. Commonly used for connecting fast external storage such as external SSDs.
USB 3.2 Gen2x2	Type-C	2017	20 Gbps	Reaches a theoretical 20 Gbps by using two data lanes simultaneously — a standard supported only over USB-C connectors.	Few devices and cables support it so far, and adoption remains limited as the industry moves toward USB4 instead.
USB4	Type-C	2019	40 Gbps	Standardized based on Thunderbolt 3 technology, USB-C only, supporting up to 40 Gbps, DisplayPort Alt Mode, and up to 100W of power delivery.	Adoption is growing, especially among Macs and high-performance laptops, as a unified connectivity standard for peripherals.
USB4 2.0	Type-C	2022	80 Gbps	A further enhancement of USB4 using a new physical layer, reaching a theoretical 80 Gbps (or 120 Gbps in one direction only) — the latest standard.	Compatible products have only just begun appearing since 2024 — widespread adoption is still ahead.

What Is the USB Standards Comparison Table?

USB has grown through seven generations, from USB 1.1 all the way to USB4 2.0. Along the way, the very same underlying standard has been renamed more than once — most notably "USB 3.0" becoming "USB 3.1 Gen1" and then "USB 3.2 Gen1" — which makes it genuinely hard to judge real-world performance from packaging or spec sheets alone. This tool brings together the year each standard was finalized, its connector shape, maximum transfer speed, key features, and current relevance into a single table, so you can filter and compare them side by side.

The transfer speeds listed here are the theoretical maximums defined by each standard. You'll only see that speed in practice when the cable, the device, and the port all support the same generation of the standard. If even one of the three is an older standard, your actual throughput gets capped at whichever link is the weakest.

How to Use the USB Standards Table

Scan the full comparison table Standard name, connector shape, year finalized, max transfer speed, key feature, and current status are all laid out in one table.
Narrow it down with the filter Type a keyword like "Type-C" or "Gen2" into the box at the top to show only the matching rows.
Check the "Current Status" column for real-world relevance This tells you at a glance whether a standard is legacy or still mainstream in today's products.
Cross-check against your own devices, cables, and ports Before buying anything, confirm all three pieces support the standard you actually need for your target speed.

Tips for getting more out of it

Even if a cable itself supports USB4, you won't get that speed unless the devices on both ends also support USB4. Check the cable, the devices, and the ports all together.
A USB-C connector shape alone doesn't tell you the internal standard (USB 2.0, 3.2, or 4) that a given cable supports, so you can't judge speed from the connector shape alone.
Fast charging (USB Power Delivery) requires a USB-C connector plus a matching combination of cable, charger, and device that all support it.
Ports for USB 3.0 and later are often colored blue inside, which lets you visually distinguish them from older USB 2.0 ports at a glance.
To get the full speed out of fast external storage like an SSD, choose a cable and port that support USB 3.2 Gen2 or later.

When This Comes In Handy

Before buying an external SSD or dock

Find out ahead of time which USB generation you need to run fast storage or a docking station at its full rated speed.

Checking compatibility between old gear and a new PC

See how far backward compatibility extends — whether a USB 2.0-era peripheral will still work on a modern USB4 port.

Choosing a fast-charging cable

The feature column for each standard tells you whether USB PD is supported and roughly what wattage to expect.

Decoding a laptop's spec sheet

Look up exactly what confusing labels like "USB4" or "USB 3.2 Gen2x2" actually mean, right on the spot.

Glossary

USB-IF: The industry group (USB Implementers Forum) responsible for developing and certifying USB standards. It's also the body behind the various standard-name changes over the years.
SuperSpeed: An umbrella term for the high-speed USB 3.0 family of standards (5 Gbps and above). Compatible cables and ports are often marked or colored blue for easy identification.
Alternate Mode (Alt Mode): A mechanism that lets a single USB-C cable carry other protocols — such as DisplayPort video — alongside standard USB data signals at the same time.
USB PD (Power Delivery): A standard that enables high-wattage charging over USB, delivering up to 240W. It's commonly used for fast-charging laptops and other power-hungry devices.
Thunderbolt: A high-speed interface standard championed by Intel and Apple. USB4 was standardized based on Thunderbolt 3 technology, and the two remain closely related.
Backward compatibility: The ability of a newer standard's ports or devices to accept cables and devices built to an older standard — though the connection speed is limited to the older one.

Frequently Asked Questions

USB 3.0 was later renamed USB 3.1 Gen1 and then USB 3.2 Gen1 — essentially the same 5 Gbps standard under different names. USB 3.1 Gen2 is a newer, higher-speed standard supporting 10 Gbps, and the renaming history is what makes the difference confusing.

USB4 was standardized based on Thunderbolt 3 technology and shares the same connector shape and some features, but Thunderbolt 4 is Intel's own certification standard that layers stricter mandatory requirements on top of USB4, such as a guaranteed minimum of 40 Gbps and mandatory external display support.

No. Even with the same USB-C connector, the internal standard supported (anywhere from USB 2.0 to USB4) and the power delivery capacity vary by cable, and some inexpensive cables are charge-only and don't support high-speed data transfer.

Most USB4 ports are backward compatible, so you can connect a USB 2.0 device using a Type-A-to-Type-C adapter, but the transfer speed will be limited to USB 2.0's 480 Mbps.

Since 2024, the USB PD standard supports up to 240W, which is used for fast-charging laptops, but the power adapter, cable, and device all need to support that wattage for it to work.

Side Note — Why Is USB Naming So Confusing?

USB standard names have a history of repeatedly changing since they were first introduced. "USB 3.0," which debuted in 2008, was renamed "USB 3.1 Gen1" in a 2013 naming reorganization by the USB-IF (the industry group that develops USB standards), and then renamed again to "USB 3.2 Gen1" in 2017. The underlying transfer speed (5 Gbps) never changed, yet the name changed three times, causing widespread confusion among consumers about which standard was actually faster. Learning from this, the USB-IF has switched to simple generational names — "USB4" and "USB4 2.0" — for everything after USB4.

The real significance of the USB-C connector isn't just its smaller size — it's the reversible design that lets you plug it in either way up, and a mechanism called "Alternate Mode" that lets a single cable carry multiple protocols at once. Inside a USB-C cable, USB data signals, DisplayPort video signals, high-speed Thunderbolt data, and even high-wattage USB Power Delivery charging can all be carried simultaneously, letting one cable act like a dock — powering a laptop, driving an external display, and transferring peripheral data all at the same time.

With USB4 2.0 reaching a theoretical 80 Gbps, USB has largely caught up with the performance of Thunderbolt, a standard originally championed by rivals Apple and Intel. In fact, USB4 itself was standardized based on Thunderbolt 3 technology, and the technical gap between the two keeps narrowing each year. Going forward, the physical connector shape (USB-C) is likely to stay the same while the underlying protocol keeps getting updated in software, making it more important for consumers to check the supported standard of their cables and devices rather than just the connector shape.

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