USB-A vs USB-C: What’s the Difference (And Which Should You Use)?

You’re staring at a drawer full of cables, trying to figure out which one actually works with your new phone. Sound familiar? The shift from USB-A to USB-C has left a lot of people confused about what they actually need, and whether all those old cables are now useless.

Here’s the truth: understanding the difference between USB-A and USB-C isn’t complicated once you know what you’re looking at. And no, you probably don’t need to throw everything away and start fresh.

What’s the Difference Between USB-A and USB-C?

The main difference between USB-A and USB-C is the connector design and what it enables.

USB-A is the larger, traditional rectangular connector you’ve used for decades. It’s designed mainly for basic charging and data transfer. You know the one—it only fits in one way, and you never get it right on the first try.

USB-C is the smaller, oval-shaped reversible connector found on modern devices. It supports higher power delivery, faster data transfer speeds, and additional functions like video output.

Here’s where it gets confusing for most people: the letter (A or C) refers to the connector shape, while the number (2.0, 3.0, 3.2, USB4) refers to the speed standard. These are entirely separate things.

A USB-C port can run at slow USB 2.0 speeds. A USB-A port can support fast USB 3.2 speeds. The connector doesn’t guarantee the speed—you need to check both.

USB-A vs USB-C: What are the Data Transfer Speeds Differences?

Both USB-A and USB-C can support multiple speed standards. The difference is that USB-C unlocks the fastest speeds available today, while USB-A tops out earlier.

USB-A ports typically support:

• USB 2.0: 480 Mbps
• USB 3.0/3.1 Gen 1: 5 Gbps
• USB 3.1 Gen 2: 10 Gbps

USB-C ports can support:

• USB 2.0: 480 Mbps (yes, some cheap cables are this slow)
• USB 3.2 Gen 2: 10 Gbps
• USB 3.2 Gen 2x2: 20 Gbps
• USB4: up to 40 Gbps
• USB4 Version 2.0: up to 80 Gbps

What does this mean in practice? Transferring a 10GB video file at USB 2.0 speeds takes around 3 minutes. At USB 3.2 Gen 2 (10 Gbps), it takes about 10 seconds.

The catch? Your transfer speed is only as fast as the slowest link in the chain. A USB4 drive plugged into a USB 2.0 port, or connected with a cheap cable, will crawl along at 480 Mbps regardless of what the drive can actually do.

Source: Unsplash

USB-A vs USB-C: What are the Charging Speed Differences?

This is where USB-C really pulls ahead.

USB-A charging:

• Standard: 5W (5V/1A)
• Quick Charge compatible: up to 18W
• Maximum with BC 1.2: ~7.5W

USB-C charging:

• Standard USB-C: up to 15W (without USB PD, depending on device and cable)
• USB Power Delivery: up to 100W (enough for most laptops)
• USB PD 3.1: up to 240W

What this means in practice: A USB-A to Lightning cable charges an iPhone to around 30% in 30 minutes. A USB-C to USB-C cable with Power Delivery gets the same phone to 50%+ in the same time.

The real game-changer is USB Power Delivery. It can supply up to 20 times more power than a standard USB-A port, which is why you can now charge laptops, tablets, and phones from the same USB-C charger. Try doing that with USB-A.

Can You Use Adapters Between USB-A and USB-C?

Yes, but with important limitations.

USB-A to USB-C cables and adapters:

• Work for basic charging and data transfer
• Speed capped at the USB-A port’s capability
• No access to USB-C exclusive features (Power Delivery, Alt Mode, video output)

Here’s the key point: an adapter creates a physical connection but can’t unlock capabilities the port doesn’t have. Your USB-C phone plugged into a USB-A port via an adapter won’t fast-charge—it’s limited to whatever the USB-A port can deliver.

If you need the full benefits of USB-C (fast charging, high-speed data, video output), both ends of the connection need to be USB-C.

Why Is Everything Switching to USB-C?

The short answer: regulation and practicality.

The EU mandate: As of December 28, 2024, all phones, tablets, cameras, headphones, and most portable electronics sold in the EU must use USB-C for charging. Laptops follow in April 2026. This pushed even Apple to switch from Lightning to USB-C with the iPhone 15 in 2023.

Benefits of driving the switch:

• One cable for (almost) everything
• Faster charging across devices
• Reduced e-waste (estimated 11,000 tonnes annually in the EU)
• Reversible connector (finally)

The EU estimates this will save consumers around €250 million per year by eliminating the need for device-specific chargers. Whether you’re in the EU or not, the global supply chain is shifting—USB-C is becoming the universal standard.

Should You Replace All Your USB-A Cables and Chargers?

Not necessarily. Here’s a practical breakdown.

Keep USB-A if:

• Your devices still use USB-A ports
• You’re charging low-power devices (keyboards, mice, earbuds)
• You need maximum compatibility with older equipment

Switch to USB-C when:

• Buying new phones, tablets, or laptops
• You want faster charging
• You’re tired of carrying multiple cable types
• You’re buying new chargers or power banks anyway

Smart transition strategy: Buy dual-port chargers and power banks with both USB-A and USB-C outputs. This bridges the gap while you gradually move to USB-C, without making your existing cables obsolete overnight.

Making the Transition Simple

USB-C is the future, but the transition doesn’t have to be painful. The key is understanding that connector shape and speed standard are separate things, and choosing cables and chargers that match what your devices actually need.

For most people, dual-port chargers and power banks with both USB-A and USB-C ports offer the best of both worlds. You get USB-C fast charging for newer devices while keeping compatibility with older gear.

UGREEN’s range of dual-port chargers, USB-C cables, and adapters is designed precisely for this transition, giving you flexibility without forcing you to replace everything at once.