Difference Between USB-A and USB-C
USB-A is the traditional rectangular connector that only fits one way. USB-C is the newer, smaller, oval connector that is reversible. USB-C supports faster data transfer, higher power delivery, and can carry video signals. USB-C is becoming the universal standard.
Key Takeaways
- USB-A has been the standard USB connector since the 1990s.
- USB-C refers to the connector shape; the speed and features depend on the underlying protocol (USB 2.
- Not all USB-C cables support all features; charging cables may not support high-speed data or video.
Explanation
USB-A has been the standard USB connector since the 1990s. Its rectangular shape with internal plastic insert means it only fits one way. USB-A ports are still common on computers and chargers for backward compatibility with older devices.
USB-C is a newer connector standard introduced in 2014. Its symmetrical oval design allows insertion either way. Beyond convenience, USB-C supports USB 3.1/3.2/4 speeds, USB Power Delivery for high-wattage charging, and alternate modes like DisplayPort and Thunderbolt.
USB-C is increasingly required by regulation in many regions for phones and small electronics. New laptops, tablets, and phones predominantly use USB-C. Many devices are transitioning to USB-C only, though adapters remain available.
Data transfer speeds highlight the generational gap between the two connectors. USB-A maxes out at USB 3.0 speeds of 5 Gbps (gigabits per second), though many USB-A ports still operate at USB 2.0 speeds of just 480 Mbps. USB-C can support USB 3.2 Gen 2x2 at 20 Gbps and USB4 at up to 40 Gbps. For context, transferring a 10 GB video file takes about 16 seconds at USB 3.0 speeds but under 2 seconds over USB4. Thunderbolt 4, which uses the USB-C connector exclusively, pushes throughput to 40 Gbps with plans for 80+ Gbps in future specifications.
Power delivery is another major advantage of USB-C. Standard USB-A ports deliver only 2.5 watts (5V at 0.5A), enough for charging a phone slowly but not much else. USB-C with Power Delivery protocol can deliver up to 240 watts (48V at 5A) under the latest EPR standard, sufficient to power gaming laptops and even some desktop monitors. This is why modern laptops from Apple, Dell, and Lenovo have replaced their proprietary charging ports with USB-C. The EU mandate requiring USB-C on all small electronics by late 2024, which Apple complied with for the iPhone 15, further cements USB-C as the universal connector.
Things to Know
- USB-C refers to the connector shape; the speed and features depend on the underlying protocol (USB 2.0, 3.0, 4, Thunderbolt).
- Not all USB-C cables support all features; charging cables may not support high-speed data or video.
- USB-A to USB-C cables allow connecting newer devices to older computers and chargers.
- Some cheap USB-C cables omit the e-marker chip needed for high-wattage power delivery, limiting them to 60W despite having a USB-C plug on both ends.