USB-PD (USB Power Delivery) is the protocol that lets a USB-C port negotiate voltage and current instead of staying at a phone-charger trickle. The charger, cable, and device exchange a short capability list, then pick a profile both sides can do. A useful picture: USB-C is the plug shape, USB-PD is the conversation about how much power that plug is allowed to carry.

How it works

All three parts have to agree: brick, cable, and laptop (or phone). A 100W GaN charger cannot push 100W through a thin phone cord. As the cable guide puts it: "Above 60W the cable needs an e-Marker chip that advertises 5A." Without that chip, Power Delivery quietly caps closer to 60W even when the brick and the laptop would go higher.

Common PD profiles sit at 5V, 9V, 15V, and 20V. 100W is 20V at 5A. Many multi-port bricks advertise a total (100W or 120W) that is shared. One laptop on the first USB-C port can still see 100W. Two laptops at once will split it.

When it matters

It matters the moment you charge a USB-C laptop, or you want a phone to charge at full advertised speed. A random "fast charging" cable with no watt figure is a 60W-or-less bet. Video and high-speed data are a separate spec. Most bargain 100W cables are charge-only with USB 2.0 data.

If you only charge a phone overnight, USB-PD still works, you just do not need the 5A e-Marked cord.

These are live catalog items already used for 100W charging on the site.

The Anker 100W 6 ft 2-pack is the default e-Marked cord: 20V/5A, nylon braid, no video. View on Amazon when you need a known 100W pair for desk and bag.

The Anker 737 (GaNPrime 120W) can put 100W on a single USB-C port and share 120W across two USB-C ports plus USB-A.

The UGREEN Nexode 100W is the smaller four-port brick (3x USB-C + USB-A). One port can still do 100W; two ports typically split around 65W + 30W.

For e-Marked lengths, data-vs-charge cables, and the 100W shopping bar, read Best USB-C Cables Rated for 100W Charging.