Short answer: Charging speed depends on the charger, the device and the cable together. For most phones any decent USB-C cable works. For laptops over 60 W you need a cable rated for 5 A (100 W or 240 W).
USB-C describes the shape of the plug, not what travels through it. Two cables that look identical can differ in how much power they carry and how fast they move data.
Power: 60 W, 100 W and 240 W
With USB Power Delivery, the charger, the device and the cable agree on a power level before charging starts. The cable sets a ceiling:
- Standard cables carry up to 3 amps, which means up to 60 W (20 V × 3 A).
- 5 A cables contain a small chip, called an e-marker, that tells the charger they can handle more: up to 100 W (20 V × 5 A).
- 240 W cables support the newer Extended Power Range, up to 48 V × 5 A, for the most power-hungry laptops.
If any one of the three parts is limited, charging drops to that limit.
Tip: Most phones charge at 45 W or less over standard USB-C, so a 60 W cable is enough. Some brands' faster charging, 65 W and above, only works with their own charger and cable. Buy a 100 W or 240 W cable for a laptop.
Data: why some cables are slow for files
Many USB-C cables, especially the ones that come with phones, only support USB 2.0 data at 480 Mbps. That is fine for charging but slow for copying videos or backing up to an external drive. For fast data, look for USB 3.2 (5 to 20 Gbps), USB4 or Thunderbolt on the packaging.
Why your phone says it is charging slowly
The usual causes, in order: a low-power charger (many older bricks give 5 to 10 W), a damaged or very cheap cable, or a phone that limits charging when it is hot. Try a known-good charger and cable before blaming the phone.
Choosing a cable
- Check what you need to charge. Phone or earbuds: a standard cable is enough. Laptop: check its charger's wattage.
- Match the rating. Up to 60 W: any certified cable. 61 to 100 W: a 5 A / 100 W cable. Over 100 W: a 240 W cable.
- Decide if data speed matters. Only if you move large files or use external drives or monitors.
- Buy a certified cable. Look for USB-IF certification or a reputable brand. Badly made cables can damage ports.
Questions people ask
Q: Can a 100 W cable damage my phone?
A: No. The phone only draws what it can take. A higher-rated cable simply allows more power when a device asks for it.
Q: Is a longer cable slower?
A: For charging, a good cable of 2 metres or less makes little difference. For high-speed data, longer cables often support lower speeds, so check the rating.