A USB-C cable supports both fast charging and data transfer only if it is fully wired, carries an e-marker chip for high power, and meets USB 3.1 or higher for data — check the cable markings, packaging labels, or test it with a tool like USBDeview.
- Cable is rated USB 3.1 Gen 2 or higher (10 Gbps data)
- Cable supports USB Power Delivery 3.0 (up to 100W or more)
- Cable has an e-marker chip (required above 60W)
- Cable is fully wired, not charge-only
- Cable is charge-only with no data pins wired
- Cable is USB 2.0 spec (480 Mbps max, even if it charges fast)
- Cable lacks an e-marker and is used above 60W
- Unmarked or thin cables with no certification label
What to Look for on the Cable or Packaging
The fastest way to check is to read the cable itself or its box. Reputable cables print the USB version and wattage rating directly on the cable body or packaging. Look for these key labels:
- USB 3.1 / 3.2 Gen 2 — confirms 10 Gbps data transfer speed
- USB4 or Thunderbolt 4 — confirms up to 40 Gbps and 240W charging
- PD 3.0 or 100W / 240W — confirms USB Power Delivery fast charging
- E-Marked — confirms the cable has a chip that allows safe high-power delivery above 60W
If the cable has no markings at all, treat it as a USB 2.0 charge-only cable until proven otherwise. The USB-IF Power Delivery specification defines exactly what each rating means and what hardware is required to meet it.
How to Test Your Cable
Labels can be wrong or missing. Use software to confirm what your cable is actually doing.
- USBDeview (Windows) — shows the USB version your cable is negotiating, confirming whether it is running at USB 2.0, 3.1, or higher speeds
- File transfer test — copy a large file and time it; USB 2.0 tops out near 40 MB/s real-world, while USB 3.1 Gen 2 can exceed 800 MB/s
- USB-C power meter — a small inline meter shows actual wattage; if a 100W charger only delivers 18W, the cable lacks PD or an e-marker
Common Setup Comparison
| Setup | Works? | Need | Note |
|---|---|---|---|
| Fast charge + 10 Gbps data | Yes | USB 3.1 + PD 3.0 cable | Must be fully wired with e-marker |
| Fast charge only | Yes | PD cable, any USB version | Data may still be USB 2.0 speed |
| Data only, no fast charge | Yes | USB 3.1+ cable | Charging will be slow or absent |
| Unmarked cheap cable | No | Certified replacement | Likely charge-only, USB 2.0 |
USB-C cables can also carry video signals — see our guide on whether USB-C supports video output for more on that use case. If you are connecting to a display, check our article on how USB-C connects to HDMI to make sure your cable handles all signals correctly.
Bottom line: A USB-C cable that supports both usb-c cable fast charging and data transfer will be clearly marked with a USB 3.1 or higher version, a PD wattage rating, and an e-marker for cables above 60W — if yours has none of these, run a quick file transfer and power meter test before relying on it.