CableCheck
Three taps to the one marking to look for on the cable in your drawer.
Three taps to the one marking to look for on the cable in your drawer.
Every USB-C cable uses the same oval plug, so you cannot tell by looking whether the one in your hand does 100W charging, 4K video, or fast file transfer. Two cables that seem identical can behave completely differently: one carries full laptop power and a 4K display, the next only trickle-charges a phone. The quiz above asks what you are plugging in and what you need, then gives you the one marking to check on the plug, so you can pick the right cable in about ten seconds.
Look for a lightning-bolt icon or a "5A" marking printed near the plug or on the cable jacket. Cables rated for 100W (and the newer 240W) include an e-marker chip and are labelled for 5A. An unmarked cable usually caps out around 60W, which is fine for a phone but short for most laptops. If there is no marking at all, treat it as a 60W cable.
Check the plug for a small Thunderbolt icon: a lightning bolt inside a squared outline, often with a 3 or 4 next to it. A Thunderbolt cable also handles 10Gbps or 20Gbps transfer and 4K (or higher) video. No Thunderbolt icon and no "SS10" or "SS20" marking means the cable is likely limited to slow USB 2.0 speeds and may carry no video signal at all.
Yes. The quiz at the top of this page is exactly that. Instead of reading a spec chart, you answer three questions and get one specific marking to look for on the cable you already own. It runs entirely in your browser, with no login and nothing to install.
USB-C is a connector shape, not a single standard. The same plug can hide USB 2.0, USB 3.2, USB4, Thunderbolt, DisplayPort Alt Mode, and several power tiers. Manufacturers rarely print the full capability on the cable, so the only reliable clues are the small markings (5A, DP, SS10, a Thunderbolt icon) near the plug.
5A signals a high-power cable good for 100W charging. DP or a small monitor icon means the cable carries a DisplayPort video signal for an external display. SS10 or SS20 (SuperSpeed) marks 10Gbps or 20Gbps data transfer. A plain cable with none of these is a basic charge-and-sync cable.
View the source on GitHub