Gadget tells you what that mystery USB-C cable can do

I have a drawer full of USB-C cables. Some of them carry display. Some of them carry data. Some go fast. Some go slow. Some will charge a pair of finicky Sony headphones. One cost $30, does it all, and has a lovely braided fabric wrap. One was $3 from a box on the checkout at Staples and is hot pink. Some have tiny text on them suggesting what they can do, but most don't, and I would need something like petl's USB cable testers to figure it out without trial and error. From the Github page:

The amount of possible USB C cable combinations is endless. If you use the wrong cable, data transmission may be slower than possible or certain devices may not work at all. In the USB C standard, the cable plays an important role and has to advertise itself as such. All of them need to have certain pins connected, some need to be grounded, some need to have resistors attached.

USB 2.0/1.1
USB Power Delivery
USB 3.0/3.1/3.2
Alternate Mode
Debug Accessory Mode
Audio Adapter Accessory Mode

It's just shy of 30 Euros, and there's a version for the other common mystery cable, HDMI. There's a Kickstarter underway for a fancy model with a screen that tells you straight up how fast, how good and how juicy the cable is, for 70 Euros.

If you're looking for one that does ethernet or fiber, they're common as muck at the usual places, but you'll need a pricey one from Klein or whoever if you want to know speeds: look for "certifiers" not "testers".