That exists. It's called an e-marker and you can buy testers for about $60 that will read it for you. If a cable doesn't have one of those markers then odds are

That exists. It's called an e-marker and you can buy testers for about $60 that will read it for you. If a cable doesn't have one of those markers then odds are it can't handle over 5 amps or USB 2.0 speeds. It is kind of annoying that that functionality isn't built into phones and PCs though. There was some talk about building support into the Linux kernel[1] but it doesn't seem like that went anywhere. [1]: https://people.kernel.org/bleung/now-how-many-usb-c-to-usb-c-cables-are-there-usb4-update-september-12 https://people.kernel.org/bleung/now-how-many-usb-c-to-usb-c...