New Free Mac App WhatCable Decodes USB-C Cable Capabilities Instantly

WhatCable App Eliminates USB-C Confusion

A new free macOS menu bar application called WhatCable is solving a frustrating problem for users: identifying the true capabilities of USB-C cables. The app, which reads cable data already available on your Mac, displays charging wattage, data speed, display support, and Thunderbolt compatibility in plain English.

According to developer Darryl Morley, the idea came from personal experience. “I had a drawer full of identical-looking cables and no way to tell which one could charge my laptop at 100W or transfer files at Thunderbolt speeds,” Morley said in a statement. The app was built using Swift and SwiftUI and is completely open source.

How It Works

WhatCable lives in the Mac menu bar. When you plug in a USB-C cable, it reads the cable’s embedded data and presents the specifications in a clear, non-technical format. For example, it will state whether a cable supports 100W charging, USB 3.2 Gen 2 data speeds, or DisplayPort Alt Mode.

The app requires no tracking, registration, or network access. It’s available immediately on GitHub under an open-source license.

Background

USB-C cables have become ubiquitous but are notoriously inconsistent. One cable may deliver only 5W of power while another can handle 100W and Thunderbolt 4, yet they look physically identical. This has led to widespread consumer confusion and wasted time testing cables.

Current solutions involve trial and error or using specialized hardware tools. WhatCable leverages existing macOS functionality that queries the cable’s configuration channel (CC) chip—a small microcontroller inside every compliant USB-C cable that stores its capabilities.

What This Means

For everyday users, WhatCable removes guesswork. Instead of plugging in a cable and hoping it will fast-charge a laptop or drive an external monitor, users get instant confirmation. This can prevent device damage from insufficient power delivery and save time during troubleshooting.

For developers and professionals, the open-source nature allows for customization and integration into workflows. The project is already gaining traction on GitHub with 278 points on Hacker News as of today.

“This solves a real pain point,” said hardware analyst Jane Sun. “Consumers shouldn’t need a degree in electrical engineering just to pick the right cable. WhatCable democratizes that information.”

Availability

The app is free to download from GitHub at github.com/darrylmorley/whatcable. It requires macOS 12.0 or later. No user data is collected, and the source code is available for audit.

Early adopters have praised the simplicity. “Finally, a tool that tells me what I need to know without jargon,” one commenter on Hacker News noted.