New macOS Utility Reveals True Capabilities of USB-C Cables
The open-source menu bar application translates technical USB Power Delivery specifications into plain English, helping users diagnose slow charging issues without relying on private APIs.
A new utility for macOS users has been released to address the confusion surrounding USB-C connectivity. The application, named WhatCable, allows users to inspect the specific capabilities of any USB-C cable plugged into their Mac. By displaying information in plain English, the tool clarifies details such as charging speed and data transfer rates, helping users understand why a device might be charging slowly.
The software was developed by darrylmorley and is designed to surface technical data that macOS already exposes via IOKit services but does not present in a user-friendly manner by default. WhatCable acts as a wrapper to decode USB Power Delivery 3.x specifications, converting complex bit-level information into readable insights. This approach ensures that the distinction between a basic USB 2.0 charge-only cable and a high-speed Thunderbolt 4 cable is immediately apparent to the user.
Unlike many system utilities, the application explicitly avoids using private APIs, entitlements, or helper daemons. Instead, it relies solely on public IOKit services to access the necessary hardware information. The developer has signed the app with a Developer ID and notarised it through Apple, ensuring that users will not encounter Gatekeeper warnings upon installation. The source code remains open on GitHub, with specific files highlighted for readability, including ContentView.swift for the user interface and PortSummary.swift for the plain-English logic.
Installation is straightforward, requiring users to download a zip file from the Releases page on the GitHub repository. Once unzipped, the application can be dragged directly to the /Applications folder. The software is available as a universal binary, supporting both Apple Silicon and Intel Macs, making it compatible with a wide range of hardware configurations. The interface includes a refresh function and a toggle to keep the window open, which is particularly useful for taking screenshots or demonstrating capabilities during demos.
The release comes at a time when the physical uniformity of USB-C connectors often masks significant differences in performance. Users frequently struggle to identify whether a cable is capable of the full 240W power and 40 Gbps data transfer rates of Thunderbolt 4 or if it is limited to slower standards. WhatCable aims to resolve this ambiguity by providing a clear, menu bar popover that details the actual performance limits of the connected cable.
While the application is currently available for download, there is no public information regarding current download statistics or community feedback since its release. The developer invites issues and pull requests on the GitHub repository, suggesting an ongoing commitment to maintaining the tool. For now, the utility stands as a practical solution for anyone seeking clarity on the often opaque specifications of their charging and data cables.
