WhatCable: Your Mac's USB-C Cable Inspector in the Menu Bar

USB-C cables can be confusing—two identical-looking cables might offer drastically different charging speeds, data transfer rates, or display support. Enter WhatCable, a tiny menu bar app for macOS that reads the cable metadata your Mac already accesses, translating technical identifiers into plain English. This open‑source, free tool lets you instantly know what any USB‑C cable can actually do. Below, we answer the most common questions about WhatCable.

Why do I need a USB‑C cable inspector app?

With USB‑C, a single physical connector can carry everything from slow 5 W charging to 100 W Power Delivery and Thunderbolt 4. But cables look identical, making it impossible to tell their capabilities by sight. WhatCable eliminates guesswork: plug in any cable and see exactly what it supports—charging wattage, data speed, display output, Thunderbolt generation, and more. No more fumbling through drawers trying to remember which cable does what.

How does WhatCable work?

The app sits unobtrusively in your Mac’s menu bar. When you plug in a USB‑C cable, WhatCable reads the cable descriptor data that macOS already obtains from the cable itself. It then decodes the raw information (typically vendor, protocol versions, and power profiles) and presents it in a clear, readable format. Because it relies on system‑level data, no external hardware or driver installation is required—just download, launch, and use.

What information does WhatCable provide?

For each connected USB‑C cable, WhatCable displays:

• Charging wattage – maximum power delivery (e.g., 5 W, 60 W, 100 W)
• Data speed – USB 2.0, USB 3.2 Gen 1/2, Thunderbolt 3/4, etc.
• Display support – whether the cable can drive external monitors and at what resolution
• Thunderbolt generation – if the cable supports Thunderbolt, it shows the version
• Other attributes – such as e‑marker presence, vendor name, and protocol version

All this is presented in plain English, so you instantly know whether a cable is suitable for fast charging, data transfer, or video output.

Is WhatCable free? Is it open source?

Yes! WhatCable is completely free to download and use, with no hidden charges or subscription fees. It is also open source—the full source code is available on GitHub. This means anyone can inspect, modify, or contribute to the app. Transparency is a core principle: no tracking, no telemetry, and no data collection of any kind. Your privacy is respected.

Does WhatCable collect any personal data or track me?

No. The developer has explicitly stated that WhatCable includes no tracking whatsoever. The app does not log, transmit, or store any information about your cables, your Mac, or your usage patterns. Because it is open source, you can verify this claim by reviewing the code yourself. Your privacy is fully protected.

Which Mac models and macOS versions are supported?

WhatCable is built using Swift and SwiftUI, and it requires macOS 12 (Monterey) or later. It should run on any Mac that supports that version of macOS, including Intel‑based and Apple Silicon Macs. The app’s light weight means it uses negligible system resources, so it won’t slow down your computer. Check the download section for the latest release.

Where can I download WhatCable?

You can find the latest release on the official GitHub repository. Download the .dmg or .app file, drag it to your Applications folder, and launch. Since it is a menu bar app, you will see its icon appear near the clock; click it to inspect any connected USB‑C cable. For updates, keep an eye on the GitHub page or use a package manager if supported.