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macOS menu bar app that tells you, in plain English, what each USB-C cable plugged into your Mac can actually do

5,711 starsSwift

WhatCable, a tiny menu bar app for inspecting USB-C cables

by sleepingNomad·May 1, 2026·566 points·168 comments
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AI Analysis

●●SolidNiche GemCozy

Finally exposes the hidden IOKit cable data macOS already knows but never shows you.

Strengths
  • •Decodes e-marker chips and PDO lists without private APIs or kernel extensions.
  • •Diagnoses charging bottlenecks by comparing cable ratings against charger capabilities.
  • •Universal binary supporting both Apple Silicon and Intel Macs with zero dependencies.
Weaknesses
  • •macOS-only utility limits the audience significantly compared to cross-platform tools.
  • •Solves a hardware visibility problem that ideally the OS manufacturer should fix.
Target Audience

Mac users, hardware engineers, and anyone frustrated by unlabeled USB-C cables.

Similar To

System Information.app · Cable Matters testers

Post Description

USB-C cables can be a mess. One cable charges at 5W, another does 100W and Thunderbolt 4, and they look identical in the drawer.

WhatCable sits in your menu bar and reads the cable data your Mac already has access to. Plug in a cable and it tells you in plain English what it can actually do: charging wattage, data speed, display support, Thunderbolt, etc.

Built in Swift/SwiftUI. Open source, free, no tracking.

GitHub: https://github.com/darrylmorley/whatcable

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