HN · HACKER_NEWS// 3h agoOPENSOURCE RELEASE

WhatCable explains what USB-C cables do

WhatCable is a tiny open source macOS menu bar app that reads the cable and power-delivery data your Mac already exposes and translates it into plain English. It tells you whether a plugged-in USB-C cable is charge-only, slow USB, 60W/100W/240W capable, Thunderbolt/USB4, or carrying display data, and it can also show charger PDOs and negotiated power details. Built in Swift/SwiftUI, it is free, open source, and says it does not track users.

// ANALYSIS

Strong niche utility: it takes low-level IOKit and USB-PD data and turns the usual cable mystery into something instantly legible.

–The core value is real: USB-C cables are visually identical but materially different, so a menu bar readout is the right UI for quick diagnosis.
–The implementation feels disciplined: native macOS, no helper daemon, no private API, and a narrow feature set centered on the actual hardware metadata.
–The main limitation is also clear from the repo: it is macOS-only, works best with e-marked cables, and some newer PD variants may need decoder updates.
–The product is more “excellent utility” than broad platform play, which is exactly why it works.

// TAGS

macosswiftswiftuimenu-barusb-cthunderboltusb-power-deliveryopen-sourceutilityhardware

DISCOVERED

3h ago

2026-05-01

PUBLISHED

6h ago

2026-05-01

RELEVANCE

5/ 10

AUTHOR

sleepingNomad