# Free App Turns Your Mac Into a USB-C Cable Tester

WhatCable app reveals the true capabilities of your USB-C cables.

- **Source:** [SlashGear](https://www.slashgear.com)
- **Published:** 2026-08-05
- **Original article:** <https://www.slashgear.com/2227785/free-app-turns-mac-into-usb-c-cable-tester/>
- **On Brifing:** https://brifing.si/s/a0ccdb16-8348-4efa-b9bb-a5146b9b57a3

## The USB-C Cable Confusion

While USB-C appears universal, cables vary significantly. Different standards like Thunderbolt 4, USB4, and Power Delivery create performance gaps even with identical connectors. For instance, Apple's included USB-C cable doesn't support iPhone 17 Pro's 10Gbps speeds. This uncertainty leads users to accumulate drawers full of incompatible cables.

## How WhatCable Works

WhatCable analyzes true specifications of USB-C cables connected to Apple Silicon Macs. The free app requires macOS 14 or later. When you connect a cable, it instantly displays critical metrics like charging speed, data transfer capacity, and certification status. It monitors all ports including MagSafe in one dashboard.

## Charging Performance Analysis

WhatCable measures cable charging capacity in watts, showing whether it reaches your Mac's maximum power handling. It clearly warns about underperforming cables and verifies USB-IF certification to identify counterfeit products. The app makes technical specifications accessible through plain language notifications.

## Display Connection Troubleshooting

WhatCable solves resolution and refresh rate issues with USB-C monitors by displaying detailed technical specifications. It reveals compatibility gaps that macOS normally doesn't show, guiding users through USB-C's complex display standards. This is particularly valuable for creative professionals using external displays.

## E-marker Chip Detection

The app detects e-marker chips in cables that automatically communicate capabilities to connected devices. It lists all supported USB Power Delivery profiles and highlights the active one. This feature helps users understand unexpected charging speed reductions by showing the negotiated power contract.

## Menu Bar Integration

WhatCable can reside in your Mac's menu bar for instant access. You can enable automatic notifications when connecting new cables. The app also provides detailed information about connected USB hubs and flash drives. Remarkably, it correctly reports specifications even when cables are looped back into the Mac.

## Free vs Pro Version

While the free version suffices for basic users, professionals may need the Pro version. For a one-time $10 payment, it analyzes complex setups like daisy-chained monitors and multiple USB devices. The Pro edition offers deeper diagnostic data during data transfers and supports advanced troubleshooting scenarios.

## The Future of USB-C

Tools like WhatCable help address USB-C's fragmentation issues. Consumers buying devices without understanding cable specifications contributes to e-waste. By discovering your existing cables' true potential, you can avoid unnecessary purchases and make more sustainable tech choices in our connected world.

## Sources covering this story

- https://www.slashgear.com/2227785/free-app-turns-mac-into-usb-c-cable-tester/ — 

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_Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._