WhatCable Pro is a deep USB-C diagnostics tool designed specifically for Apple Silicon Macs running macOS 14+. While the free version identifies basic cable capabilities, the Pro tier offers advanced, real-time troubleshooting directly from IOKit data—requiring no extra software or root access.

Key Features

• Negotiation Diagnostics: Easily spot bottlenecks by comparing what your Mac port, cable, and connected device support side-by-side.
• Live Power Metering: Displays real-time wattage, voltage, and amperage per port, updating every 2 seconds.
• Hardware & Port Health: Tracks lifetime port errors, resets, and monitors liquid detection (LDCM) sensors.
• Advanced Insights: Offers Power Delivery (PD) contract inspection, cable resistance estimation, and DisplayPort Alt Mode lane mapping.
• Developer Friendly: Includes a CLI monitor mode (whatcable –monitor) and desktop widgets for quick tracking.

What's New:

Version 1.2.1:

Fixed

• Charger wattage no longer sticks at 3W when a second device is plugged in. Charging over MagSafe with a third-party adapter while also using a USB-C display (or anything else on a second port) could freeze the reading at "3W", even though the Mac was charging at full wattage. Unplugging the display used to be the only way to correct it. Thanks @hinaloe for the clear report and the diagnostics (#443).
• Intel Macs now say why the app can't work. WhatCable relies on data Intel Macs don't expose, so it can't report cables on them. Instead of an empty ports list, Intel users get a clear message explaining that (#407).
• Power Monitor explains a connected-but-not-selected charger. When a charger is plugged in but the Mac isn't drawing from it, the monitor used to spin forever (#296).
• The window comes to the front in window mode when reopened (#419).
• Updater gives clearer guidance when the app bundle is missing. If the running app was moved (for example, left in Downloads), the updater now explains what to do instead of failing with a cryptic error.

Screenshots:

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