WhatCable

WhatCable is a macOS menu-bar utility and bundled CLI for inspecting USB-C cables, connected-device topology and charging behavior. It helps people troubleshooting docks, slow storage, displays or charging distinguish the Mac port's capability from the cable and the device. It reads port and power information exposed by IOKit, including cable e-marker data when available, rather than electrically certifying a cable.

Installation and supported hardware

Extract the official ZIP and move WhatCable.app to Applications, or use brew install --cask whatcable. The exact1.4.0 ZIP is17,166,182 bytes. The publisher requires macOS14 or later and Apple Silicon; Intel Macs do not expose the USB-C port-controller data needed for the cable reports. A usable USB-C connection and supported hardware data are necessary. No fixed RAM minimum is stated. Not every passive cable has an e-marker, and docks, adapters and firmware can limit what macOS reports.

Features and paid diagnostics

The basic app reports cable speed/power capability, connected devices and plain-language link or charging bottlenecks. Optional Pro features include live power measurements, negotiation/display diagnostics and saved cable history. Repository code is MIT by default, while the proprietary WhatCablePlugins subtree has separate reserved rights. Pro is a separately purchased license; a free/open-source core does not mean every bundled feature is unrestricted or free. Consult the current Pro page for price and terms.

Permissions, accounts and networking

The publisher describes local IOKit reads without helper daemons or special entitlements. Ordinary cable inspection is local and does not require a cloud account. Update checks contact GitHub periodically. Reporting a cable opens a pre-filled GitHub issue containing hardware capability data, which is not submitted until you do so and becomes public when submitted. Contribute Diagnostic Data is a separate opt-in action that sends anonymized port/power details. Review these payloads before sharing; using GitHub or activating Pro has its own account/network requirements.

Interpreting results safely

Negotiated charging wattage is not always current power consumption: a full battery, charge limit or inactive charger can explain a low or absent charge. Advertised cable capability, actual live link and device maximum are different measures. Certification is voluntary, and an unlisted USB-IF identifier is not automatically a bad cable. Treat the verdict as diagnostic evidence, not a guarantee against electrical damage or a replacement for physical inspection. The official screenshot shows1.3.0, so its layout is illustrative rather than an exact1.4.0 capture.

Sources: Official project and privacy, Pro, Licensing, Exact releases.