A lightweight macOS menu bar utility that shows real-time USB-C and Thunderbolt port status. See what's connected, how fast it's running, and how much power each port is using.
Free and open source. Full detail on Apple Silicon; Intel Macs run in reduced detail (see Requirements).
- Port overview at a glance from the menu bar, with active count and power in/out
- Protocol detection for Thunderbolt 3/4/5, DisplayPort alt-mode, USB3, and USB2
- Connection lifecycle shown live: Detecting the instant a plug lands, Negotiating while the link trains, then the real details fade in
- Live lane status showing exactly which lanes are carrying data and at what speed
- Connections showing what the port has actually set up, and flagging anything macOS has blocked (the usual reason a dock's USB or display won't work)
- Display detail with link rate (HBR2/HBR3), lanes in use, native versus Thunderbolt-tunnelled, connected display count, and any hub or HDMI converter in the chain
- Power monitoring with real-time wattage, voltage, current, and a 60-second rolling graph
- Charging status that says why a connected charger isn't charging: charging, fully charged, held to protect battery health, or just not charging
- Device and dock identification including product name, vendor, serial number, USB version, and the connected Thunderbolt dock's own name. Behind a hub or dock, the row names the device you actually plugged in, not the hub, and the detail card counts the rest
- Charger identification naming the adapter and listing its full advertised power menu
- Cable info showing cable type and USB PD revision
- Liquid detection flagging a wet port (M3 and later)
- Thunderbolt capability showing max supported speed and lane width per port
- Port statistics with lifetime connection counts and error tracking, readable whether or not anything is plugged in
- MagSafe support with charging status and power draw
- Built-in updates with a banner when a new version is out and a one-click install, after checking the download is signed and notarised by Apple
- Menu bar or Dock with an optional window mode, and an optional port count next to the menu bar icon
- Adjustable text size scaling every panel, for high-resolution displays where the default feels small
- Menu and shortcuts with a right-click menu for Settings, Check for Updates, GitHub, About, and Quit, plus the standard Cmd+, and Cmd+Q
The live view tells you what your ports are doing right now. The Flight Recorder keeps watching when you're not, so you can catch the intermittent faults that only show up when nobody's looking. It runs always-on in the background, records each port's power, protocol, and link state to a local database, and survives restarts.
- Device tree per port. Every USB device behind the port: what's plugged into the dock, what's behind the hub inside it, and which hub or dock each device arrived through. Hubs sit behind a toggle so the devices lead.
- Event timeline. Every plug, unplug, protocol change, and power event over time, filterable by port and event kind.
- Power graphs. Power draw for every port across a selectable time range, with disk-backed history so it survives a restart.
- Port health scoring. Each port scored by how often faults recur, with a clear "not a hardware diagnosis" note. Reset the baseline once you've dealt with something.
- PD reliability counters. The port controller's own lifetime fault counts (hard resets, role-swap failures, short detections, bus errors) folded into each port's health score. Only faults that happen while WhatPort is watching count against you.
- Alerts. Get notified on overcurrent, link error, disconnect, or protocol downgrade.
- Sessions. Bookmark a stretch of recording, name it, and export it to JSON or CSV.
- Survives an overnight kill. With Launch at Login on, it restarts itself within seconds if macOS stops it to free memory. A deliberate Quit still quits.
£4.99 one-time, works on up to 2 Macs. Secure checkout via Stripe, your licence key is emailed instantly, 14-day refund if it isn't for you. Buy WhatPort Pro at whatport.app (terms, privacy).
The base app in this repository is the free, open-source half. The Flight Recorder is the paid part and is not included in the open-source build.
Download the latest release from the releases page, unzip, and drag WhatPort.app to your Applications folder. Or with Homebrew:
brew install --cask darrylmorley/whatport/whatportThe app is signed and notarized by Apple.
- macOS 14.0 (Sonoma) or later
- Apple Silicon (M1, M2, M3, M4, or later) for full detail
- Intel Macs are supported in reduced detail
Intel Macs don't publish the USB-C port-controller data Apple Silicon does, so some of what WhatPort reports simply isn't there to read. The app says so in a banner rather than showing blanks.
You still get: Thunderbolt ports and their link speed and width, the full device tree behind each port, and power. What's missing is the port-controller layer: per-port USB-PD contracts, pin configuration, and the port health counters.
Pure SwiftPM, no Xcode project needed:
git clone https://github.com/darrylmorley/whatport.git
cd whatport
make app # assemble WhatPort.appswift build compile-checks without producing a runnable bundle, make app assembles the .app, and make run launches it. No root access needed, all IOKit reads are unprivileged. The only entitlement the signed build carries is outbound network access, for the update check and Pro licence validation.
WhatPort correlates several unprivileged IOKit and SMC services per physical port. The main ones:
- AppleTypeCPhy for USB-C lane state (transport protocol, power level per lane)
- IOThunderboltPort for Thunderbolt link speed, width, and capability
- SMC and USB-PD for power, split into power in and power out (watts, voltage, current per port)
Connection events are detected via IOKit interest notifications for sub-second response. All state (connections, power, transports) is also polled every second as a safety net.
No analytics, no telemetry. The app reads local IOKit data and nothing else. The one network request it makes is the update check: it asks the GitHub releases API whether a newer version exists, and downloads it only if you click Update.
Layered, each layer depending only on the ones below it:
WhatPort SwiftUI app
├─ WhatPortPlugins Pro features (a stub in this open-source build)
├─ WhatPortAppKit plugin registry, wires Pro into the app
├─ WhatPortIOKit all IOKit C API interaction
└─ WhatPortCore pure-Swift domain model
- WhatPortCore: Pure Swift domain model and correlation logic. No IOKit or UI imports.
- WhatPortIOKit: All IOKit C API interaction. Nothing above this layer touches C pointers or IORegistry.
- WhatPortAppKit: The plugin registry that lets the Pro half attach to the app.
- WhatPortPlugins: The Flight Recorder and licensing. In this repository it is a stub with an empty
bootstrapPlugins(), so the app builds and runs without it. - WhatPort: SwiftUI views and formatting. No data fetching or business logic.