What's actually plugged into each port.

Cable Detective reads the macOS I/O Kit registry and tells you exactly what your USB-C, Thunderbolt, and MagSafe ports are doing right now. On your Mac. Nothing leaves the device.

Get Cable Detective

One-time €9.99. No subscription. No account. No cloud.

Cable Detective showing a MagSafe 3 port charging at 86 W, with cable e-marker, power, speed, and protocol details.

Plug it in. See what it really is.

USB-C ports look identical. They behave wildly differently. Cable Detective shows the truth for each one.

Power direction and wattageWho's charging whom, and at what negotiated wattage. PD contract source, advertised PDOs, charger rating.
DisplayPort lane stateHow many lanes are running, at what link rate. Whether DP-Alt Mode is actually active.
Cable identitySOP / SOP' / SOP" e-marker reads. Vendor IDs decoded. No invented specs when the cable doesn't answer.
USB transportUSB 2.0 vs 3.x SuperSpeed vs USB4 vs Thunderbolt. The lane state, not the marketing on the box.
Plain-English explanationOptional Apple Intelligence layer that summarises the report. Off by default. On-device only.

Every port. Every detail.

A live walkthrough of one MacBook Air. Four physically identical USB-C ports doing four very different jobs - and the Local AI panel that explains each one in plain English, on-device.

Cable Detective showing MagSafe 3 #1 charging at 65 W. The hero card decodes the cable as a genuine Apple MagSafe 3 charging cable paired with a 65 W charger.

MagSafe 3 - Power-only cable, 65 W of 65 W negotiated, USB Power Delivery contract decoded, no overcurrent events.

Cable Detective showing USB-C #2 with an Anker hub carrying USB data plus DisplayPort video at HBR2.

USB-C with hub + video - Anker hub, six USB devices behind it, DisplayPort 5.4 Gbps (HBR2) on 2 lanes, USB 2.0 lanes carrying the data.

Cable Detective showing USB-C #1 with a USB 2.0 link to an Apple MagSafe Charger - the cable is wired for SuperSpeed but the link runs USB 2.

USB-C 2 link - The cable is wired for USB 3.x SuperSpeed but negotiated down to USB 2 only. The Mac is powering the device at 15 W. The detail page tells you which side gave up.

Cable Detective showing USB-C #4 with a cable seated but nothing connected - waiting state, no power flowing, configuration channel only.

Cable seated, nothing talking - The Mac sees the plug but no device is negotiating. Likely the other end is unplugged, the device is off, or it's a charge-only cable with no charger attached.

Cable Detective Settings - Local AI tab. The Apple Intelligence section has buttons that deep-link directly to the macOS Apple Intelligence settings pane and to Apple's official 'Turn on Apple Intelligence' guide.

Local AI - Apple Foundation Models, on-device only. Buttons deep-link straight to the macOS Apple Intelligence pane and the official Apple activation guide. Nothing leaves your Mac.

Cable Detective Settings - General tab. Live cable monitoring section explains that verdicts refresh automatically and the section is about cable state, not Cable Detective software updates.

Live cable monitoring - Verdicts refresh the moment a cable is plugged in, unplugged, or renegotiates power. No polling, no flicker, no software updates pinging.

Zero network. Not a slogan.

Cable Detective has no network entitlement. There is no server. No account. No telemetry. No analytics SDK. No crash reporting. The optional AI explanations run on Apple's on-device Foundation Models on your Mac.

If we wanted to phone home, we would need to ship a new build with new entitlements. We don't.

Read the full Privacy Policy

Pricing

€9.99

one-time. No subscription.

Lifetime use of the version you bought.
No account. No cloud. No telemetry.
Family Sharing supported via Mac App Store.
Source: closed. Distribution: Mac App Store.

Coming soon to the Mac App Store

Submission in progress. Sign up for an email when it ships:
[email protected]

Common questions

Why does my "USB-C" port only do USB 2.0?: Because the cable, the host port, or the device chose to. Cable Detective tells you which one. SuperSpeed needs a SuperSpeed-capable cable on a SuperSpeed-capable port — many bundled cables are USB 2.0 only.
It says my charger is delivering 86 W. The label says 96 W. Bug?: No. 86 W is the negotiated USB-PD contract right now (laptop's request × charger's offer × cable rating). The charger's capability is on the box; the negotiated contract is what's actually flowing.
Can it tell me if my cable is fake?: It can tell you what the cable's e-marker chip claims (or that it has none). It cannot test the conductor quality. A cable that lies in its e-marker is rare; a cable with no e-marker chip at all is common and limits negotiated wattage to 60 W.
Does it work on Intel Macs?: No. Apple Silicon only.
Does the AI explanation send anything to a server?: No. It uses Apple's on-device Foundation Models. The app has no network entitlement at all.
Is there a free trial?: Mac App Store doesn't support free trials for paid apps. €9.99 is the one-time price.