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 €4.99. 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.

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

Requirements

Mac: Apple Silicon (M-series). Intel Macs not supported.
macOS: 26 (Tahoe) or later.
AI feature: Optional. Requires Apple Intelligence enabled in System Settings.
Permissions: USB device entitlement. No file access, no network, no camera, no microphone.

Pricing

€4.99

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:
arti.ficial@fullstackoptimization.com

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. €4.99 is the one-time price.