What Is the Difference Between Free WhatCable and WhatCable Pro?

The free version of WhatCable explains the connection you have right now; WhatCable Pro adds the ability to inspect the evidence behind that explanation, watch measurements over time, and investigate changes. Both run the same diagnostic engine, the app is open source, and Pro is optional — so the free tier is the right starting point unless you need to dig into why a setup behaves the way it does.

What the free version covers

According to WhatCable's own description, the free tier is for "understanding the current connection." In practice that means:

• Charging diagnosis — see what the charger offers, what the cable supports, and whether the Mac is drawing the power it needs. The app explains the result rather than leaving you to swap parts at random.
• Cable identity — the cable's reported identity, speed and charging rating, plus the kind of connection in use.
• Whole-connection view — it reads the port, cable, charger, adapter and connected device together, then states the outcome in plain English.
• Technical details on demand — the original readings are available when you want them.

That set answers the common questions the app is built around: why a Mac is charging slowly, what a given USB-C cable can actually do, and what may be limiting a display connection.

What Pro adds

The site describes Pro as the tier to "inspect the evidence, watch measurements and investigate changes over time." Three additions follow from that wording:

The distinction is scope, not accuracy: free tells you what is happening and why, Pro lets you follow it as conditions change — for example, when a charger, cable or dock is swapped and you want to see what shifted.

How WhatCable reaches its answers

The method matters for judging whether the free explanation is enough. WhatCable reads the identity a cable reports, checks it against USB Power Delivery rules, and compares that with what the Mac actually negotiated. The site is explicit that it cannot see inside the cable jacket and does not claim to. So the output is a reading of reported identity plus observed negotiation — useful for spotting cables whose claims don't add up, but not a physical test of the wire.

A related feature is the public cable database: 145 cable observations at the time of the site text, searchable by vendor, speed and identity, and nothing is uploaded without your action. Browsing it can tell you whether your cable has been reported before — a check that works without Pro.

Requirements and availability

• Apple Silicon Mac, macOS 14 or later
• Signed and notarised
• Available in 19 languages
• Free download, with a Homebrew install option
• Open source, with Pro as an optional paid tier (a "Get Pro" link exists on the site; the page text does not state a price)

Which one you need

Choose free if your question is "why is this charging slowly?" or "what can this cable do?" and you want an answer for the setup in front of you. Choose Pro if you are comparing components, troubleshooting an intermittent problem, or want a record of how measurements change as you swap hardware. Because both share the diagnostic engine, starting free and upgrading only when you hit the limits of a single-snapshot explanation is the lower-risk path.