A few useful answers.

The practical details before you download.

What does WhySlow do?

It reads your Mac’s activity locally and explains likely performance bottlenecks, unfamiliar processes and possible next steps. Explore the features or try the sample demo.

Is WhySlow free?

Diagnosis and explanations are free. A $7 USD one-time license unlocks supported fixes on up to three Macs. See pricing and purchase availability.

Which Macs work?

WhySlow 1.0.0 requires macOS 15 or later and supports Apple silicon and Intel. Get the signed, notarized app on the download page.

Is WhySlow a Mac cleaner?

No. Mac cleaners delete caches and files to free space. WhySlow explains what is using your CPU, memory, disk and network, then suggests a specific next step, like quitting one app. It never deletes files. If storage is your problem, it tells you so.

Does it clean files or add RAM?

No. WhySlow helps explain load and offers specific actions. It does not add physical memory, guarantee a speed increase or delete your files as a general cleanup step.

Does it upload running apps or browser tabs?

No. This information stays on your Mac. License activation and update checks contact the service; a speed test contacts Apple only when you start it. See privacy details.

Why does it ask for browser access?

The Browser panel needs Automation permission to read supported browser tabs and close tabs you select. You can decline that permission and use other features. Get permission help.

Are the new menu bar readings in the download?

The expanded CPU and memory readings on this website are a next-release preview. The release notes describe what has shipped.

How do I activate or recover a key?

Open the app’s unlock screen and choose “Already have a license key?” to paste your key. Visit license recovery or contact support if you need help.

Can I get a refund?

Our terms and 30-day refund policy explain the process. Email support with your purchase details; never send payment-card information.