WhySlow
Understand the load.
Choose the next step.
WhySlow brings your Mac’s activity into one clear view. See likely bottlenecks, understand unfamiliar processes, and check whether a change helped.
Start with a diagnosis
CPU activity, memory pressure and available disk space give context to the symptoms you feel. WhySlow translates sampled readings into likely explanations. A short spike is not proof that an app is causing a persistent slowdown.
Put a name to background work
Processes such as kernel_task and mds_stores have useful jobs. Read what they do, why they may be busy and whether to leave them running. The process library uses the same catalog as the app.
Look beyond CPU
Review background items, check your internet connection and explore local usage history. Browser tools can find duplicate tabs after you grant permission to read the supported browser’s tabs. Permission is optional.
Take deliberate action
Explanations are free. The $7 license unlocks supported actions such as quitting an app group, closing selected duplicate tabs and rebuilding a Spotlight index. Save your work before closing apps; rebuilding an index starts more indexing work.
A glance at the menu bar
The next-release preview adds CPU and memory readings beside your other menu bar items. Explore the menu bar preview and its limits. These expanded readings are not in the current 1.0.0 download.
Your activity stays local
Running processes, tab details and usage history are processed on your Mac. License activation, update checks and an optional internet speed test have separate network needs, explained in our privacy policy.