Spindump

Click the More button (the three dots) at the top of the Activity Monitor window and choose Spindump. You may be asked for an administrator password. The report opens when it is done, and you can save it.

Create it while the app is hung, not after, so the report captures the problem.

Attach it to a bug report to the app's developer or to Apple through Feedback Assistant. The report can include the names of apps and processes you are running, so review it before sharing it publicly.

The spindump command samples every process on the Mac, so it must run as root. It only records what processes are doing and does not stop them.

1. Open Terminal while the app is still hung.
2. Run sudo spindump Safari -reveal, replacing Safari with part of the app's name. Enter your administrator password when asked.
3. Wait while it samples. The default length is 10 seconds.
4. When it finishes, the report is saved in /tmp, and the -reveal option shows it in Finder.

The app you name is listed first, and every other process follows. Each process shows its threads and the call stacks seen while sampling.

• By default, stacks are sorted by count. A line that starts with 84 was seen in 84 samples.
• A star (*) at the start of a frame marks kernel code.
• The deepest frame on each stack shows whether the thread was running or suspended.
• If the app's main thread is suspended waiting on another process, look at that other process in the same report. That is the main advantage over a single process sample.

When you force quit an app that was not responding, macOS can create a report automatically and may offer to send it to Apple. These reports are stored in /Library/Logs/DiagnosticReports.

You can browse them in the Console app, in Applications > Utilities. Under Reports in the sidebar, look at Spin Reports and Diagnostic Reports. Select a report to read it.

Reports you take yourself from Activity Monitor open in a window when they finish. Save the report from that window before you close it, so you have a copy to send.

Activity Monitor's More menu offers several reports. Pick the one that matches the problem. A spindump is much larger than a sample because it includes every process, and System Diagnostics takes longer still and shows a privacy notice before it runs. If a developer asks for a sample, send a sample. If Apple Support asks for a specific report, send that one.

• Sample Process: one process, about 3 seconds. Use it when you know which app is stuck or busy.
• Spindump: every process on the Mac. Use it when an app hangs and the cause may be another process.
• System Diagnostics: a larger report built from logs across the Mac, usually requested by Apple Support.