# Uptime

Canonical page: https://vitalsmac.com/glossary/uptime

Activity Monitor glossary, Figures Activity Monitor leaves out. What is uptime on Mac?

Also: time since restart

**Short answer:** Uptime is how long a Mac has been running since it last started up. Sleep counts: closing the lid does not reset it, only a restart or a shutdown does. Activity Monitor does not show it; the `uptime` command in Terminal and System Information → Software do.

Macs are often up for weeks, because sleep is cheap and updates are the only thing that forces a restart. That is fine. macOS is built to run for months, and a long uptime is not by itself a reason to restart, whatever a support forum says about restarting every week.

Uptime becomes useful when something is wrong, because it separates the problems that a restart fixes from the ones it does not. Memory pressure that stays red after you quit the apps that caused it, a process that has been stuck for days, or kernel_task busy on a cool Mac are the restart cases. A Mac that is slow every afternoon is not.

## How to see uptime on a Mac

Open Terminal and type `uptime`. The line reads something like `14:32 up 12 days, 3:07`, followed by the load averages. System Information (hold Option and click the Apple menu) shows the same under Software → Time since boot.

Activity Monitor has no uptime figure. Its Energy tab has a 12-hour battery graph on a laptop, but nothing about when the Mac started.

## When to restart, and when not to

Restart when memory pressure stays yellow or red after you have quit the apps that were using the memory, since leaked memory in a system process is freed no other way. Restart when a process is stuck and Force Quit does not clear it, and after any macOS update that asks.

Do not restart for a slow afternoon, a hot MacBook or a full disk: those have causes you can see in Activity Monitor, and they come back after the restart. Find the app instead.

- Restart: red memory pressure that does not clear, a stuck process Force Quit cannot end, an update that asks for it.
- Find the cause instead: a Mac that is slow at the same time each day, heat under load, a disk filling up, an app that keeps growing in memory.

## Questions people ask

### How often should I restart my Mac?

When there is a reason: an update, memory pressure that stays high after you quit the apps behind it, or a process that will not end. There is no benefit to a weekly restart on a Mac that is behaving.

### Does sleep reset uptime?

No. Uptime counts from the last startup and keeps counting while the Mac sleeps. Only a restart or a shutdown resets it.

### Where do I see uptime in Activity Monitor?

Nowhere. Activity Monitor does not show it. Use `uptime` in Terminal or System Information → Software → Time since boot.

## In Vitals

Vitals shows uptime on the CPU card of its Overview, beside the load and the core count.

## Related

- [Memory pressure](https://vitalsmac.com/glossary/memory-pressure)
- [kernel_task](https://vitalsmac.com/glossary/kernel-task)
- [Load average](https://vitalsmac.com/glossary/load-average)
- [Not Responding](https://vitalsmac.com/glossary/not-responding)

Looking for something better than Activity Monitor? See [the best Activity Monitor alternatives for Mac](https://vitalsmac.com/best-activity-monitor-alternatives), or [every term in the glossary](https://vitalsmac.com/glossary).