How a mouse jiggler works on Mac
Your Mac or MacBook watches for activity. Mouse, keyboard, trackpad. Go idle for a few minutes and macOS dims the screen, then sleeps.
A mouse jiggler for Mac nudges the cursor at regular intervals. Tiny movements. macOS thinks you're still there, resets the idle timer, and everything you had running keeps going. That's the whole trick.
Software vs. hardware
Hardware jigglers are USB dongles. Plug one in and it wiggles your mouse. Simple, works on anything. But it's another thing to buy and carry around, and it has no idea what's going on. It'll keep jiggling at 2 AM when you actually want to sleep. It'll jiggle while you're on a video call. It doesn't care that you're on battery.
Software jigglers like Shake It On have context. You pick when it runs: work hours only, plugged in only, only when a certain app is open. Rest of the time it sits in the menu bar doing nothing.
When you'd actually want one
Nobody needs their Mac awake all the time. But sleep causes real problems in specific situations. Big downloads fail when your Mac nods off mid-transfer. Presentations dim at the worst possible moment. Remote desktop sessions drop because the host went idle. Video renders lose hours of progress. Slack marks you "away" because there's no mouse activity even though you're right there reading.
And if you're at a company where IT locked down the Energy Saver settings? You can't even change the sleep timeout yourself.
Why not just change your sleep settings?
You could drag Energy Saver to "Never" and be done with it. But then your Mac never sleeps. Ever. Until you remember to change it back. Forget overnight on a laptop and it's dead by morning.
Corporate environments make this worse. IT locks those settings with MDM profiles. Literally can't change them. A mouse jiggler sidesteps all of this because macOS can't tell the difference between a jiggler and a real person moving the mouse. It's real input events at the OS level.
What to look for in a mouse jiggler app
Not all jigglers are equal. The bad ones teleport your cursor to random spots. Obvious and jarring. What you actually want:
Smooth movement. Shake It On uses sine-wave curves. Looks like someone bumped the desk, not like a robot took over your mouse.
Conditions. Pause for video calls. Pause on battery. Stop outside work hours. Without conditions you're manually toggling the thing every time, which defeats the purpose.
Configurable distance and timing. Sometimes you want invisible micro-movements. Sometimes you want something bigger. Being able to dial both in matters.