How to steady a shaky mouse pointer on a Mac
With a hand tremor, from essential tremor, Parkinson's, a medicine, age or plain tiredness, the pointer shivers around whatever you aim at. Buttons are hard to hit, and the click often lands beside them.
The short answer: macOS has no setting that removes shaking. It can make the pointer slower and bigger, give more time for a double-click, and let you click with the keyboard or your voice instead. To take the shake itself out of the pointer, while normal movement stays quick, you need a tremor filter: an app such as StillMouse on the Mac, or a hardware filter box.
Why does the mouse pointer shake on a Mac?
The Mac moves the pointer exactly as the mouse or trackpad moves, so it copies the tremor too. Nothing is wrong with the mouse. A tremor is a fast back-and-forth movement, about 3 to 12 times a second. Movement you mean is slower, mostly under about 2 times a second. That difference is what a tremor filter uses; macOS lets both through.
Which macOS settings make a shaky pointer easier to use?
- Lower the tracking speed. System Settings › Mouse › Tracking speed, or for a trackpad System Settings › Trackpad › Point & Click › Tracking speed. The same shake then moves the pointer less, but every movement across the screen takes longer too.
- Turn off pointer acceleration. System Settings › Mouse › Advanced… › Pointer acceleration. With it off, the same hand movement always moves the pointer the same distance, so a quick shake doesn't throw it further than a slow movement would.
- Make the pointer bigger. System Settings › Accessibility › Display › Pointer size. A bigger pointer is easier to keep in sight while it moves.
- Check the double-click speed. System Settings › Accessibility › Pointer Control › Double-click speed. Slower gives you more time for the second click; accidental clicks explains when faster is better.
- Click without the mouse when the pointer won't settle. Mouse Keys (in System Settings › Accessibility › Pointer Control) moves and clicks with the keyboard, and Voice Control clicks what you name.
What can't macOS settings do?
They calm the shake on screen only by slowing all movement down: a lower tracking speed makes long moves as slow as it makes the shake small. No macOS setting tells a shake apart from a movement you mean, keeps the pointer still while the button is down, or ignores a click you didn't mean.
How does a tremor filter steady the pointer?
A tremor filter treats the fast part of the movement as shake and takes it out, and lets the slow part through. Plain smoothing, which averages the last few positions, calms the shake too, but the pointer lags behind the hand, and less lag means more shake left. In StillMouse's own measurement, with a steady 6 Hz shake and the same 25 ms delay, plain smoothing left 66% of the shake; following the shake and subtracting it left 7%. A shake that changes from second to second is harder to remove.
The second half is the click. People with motor difficulties slipped while the button was down in 28.1% of clicks in one study (Trewin & Pain, 1999), against 6.3% for others. A filter that holds the pointer still while the button is down keeps the click on its target.
Is there hardware that steadies the pointer?
A trackball lets the hand rest while a finger or thumb moves the ball, and its buttons are pressed apart from the movement; see which mouse works best with a tremor. Filter boxes that sit between the mouse and the computer exist too; the Mac options compares them.