Haptic feedback on a Mac trackpad: what it can do and how to get more of it

The trackpad on every modern MacBook does not click. It feels exactly as if it does, which is the clever part, but the glass surface does not move more than a hair when you press it. What you feel is a small motor underneath tapping back at your finger at the exact moment the pad decides you have pressed hard enough. That motor is the haptic engine, and it can do a lot more than fake a click.

How it works, in plain terms

Under the glass there is a set of force sensors and a small linear actuator, which Apple calls the Taptic Engine. The sensors measure how hard you are pressing. When the pressure crosses a threshold, the actuator fires: a tiny mass is pushed sideways and stopped, very fast, which you feel through the glass as a sharp tap. Your finger reads that tap as "the button went down", because that is what a button going down feels like.

Three things follow from this.

• The pad vibrates; it does not move. There is no hinge and no travel. A powered-off MacBook's trackpad feels like a dead slab of glass, because nothing is firing.
• The click is a sound and a feel, both made by the actuator. The click noise you hear from a MacBook trackpad is the actuator itself. Turn the Mac off and press: silence.
• The tap can fire for any reason, not just a press. The threshold click is just the default use. Software can ask the engine to tap at any moment, with any pattern.

Pressing harder past the first click produces a second, deeper tap. That is Force Click, and it is the first place most people notice the engine doing something beyond a plain click.

Which Macs have it

Any Mac with a Force Touch trackpad:

• MacBook Pro from early 2015 onward
• The 12-inch MacBook (2015 to 2019)
• MacBook Air from late 2018 onward
• Magic Trackpad 2 (2015) and the later Magic Trackpad, on any Mac

Older MacBooks and the original Magic Trackpad have a mechanical hinge and no actuator. The Magic Mouse has no haptics at all, and nor does any third-party mouse, which comes up again below.

Where macOS uses it today

Apple uses the engine quietly and in a handful of places. Once you know the list you will notice them.

• The click itself, and the second-stage Force Click for Look Up, Quick Look and data detectors.
• Alignment guides. Drag an object in Keynote, Pages, Numbers or Preview's markup tools and you feel a small tap when it snaps to a guide or to another object's edge.
• Scrubbing in QuickTime. Fast-forward and rewind with pressure, and each speed step is a tap.
• Calendar. Dragging an event's edge, you feel it snap to each interval.

It is a short list, and it has not grown much in years. Most third-party apps never touch it. The engine is capable of far more than it is asked to do.

What third-party apps can trigger

Apple gives developers a simple public API with three feedback patterns: a generic tap, an "alignment" tap and a "level change" tap. It works, with one big limitation: it only fires for the app that is in front. A utility running in the background, which is what most haptics-related tools are, cannot use it at all.

So the background tools that add haptics to a Mac, including qliqr, drive the actuator through a lower-level route, the same one other haptic utilities use. The engine does what it is told, in any app, as long as a finger is resting on the pad.

What that makes possible:

A tap on every click. Mouse down, mouse up, or both. On a trackpad this doubles the sensation of a click; on a laptop with a silent, light-touch pad it makes clicks feel like something again.

A notch on every scroll step. This is the one people do not expect, and it is the best use of the engine. As you two-finger scroll, the pad ticks under your fingers at regular intervals, like a scroll wheel with detents, or a dial with stops. You can feel how far you have scrolled without looking. In the app, the spacing is adjustable (every notch, every second, every fourth), and the tick can continue while a page coasts after a flick or stop as soon as your fingers lift.

Fine Tickabout this sound Ratchetabout this sound

Those are two of the scroll sounds the app pairs with the notches: a hairline tick and a firm toothed click. With both the sound and the haptic on, a long scroll feels like running a thumb along a ratchet.

Patterns. Two quick taps for a double-click, a tap on each stage of a drag, a short run of taps for a gesture. The engine can fire again within a few hundredths of a second, so short rhythms are possible.

What is not possible, on current hardware, is strength. The actuator has a fixed set of waveforms and all of them feel about the same on a modern Mac. There is no "soft tap" versus "hard tap"; there is just "tap", and the only ways to make one feel bigger are to fire twice or to pair it with a sound.

Limits worth knowing

• No haptics on a mouse. The engine lives in the trackpad. If you use a Magic Mouse or any other mouse, clicks can have a sound and a ripple on screen, but nothing taps back. There is no way around this short of a haptic mouse, and nobody makes one that works with macOS.
• You feel it only while touching the pad. The tap is transmitted through the glass. If your finger is in the air between clicks, you will feel nothing; if you click with one finger and rest another on the pad, you feel it through the resting one.
• Trackpad only, not keyboard. Key presses do not fire the engine, and the app does not listen to the keyboard at all.
• Bluetooth adds a little delay. On a Magic Trackpad the tap arrives a few milliseconds after a built-in pad would, which is rarely noticeable but is real.
• It is a private route. The low-level actuator interface is not something Apple documents, so a future macOS could change or remove it. Tools that use it load it at runtime, and if it disappears, haptics quietly stop while everything else keeps working.

The accessibility angle

A trackpad that taps back is useful beyond feeling nice.

If you cannot hear a click, or work with the sound off, a haptic tap is a confirmation that the click registered, delivered through your fingertip rather than your ears. Scroll notches tell you how far a page has moved without needing to see it. For anyone who finds the modern, silent, travel-free trackpad hard to trust, a physical tap per click restores the thing that was removed when the hinge went away.

It also works the other way. The sound, the on-screen ripple and the haptic are three separate channels for the same event, and you can keep whichever ones suit you. Sound off in a quiet office, ripple off in a screen recording, haptics on under the finger: each is a single switch.

None of this is a medical device and it does not claim to be. It is a trackpad that gives you more information about what you just did, in more ways than the default.

Trying it

If you have a Force Touch trackpad, the fastest way to feel the difference is to turn on scroll notches and scroll a long page. Within a few seconds it feels like the trackpad always should have worked this way; after a day, the default feels oddly numb.

The Mac app is at /mac. It is free, needs Input Monitoring permission to notice clicks and scrolls (it never reads the keyboard), and the haptics are a single switch in Settings under Haptics, with a "Try it" button that runs a short demo of notches and a double tap. If you do not have a Force Touch pad, the switch is there but nothing fires.

To hear the sounds that pair with it, without installing anything, the mouse click sound tester plays every click in the browser.

And for an idea of what tactile feedback feels like when every control has a different one, the fidget board has switches, dials and a click pen, each with its own resistance.