Knock turns taps on your MacBook into instant actions. Switch tabs, change desktops, play/pause music, open apps, run custom scripts, or take screenshots - all with a simple knock. Tap the desk beside your laptop or knock on the MacBook’s chassis (not the trackpad). Knock uses the built-in accelerometer in Apple Silicon MacBooks to trigger customizable shortcuts.
Hey everyone! I’m Will, the creator of Knock.
The idea started pretty simply. I noticed Apple Silicon MacBooks have a built-in accelerometer, but nothing really uses it. I started experimenting with it and realized you could actually detect taps or knocks on the laptop.
That turned into a simple idea: what if you could control your Mac just by knocking on it?
Knock lets you trigger actions like switching tabs, changing desktops, play/pause, launching apps, running custom scripts, or taking screenshots - just by tapping the desk beside your MacBook or knocking on the chassis.
One of the trickiest parts was making the detection reliable enough to feel natural. I ended up building a live “Knock Test” tool inside the app so users can tune sensitivity and see exactly what the sensor is picking up.
This is the first public release, so I’d love feedback from the community - especially on gestures, actions, or ideas for new features.
Thanks for checking it out 🙏
@will_gee1 This is so cool! I'm guessing this is similar to how you can double-tap the back of some devices (e.g., Pixel) to take a screenshot or perform other actions?
Fellow Mac developer here — this is a brilliant use of the Apple Silicon accelerometer. I've worked extensively with macOS system APIs and always wondered why nobody tapped into (pun intended) the motion sensor for UX. The 500ms typing suppression is a smart design choice. Quick question: have you looked into using the accelerometer's frequency spectrum analysis instead of just impulse detection? Could potentially let you distinguish between knocks of different intensities for even more gesture types. Really impressive first release, congrats!
Congrats on the launch! Just a quick quest: Beyond the basics, have you thought about multi-knock patterns to layer in more gestures without overwhelming the tuning?
This is such a creative hack of hardware that Apple left sitting there unused. The accelerometer-based detection is clever, and the fact that you built a live waveform viewer for tuning sensitivity shows real attention to UX. I can see this becoming muscle memory fast for things like play/pause during calls or switching desktops hands-free. Have you thought about adding rhythm-based patterns — like a specific knock cadence to trigger different macros? That could open up a whole new layer of interaction without needing more hardware.
Super creative use of the built-in accelerometer. How do you handle distinguishing between intentional knocks and vibrations from nearby objects, like someone else working at the same desk? Also curious if you plan to support custom gesture patterns beyond single, double, and triple knocks. Looks great!
@will_gee1 This is one of those ideas that sounds like a gimmick until you actually think about the use cases. Tapping to play/pause while your hands are off the keyboard, or switching desktops without reaching for the trackpad mid-flow - that could genuinely become muscle memory fast.
The fact that you built a live sensitivity tuner shows you've thought about the real problem here, which isn't detecting a knock - it's not detecting everything else. How does it handle false positives in noisy environments? Like if I'm at a coffee shop and someone bumps the table, or if I'm typing aggressively - does the accelerometer distinguish between a deliberate knock pattern and ambient vibration?
Also curious whether you've considered double-knock or triple-knock as separate triggers. That would open up a lot more actions without overlapping.
Really creative use of hardware that's just sitting there unused. Following this one.
This is actually really interesting! I didn't know that MacBooks could detect knocks! Other than the physical interaction aspect for Knock, are there features that Knock offers that others (like Raycast) doesn't?
Knock on your MacBook to control your Mac? My cat already does this—except it’s more like “paw aggressively at the hinge until something happens.” If this can distinguish between intentional knocks and feline percussion, you’ve solved the real edge case.
What an original idea! how sensitive is the detection? im curious if it picks up accidental bumps or if you had to tune a threshold to avoid false triggers.
@will_gee1 This innovation looks fun as hell. Can you reveal more about the technical part of Knock? How does it work? How did you make this possible? Can the mac get damaged in the long-term by trying to use it in a non-intended way? (this last one is really silly, but I wanna know lol)
Will G