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YOU CAN TURN YOUR MACBOOK INTO A KITCHEN SCALE

A free macOS app that reads the Force Touch pressure sensors in your MacBook trackpad and shows the weight of what you put on it — no hardware, just software.

by Krish Shah

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difficulty
●○○○○
time
five minutes
license
MIT
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repo ACTIVE9,167 stars
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COMPAREE VERDICT

TrackWeight is exactly what it sounds like: a free macOS app that turns your MacBook trackpad into a scale by reading the Force Touch pressure sensors. You rest a finger on the trackpad (the sensors only report pressure when they detect capacitance), place the object while keeping contact, press as lightly as possible, and read the weight in grams. Krish Shah checked the readings by putting the MacBook on a conventional digital scale and comparing known weights. The catch is the finger — you cannot weigh something on its own, you have to keep touching the trackpad, and metal objects may be detected as a finger themselves (put paper or cloth under them). It needs a MacBook with a Force Touch trackpad (MacBook Pro from 2015 or MacBook from 2016 onward) and macOS 13 Ventura or later. The DMG builds are unsigned, so macOS may ask you to allow the app in Security & Privacy. It is a fun novelty more than a kitchen tool, and the README is upfront that it is experimental — but if you already own a Force Touch MacBook and want to weigh something small without a scale, it costs nothing to try. The thing most likely to trip you up is lifting your finger and losing the reading.

GOOD TO KNOW

  • —This is a macOS application, not a hardware build — no parts to buy, no printing, no soldering.
  • —The README explains how it works, how to install it (DMG, Homebrew or build from source) and how the readings were checked (MacBook on a digital scale, known weights).
  • —Source code is in the repo (SwiftUI, Combine) and uses a custom fork of the Open Multi-Touch Support library by Takuto Nakamura to read the pressure data.
  • —Licence is MIT.
  • —App Sandbox is disabled for low-level trackpad access; the DMG builds are unsigned, so macOS may ask you to allow the app.
  • —A disclaimer in the README says it is for experimental and educational purposes, not for critical measurements or commercial applications where precision is essential.

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Can I build this?

Printnothing required — software only
Buynothing required if you already own a MacBook with Force Touch trackpad (2015+ MacBook Pro, 2016+ MacBook)
ToolsmacOS 13 Ventura or later; Homebrew if you install from the command line; Xcode 16.0+ and Swift 6.0+ only if you build from source
Skillsnone for the DMG install; comfortable with the command line if using Homebrew; Xcode and Swift knowledge if building from source; no hardware skills at all
TimeA few minutes to download and open the DMG, or one command if you already have Homebrew.
Costfree — the app and code are free (MIT licence); you need a MacBook with a Force Touch trackpad
SafetyNothing physical. App Sandbox is disabled so the app can read the trackpad, which gives it more system access than a sandboxed app; the code is open for review.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

Your MacBook Trackpad is a SECRET Scale! (Genius GitHub Hack)3:29

Thomas Dye tests TrackWeight with a fish food tub (23 Jul 2025). Krish Shah's own demo is a post on X.

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Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Check your MacBook model and macOS version(You need a MacBook with Force Touch trackpad (MacBook Pro 2015 or newer, MacBook 2016 or newer) and macOS 13 Ventura or later. If you are on an older model or macOS version, the app will not work.)
  2. 2.Download the DMG from the GitHub Releases page (Or install via Homebrew with: brew install --cask krishkrosh/apps/trackweight --force)
  3. 3.Open the DMG and drag TrackWeight.app to Applications(The builds are unsigned, so macOS may block the first launch — allow the app in System Preferences > Security & Privacy.)
  4. 4.Launch the app, rest one finger on the trackpad, place the object while keeping contact, and read the weight(Press as lightly as possible while keeping your finger on the trackpad. Without finger contact there is no reading. Put paper or cloth under metal objects.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • You cannot weigh something without keeping a finger on the trackpad — the pressure sensors only report data when they detect capacitance.
  • Metal objects may be detected as a finger touch themselves, so you may need to place paper or cloth between the object and the trackpad to get an accurate reading.
  • The app is for experimental use — the README says not to use it for critical measurements or commercial applications where precision is essential. Verify with a real scale for anything that matters.
  • The DMG builds are unsigned, so macOS may block the first launch until you allow the app in System Preferences > Security & Privacy.
  • It needs a Force Touch trackpad: the README lists MacBook Pro 2015 or newer and MacBook 2016 or newer, with macOS 13 Ventura or later.
  • If you build from source, you have to disable App Sandbox in the Xcode project settings, otherwise the app cannot read the trackpad.

How accurate is it?

The README says the pressure data from the multitouch library is already in grams, and the readings were checked by placing the MacBook on a conventional digital scale and comparing known weights. It gives no accuracy figure, and its disclaimer says the app is for experimental and educational use, not critical measurements.

Can I weigh something without keeping my finger on the trackpad?

No. The trackpad only reports pressure when it detects capacitance (a finger touch), so you rest a finger, place the object while keeping contact, and press as lightly as you can.

Will this work on my Mac?

The README lists a MacBook with a Force Touch trackpad — MacBook Pro from 2015 or newer, or MacBook from 2016 or newer — running macOS 13 Ventura or later. Other Macs are not mentioned.

Why does macOS warn me when I open it?

The DMG builds are unsigned, so you may need to allow the app in System Preferences > Security & Privacy. App Sandbox is disabled in the project because the app needs low-level trackpad access, which gives it more system access than a sandboxed app. The code is open source under MIT, so you can review it.

Can I use this for coffee dosing or other precision tasks?

The README's disclaimer says it should not be used for critical measurements or commercial applications where precision is essential. If precision matters, check against a calibrated scale.

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Discussion1

FROM THE COMPAREE TEAM

The app reads trackpad pressure data that normal macOS apps cannot access, and according to the README the raw numbers are already in grams. What would you weigh first — coffee beans, a letter, or something else small enough to fit on a trackpad?

CompareeTEAM1d ago

Checked against the README: the app is free via DMG or Homebrew and the code is MIT-licensed. Thomas Dye's test video (YouTube 8gxijdHaZTQ) shows it weighing a fish food tub on the trackpad. The main limitation is the finger — the sensors only report pressure while they detect a touch, so you have to keep a finger on the trackpad the whole time. The README is upfront that it is experimental and not a replacement for a real scale.

Krish Shah

Krish Shah (GitHub @KrishKrosh) built TrackWeight as a free macOS app to turn the Force Touch trackpad into a weighing scale. He calibrated it by placing the MacBook on a digital scale and comparing known weights, and released it under the MIT licence with a disclaimer that it is for experimental and educational use.

GitHub

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