macOS brightness and volume move in big jumps — Glissé is a free app that makes them smooth

The problem

Tap the volume key on a Mac and the level jumps a sixteenth at a time. Brightness behaves the same way. Hold Option and Shift while you tap and you get quarter steps, which helps, but you are still tapping a key over and over to move a small amount — and with brightness you are doing that while staring at a screen that is too bright.

There is no way to simply slide to the value you want.

What Glissé does

Put one finger on the left edge of the trackpad and slide up or down: brightness. Do the same on the right edge: volume.

That is the whole interaction. No clicking, no modifier key to hold down, no window, no overlay. The real macOS HUD appears — the same one the keyboard produces — and the trackpad ticks under your finger as the value moves.

It sits in the menu bar as one small glyph. There is nothing to set up before it works.

What makes it worth installing

It does one thing, and it works the moment you install it. No configuration, no gesture builder, no preference pane to learn. The edges of your trackpad are simply sliders now.

It is free and open source under the MIT licence. No trial, no licence key, no account, no telemetry, no analytics, and no network code of any kind — the app makes no outbound connection, ever. The whole source is on GitHub, so you can read exactly what it does before you run it, or build it yourself if you would rather.

Two things here are easy to fake, and this does not fake them:

• The brightness change is the real backlight, not a dark overlay or a gamma trick.
• The on-screen display is the actual macOS HUD, not a lookalike drawn by the app.

How it knows you meant it

A gesture only starts if your finger begins inside the edge strip, and only if it is the only finger on the trackpad. A touch that starts in the middle and later wanders to the edge can never activate the slider, for its whole life. It also stops listening for half a second after every keystroke, so typing does not set it off.

Those rules are unglamorous, and they are most of the reason it feels like part of the system rather than something bolted on.

Features

• Left edge for brightness, right edge for volume — swappable
• Smooth control with the real system HUD
• Haptic ticks as the value moves: off, light, medium or strong
• Pauses for half a second after every keystroke, so typing never sets it off
• Fine-control mode for much smaller changes
• Bottom-quarter-only mode, if you ever trigger it by accident
• Optional modifier requirement — hold or toggle Control, Option, Command, Shift or Fn
• Optional pointer freeze while you slide
• Optional three-finger tap as middle click
• External monitor brightness over DDC
• Launch at login
• Menu bar only: no dock icon, no window

What you need

macOS 13 Ventura or later, and a Force Touch trackpad or a Magic Trackpad. On hardware with no actuator the haptics are skipped quietly and everything else works.

The main feature needs no permission at all. Sliding, volume and brightness all work the first time you launch it, before you have granted anything. Accessibility is requested only for the system HUD and three optional extras. The two event taps it installs are listen-only, so they physically cannot swallow or alter a keystroke.

Install

brew install --cask --no-quarantine helgafinn/tap/glisse

Or download the DMG from the releases page on GitHub.

The honest part

• The build is ad-hoc signed rather than notarised, because notarising needs a paid Apple Developer account this project does not have. That is what --no-quarantine is for, and it has a real cost: macOS forgets the Accessibility permission on every upgrade, so you have to grant it again.
• There is no App Store version and there cannot be one. Reading raw trackpad contacts, producing the system HUD and talking to a monitor over I2C have no entitlements available. This is a program you choose to trust, and it should say that plainly instead of implying that a review process vouched for it.
• External monitor brightness is written but not verified — no second display was available to test it on.
• Intel Macs and the standalone Magic Trackpad are also unverified. The code is there and compiles, but nobody has run it on that hardware yet.

Every private system call the app makes is listed in the README, each with the reason no public alternative exists.

Changelog

v1.0.0 — first release. Edge sliding for brightness and volume, real system HUD, haptics, typing suppression, fine control, bottom-quarter mode, optional modifier requirement, pointer freeze, three-finger middle click, DDC for external displays, launch at login.

AI disclosure

This post, and a large part of the app, were written with AI assistance. The list of unverified paths above is honest rather than promotional, and is the part worth checking for yourself.

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Source, README and issues: https://github.com/helgafinn/glisse