Frozen in place
As the lid passes 92°, your desktop is pinned where it is in the room. Every pixel of the glass then shows what you would see of that picture through it.
The iPhone Duo fold, for MacBook
Close the lid.
The desktop stays.
As the lid comes down, your desktop holds still in the room and softens into frosted light. Open it, and everything comes back into focus.
110°Scroll to close
- MacBook Pro 14″ and 16″
- MacBook Air M2 and later
- macOS 14 or later
- Apple silicon and Intel
- Free and open source
How it works
The picture stays.
The glass moves.
On iPhone Duo, the interface never jumps between screens. It holds its place, and the folding glass moves over it. Mac Duo gives your MacBook the same idea.
Frost from the far edge
Blur and darkness follow the picture, not the screen. The far edge dissolves first. Light leaks past the sides. The hinge stays sharp to the end.
Driven by the hinge
Nothing is pre-rendered. The lid angle is read a hundred times a second and smoothed with a spring. Stop halfway and it waits. Open again and it plays back.
Styles
Three looks.
Or make it yours.
Switch styles from the menu bar. Or open Settings and drag the sliders while the screen folds under your cursor.
Under the glass
Built like it belongs there.
- Metal
- One shader pass per frame, at your display's full refresh rate. Idle, it does nothing at all.
- 100 Hz
- The hinge sensor is read a hundred times a second, with prediction for fast closes and a spring for smooth ones.
- 0 bytes
- Frames live on the GPU for the moment the lid is moving. Nothing is saved. Nothing leaves your Mac.
- Focus on wake
- Open the lid and the desktop comes back into focus from frost, through the same curve.
- Menu bar
- A switch, three styles and the three sliders you actually reach for, without opening a window.
- Open source
- Swift and Metal, no dependencies, MIT licensed. Read every line on GitHub.
Get Mac Duo
Up and running in a minute.
- Download the disk image and drag Mac Duo to Applications.
- Open it. Mac Duo is signed and notarized by Apple, so it opens like any other app.
- Allow Screen Recording when asked. It's how Mac Duo sees the desktop while the lid moves.
Questions
Does it record my screen?
No. Capture starts only while the lid is closing towards the fold angle, frames stay on the GPU while the fold is on screen, and they're dropped the moment it ends. No files, no uploads, no accounts, no analytics. Read the privacy statement.
Will it slow my Mac down?
Not while the lid is still. Idle, Mac Duo reads a sensor a few times a second. Folding is one Metal pass per frame, which Apple silicon handles at the display's full refresh rate.
What happens when the Mac sleeps?
The fold plays until the lid's magnet switches the display off, a few degrees before fully closed. That's hardware; no app can keep the panel lit with the lid shut. Turn on Focus on Wake and the desktop comes back into focus when you open the lid.
Why do I see the login screen instead of the wake reveal?
macOS asks for your password immediately after the display turns off. Set System Settings › Lock Screen › "Require password after display is turned off" to a short delay, and reopening within it goes straight to your desktop, where Mac Duo plays the reveal. Mac Duo cannot draw over the login window.
Why did macOS say "Mac Duo" Not Opened?
Versions before 1.0.2 weren't notarized, so macOS Sequoia showed that warning on first launch. Since 1.0.2 every build is signed with a Developer ID and notarized by Apple, and the download opens without it. If you still have an older copy, download again from this page. The source is public on GitHub.
Does it work with an external display?
The fold plays on the MacBook's own screen. External displays are left alone.
Which Macs have the sensor?
MacBook Pro 14-inch and 16-inch from 2021 on, the 2019 16-inch MacBook Pro, and MacBook Air with M2 or later. On other Macs, Mac Duo stays quiet.
How do updates work?
Mac Duo checks GitHub Releases once a day, or whenever you choose Check for Updates. A new version downloads to your Downloads folder and opens, one drag from installed.
Is it affiliated with Apple?
No. Mac Duo is an independent project inspired by the iPhone Duo fold. iPhone, MacBook and macOS are trademarks of Apple Inc.
From the person who made this
Free, and made at 1 a.m.
Mac Duo started as a "how hard can it be" on a weeknight and turned into this. It's free, there's no pro version coming, and nothing in it phones home. If closing your MacBook became the best part of your day, a coffee keeps the next late night going.