Cornerstack

Your screenshots, stacked in the corner of the screen until you've used them.
Free and open source, for macOS 14 Sonoma and later.

What it does

The macOS screenshot preview shows up for a few seconds and vanishes. Take three screenshots in a row and only the newest is still there to grab.

Cornerstack keeps them. Every capture lands in a stack in the bottom right corner, newest closest to the corner, and stays until you drag it somewhere or throw it away. Nothing times out.

Details

• Fast. A new capture flies from where you took it into the stack in a third of a second.
• Everywhere. The stack shows over full screen apps. You can turn that off in Settings.
• Out of the way. Clicks pass through everywhere except over a card, and the stack never shows up in your screenshots.
• Any size. Cards fit your screen automatically. Settings (menu bar icon › Settings…, or open the app again) has Small, Medium and Large, and a slider for anything in between.
• Your keys. Change ⌥ ⌘ C and ⌥ ⌘ T in Settings, or turn them off.
• Clean Desktop. Say yes to Handle screenshots on first launch and captures, screen recordings included, go to a folder of their own instead of piling up on the Desktop. They stay there for 30 days after they leave the stack (Open screenshots folder in the menu bar), then move to the Trash. Drag one anywhere to keep it for good. Your previous settings come back when you quit.
• Up to five. Once the stack is full, a new capture pushes out the oldest card you don't keep. Large cards on a small screen fit fewer than five. Its file stays where it is.
• Kept or put back. The pin in a card's top right corner keeps it. Drops into apps and Clear stack leave a kept card in place, new captures push the other cards out first, and it has no cross, so it can't go by accident. Put back last card in the menu bar restores the cards that left most recently, while their files still exist.
• Copied images too. Switch on Add copied images in Settings and images you copy join the stack. Only images: anything copied along with text or a file, and anything a password manager marks as private, is left alone.
• Text from images. Copy Text copies the text in a screenshot. Apple's Vision framework reads it on your Mac, without the internet.

How it compares

Tips

• With Add copied images on, ⌃ ⇧ ⌘ 4 gives you the image on the clipboard, a file and a card in one go.
• Drag a card into a terminal, or ⌥-click it and paste, to hand its path to command-line tools.
• Put back last card undoes an accidental cross or drop.
• The stack comes back after a restart.

Privacy and permissions

• No network, accounts or analytics. Your screenshots never leave your Mac.
• Text recognition runs on your Mac.
• The clipboard is only read while Add copied images is on.
• If your screenshots go to the Desktop, Documents or Downloads, macOS asks for access to that folder.

Not planned

• Capture modes or an annotation editor. Use CleanShot X or Shottr.
• A history, a library or a long stack. Five cards is the point.
• Clipboard-manager features.
• Cloud uploads or accounts.

Install

1. Download the .dmg from the latest release, open it and drag Cornerstack to Applications.
2. Open Cornerstack. It's free and open source but not notarized by Apple, so macOS says "Cornerstack" Not Opened. Click Done.
3. Open System Settings › Privacy & Security, scroll down to Security and click Open Anyway next to Cornerstack. Confirm with your password or Touch ID. You only do this once per version.

On macOS 14 Sonoma, right-click the app and choose Open instead. Or skip the prompts from Terminal:

xattr -dr com.apple.quarantine /Applications/Cornerstack.app

Rather not run a downloaded binary at all? Build it yourself, it takes a minute.

Build from source

git clone https://github.com/nemcaya/cornerstack.git
cd cornerstack
scripts/build-app.sh
open build/Cornerstack.app

You need the Swift toolchain; Xcode is optional. With the Command Line Tools for macOS 27, the script falls back to the macOS 26 SDK installed alongside them, because the newer SDK needs a SwiftUI macro plugin only Xcode ships. Local builds are signed ad hoc, so macOS asks for access to the Desktop again after each rebuild.

scripts/make-dmg.sh builds the disk image for a release. It needs uv to run dmgbuild.

Inside the app

Folder	File	Role
App	AppDelegate.swift	Menu bar, shortcuts, showing and hiding the stack
	FullScreen.swift	Knows when a full screen app is up
	Settings.swift	The Settings window
	HotKey.swift, ClosureMenuItem.swift, Localization.swift	Small helpers
Stack	Stack.swift	What is in the stack, and what you can do with each card
	StackPanel.swift	The transparent column along the right edge of the screen
	StackView.swift, ShotView.swift, Layout.swift	The stack and its cards
	GrabArea.swift	Click, long press, drag and drop
	CaptureFlight.swift	The flight of a new capture, and the fall of a discarded one
	Thumbnail.swift	Decodes each capture once, for its card and its flight
Intake	ScreenshotWatcher.swift	Notices new screenshots
	ClipboardWatcher.swift	Notices images copied to the clipboard
	Inbox.swift	Takes over the screenshot settings and puts them back
Editors	Markup.swift, Trim.swift	Markup for screenshots, trimming for recordings
	QuickLook.swift	Quick Look
	TextRecognition.swift	Text recognition for Copy Text

Text lives in Sources/Cornerstack/Resources/<language>.lproj. To add a language, copy en.lproj, translate the values and run swift scripts/check-strings.swift. The icon is drawn in code by scripts/make-icon.swift.

Why this exists

Seeing BridgeShot, the screenshot app by BridgeMind, made me want one of my own. It came with their paid plans, so I made a free, open source one instead.

Cornerstack began as a fork of Tendedero by Alejandro Buján, a lovely app that hangs your screenshots on a line under the menu bar. I wanted the same idea in the place macOS already puts its own screenshot preview, so I reworked how it looks and behaves:

• a stack in the bottom right corner instead of a line along the top, with the newest capture nearest the corner;
• no menu bar reveal and no auto-hide: the stack stays until you deal with every capture;
• dragging a capture into an app removes it from the stack, since you rarely need it twice;
• a fix for drags that never report their end, which could freeze the stack;
• shown over full screen apps and left out of new screenshots, with a faster flight animation.

The original idea and most of the groundwork are Alejandro's. If you prefer the line, use Tendedero.

License

MIT, including Alejandro Buján's original work. The Tendedero name and icon are not covered by it and are not used here, see NOTICE. Cornerstack is an independent project and is not affiliated with Tendedero.