MarkerOn

Lightweight screen annotation tool — press a hotkey to instantly draw, highlight, and annotate anywhere on your desktop.

中文

Download

Download Latest Release — pick the installer for your platform from the assets list.

Features

• Annotate anywhere — draw over any app, including the taskbar
• 8 tools — pen, highlighter, arrow, rectangle, ellipse, line, eraser, text
• Intuitive panel — press Space to toggle tools, colors, and stroke widths
• Full keyboard control — every action has a shortcut, no menus needed

Keyboard Shortcuts

On macOS, use Command (⌘) in place of Ctrl, and Option (⌥) in place of Alt.

Global Shortcuts

Action	Windows	macOS
Toggle annotation mode	Ctrl + Shift + D	Command + Shift + D
Clear all annotations	Ctrl + Shift + C	Command + Shift + C

Tool Switching

Key	Tool	Key	Tool
1	Pen	5	Ellipse
2	Highlighter	6	Line
3	Arrow	7	Eraser
4	Rectangle	T	Text

Common Actions

Action	Windows	macOS
Settings panel	Space	Space
Copy screen	Ctrl + C	Command + C
Undo / Redo	Ctrl + Z / Y	Command + Z / Y
Stroke width	Ctrl + Scroll	Command + Scroll
Clear all	Delete	Delete
Exit	Esc	Esc

All shortcuts

Drawing with Modifier Keys

Draws	Windows	macOS
Current tool (default: pen)	Drag	Drag
Line	Alt + Drag	Option + Drag
Rectangle	Ctrl + Drag	Command + Drag
Square	Ctrl + Alt + Drag	Command + Option + Drag
Ellipse	Shift + Drag	Shift + Drag
Circle	Shift + Alt + Drag	Shift + Option + Drag
Arrow	Ctrl + Shift + Drag	Command + Shift + Drag

Edit & Move

Action	Effect
Hover over an element and drag	Move the element (enable "Allow dragging existing elements" in settings)
Double-click existing text	Re-enter edit mode for that text
Double-click empty area in T mode	Create a new text input at cursor position

Color Switching

Action	Effect
Q / E	Previous / Next color
Right-click	Open quick color picker at cursor

Other

Action	Windows	macOS
Stroke width	Ctrl + Scroll	Command + Scroll
Redo (alt)	Ctrl + Shift + Z	Command + Shift + Z
Switch window & exit	Alt + Tab	Command + Tab

Quick Start

npm install
npm run dev
npm run build

After launching, the app runs silently in the system tray with no window shown.

Tech Stack

Technology	Role
Tauri v2	Desktop framework — Rust backend, system tray, global shortcuts, transparent always-on-top window
Vue 3	Frontend UI framework
Vite	Fast bundling and HMR
TypeScript	Full type safety
Canvas API	High-performance drawing engine

Project structure

markeron/
├── src-tauri/
│   ├── src/
│   │   └── lib.rs               # Rust backend — window management, shortcuts, tray
│   └── tauri.conf.json          # Tauri configuration
│
├── src/
│   ├── components/
│   │   ├── DrawingOverlay.vue   # Drawing overlay (Canvas + interactions)
│   │   ├── SettingsPanel.vue    # Annotation toolbar (tool / color / stroke)
│   │   ├── SettingsView.vue     # Settings window (shortcut config / sidebar layout)
│   │   └── TextBox.vue          # Inline text input
│   ├── composables/
│   │   └── useDrawing.ts        # Drawing engine (pen, shapes, text, undo/redo)
│   ├── types/
│   │   └── app.d.ts             # TypeScript type declarations
│   ├── App.vue                  # Root component
│   ├── main.ts                  # Renderer entry point
│   └── style.css                # Global styles
│
├── index.html                   # HTML entry
├── vite.config.ts               # Vite configuration
└── package.json

License

MIT