Lightweight screen annotation tool (~1.5 MB) — press a hotkey (keyboard-first) to instantly draw, highlight, and annotate anywhere on your desktop.
Download Latest Release — pick the installer for your platform from the assets list.
Windows users can also install the Microsoft Store version with WinGet:
winget install --id 9N6623X973JV --source msstoreOfficial downloads are GitHub Releases and Microsoft Store. Third-party mirrors may be outdated or repackaged.
After launching, the app runs silently in the system tray with no window shown.
- Annotate anywhere — draw over any app, including the taskbar
- 8 tools — pen, highlighter, arrow, rectangle, ellipse, line, eraser, text
- Flexible toolbar — press Space to toggle, or enable always-on in Settings; compact panel with More to expand, undo, copy, and whiteboard actions in-panel; independent floating window with drawing / click-through toggles
- Click-through mode — interact with apps below while staying in the session; toggle via toolbar buttons, Ctrl+Shift+X (global), or X while drawing; disabled in whiteboard mode
- Full keyboard control — every action has a shortcut, no menus needed
- Preserve drawings — enable Keep after exit under Whiteboard & content to resume on re-enter
- Whiteboard mode — set default entry to whiteboard, or press W to toggle; content rules are in Whiteboard & content settings
- Whiteboard copy — copy the whiteboard as an image with Ctrl/Command + C
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Built with Rust + Canvas, MarkerOn has an installer of just ~1.5 MB and a minimal memory footprint — no background daemons, no bloat. It responds instantly to your hotkey and renders annotations at full frame rate while consuming nearly zero system resources.
On macOS, use Command (⌘) in place of Ctrl, and Option (⌥) in place of Alt.
| Action | Windows | macOS |
|---|---|---|
| Toggle annotation mode | Ctrl + Shift + D | Command + Shift + D |
| Clear all annotations | Ctrl + Shift + C | Command + Shift + C |
| Toggle click-through mode | Ctrl + Shift + X | Command + Shift + X |
| Key | Tool | Key | Tool |
|---|---|---|---|
| 1 | Pen | 5 | Ellipse |
| 2 | Highlighter | 6 | Line |
| 3 | Arrow | 7 | Eraser |
| 4 | Rectangle | T | Text |
| Action | Windows | macOS |
|---|---|---|
| Toolbar (toggle) | Space | Space |
| Click-through (while drawing) | X | X |
| Toolbar always-on / layout | Settings → General | Settings → General |
| Copy screen | Ctrl + C | Command + C |
| Whiteboard toggle | W | W |
| Undo / Redo | Ctrl + Z / Y | Command + Z / Y |
| Stroke width | Ctrl + Scroll | Command + Scroll (pen & shapes share; highlighter/eraser/text separate) |
| Clear all | Delete | Delete |
| Exit | Esc | Esc |
All shortcuts
| 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 |
| Action | Effect |
|---|---|
| Element dragging | In General settings: Off / Hover drag / Hold Ctrl to drag |
| 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 |
| Action | Effect |
|---|---|
| Q / E | Previous / Next color |
| Right-click | Open quick color picker at cursor |
| Action | Effect |
|---|---|
| W | Toggle whiteboard mode |
| Ctrl + C / Command + C | Copy the current whiteboard as an image |
| Settings | General → Whiteboard & content: default entry, keep after exit, keep on W toggle |
| Action | Windows | macOS |
|---|---|---|
| Stroke width | Ctrl + Scroll | Command + Scroll |
| Redo (alt) | Ctrl + Shift + Z | Command + Shift + Z |
| Switch window & exit | Alt + Tab | Command + Tab |
- Toolbar display — press Space to toggle, or always-on (Space does nothing when pinned); floating toolbar window with drawing / click-through buttons; use More to expand full options
- Click-through — pass mouse events to apps below; toggle in toolbar, with Ctrl+Shift+X or X (not in whiteboard mode)
- Whiteboard & content — default entry (screen / whiteboard), keep after exit, keep on W toggle
- Element dragging — off, hover to drag, or hold Ctrl/Command to drag (disabled while eraser is selected)
- Eraser mode — stroke (local erase) or object (delete whole elements when passing over); eraser tool disables element dragging
- Stroke width — Ctrl/Command + scroll or toolbar; pen & shapes share one width, highlighter/eraser/text are separate
- Angle snap step — snap interval for straight lines drawn with Alt
- Auto start — launch the app automatically at system startup
npm install
npm run dev
npm run build| 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/
│ │ ├── overlay.rs # Overlay session state, toolbar window, click-through
│ │ └── lib.rs # Rust backend — tray, shortcuts, IPC
│ └── tauri.conf.json # Tauri configuration
│
├── src/
│ ├── components/
│ │ ├── DrawingOverlay.vue # Drawing overlay (Canvas + interactions)
│ │ ├── ToolbarWindow.vue # Standalone toolbar window host
│ │ ├── ToolToolbar.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)
│ │ └── overlayBridge.ts # Cross-window overlay ↔ toolbar events
│ ├── 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