A piano keyboard on your screen that lights up when you play. Made for music teachers, students, and content creators.
- 🎹 MIDI input — connect your digital piano or MIDI keyboard and see which keys you press in real time; devices are detected automatically when plugged in
- 🖱️ Mouse support — click on any key to highlight it, drag across keys to glide
- ✏️ Pencil tool — press P or toggle the pencil tool to start marking keys; left-click to mark, right-click to erase, press Esc to exit
- 🔠 Key labels — show or hide note names, octave numbers, sharps and flats
- 👇 Show on press — only show labels on keys that you are currently pressing
- 🎨 Custom colors — pick any highlight color; text adjusts automatically so it's always easy to read
- 🎶 Velocity sensitivity — optionally show how hard you press each key (brighter = harder); off by default
- 🎵 Sustain indicator — the pedal icon lights up when your MIDI sustain pedal is held
- 🔌 Auto-detect — if you have one MIDI device, the app connects to it automatically; virtual ports are ignored
- 📷 Save as image — click the camera button to save the keyboard as a PNG; right-click to quick save to your Pictures folder
- 🌍 7 languages — English, Deutsch, Español, Français, Polski, Português, Русский, Українська — switch in Settings, applies instantly
- 🔊 Built-in sound — optional test tones so you can hear what you press; off by default, enable in Settings
↔️ Octave range — use the + and − buttons to show more or fewer octaves (from A0 up to C8)- ⌨️ Computer keyboard — use your computer keyboard as a piano (A–K = one octave, Z/X = shift octave); toggle with Caps Lock or in Settings (on macOS, Caps Lock delivery can be unreliable — use the Settings checkbox if the shortcut doesn't respond)
- 🔧 UI scaling — make buttons and margins bigger or smaller (50–200%) — changes apply instantly
Default look
Arch Blue, 2 octaves, showing sharps, velocity brightness on
Red, pencil tool active, 4 octaves, flats, labels only on pressed keys
Teal, 1 octave, both sharps and flats, velocity brightness on
MIDI device, highlight color, UI scale, key labels, velocity, and update checker
Go to Releases and download the app for your system. No installation needed — just download and run.
- Download WIN_PianoMIDIViewer.exe
- Double-click the file to open it
If Windows shows a "Windows protected your PC" warning, click More info → Run anyway. This happens because the app is not signed with a Microsoft certificate — but it is still safe to run.
- Download MAC_PianoMIDIViewer.dmg
- Double-click to open the disk image
- Drag PianoMIDIViewer.app to the Applications folder
- Open Terminal (press
Cmd + Space, typeTerminal, press Enter) - Paste this command and press Enter:
xattr -cr /Applications/PianoMIDIViewer.app - Open PianoMIDIViewer from your Applications folder
Step 5 is needed because the app is not signed with an Apple certificate — but it is still safe to run. You only need to do this once.
- Download LINUX_PianoMIDIViewer.AppImage
- Right-click the file → Properties → Permissions → check "Allow executing as program"
- Double-click the file to open it
Or if you prefer the terminal:
chmod +x LINUX_PianoMIDIViewer.AppImage
./LINUX_PianoMIDIViewer.AppImageAlternative: Run from source (for power users)
Requires Python 3.8+:
git clone https://codeberg.org/skoomabwoy/piano-midi-viewer.git
cd piano-midi-viewer
python -m venv .venv
source .venv/bin/activate
pip install -e .
python piano_viewer.py| Architecture | piano_viewer/ package (11 focused modules) |
| Framework | PyQt6, python-rtmidi |
| Font | JetBrains Mono (embedded) |
| MIDI range | A0–C8 (notes 21–108) |
| Polling | 10ms (100Hz) |
See releases for full history.
9.4.0 — Re-voiced built-in sound (clear on any speaker, seamless across the keyboard), smoother window resizing on all platforms, HiDPI-sharp icons, more reliable MIDI hot-plug, safer settings file 9.3.0 — Computer keyboard input, custom pencil/eraser cursors, new app icon, AppImage sound fix (Fedora, Mint, Ubuntu) 9.2.0 — Live UI scaling and language switching (no restart needed), professional pedal icon, pencil tool marks out-of-range MIDI notes 9.1.1 — Phosphor icons for all buttons, MIDI auto-select, package refactor 9.1.0 — Built-in sound: optional test tones with sustain pedal support, velocity sensitivity, and redesigned app icon 9.0.0 — 7 languages: Deutsch, Español, Français, Polski, Português, Русский, Українська — select in Settings, app restarts in the new language 8.6.3 — Font fix for all platforms, macOS button styling, AppImage restart and portability fixes, CI smoke test 8.6.2 — Fix links not opening in browser from AppImage 8.6.1 — Fixed crash on corrupted settings, per-value recovery, camera icon, quick save subfolder 8.6.0 — Save keyboard as PNG (file dialog + quick save), error reporting dialog with copy-to-clipboard 8.5.3 — Test suite: 67 pytest tests covering all helper functions 8.5.2 — Trimmed CLAUDE.md, added CHANGELOG.md, pinned dependencies, committed SVG assets, git hook for dual-remote push 8.5.1 — Logging, settings migration framework, expanded comments, project folder reorganization 8.5.0 — New app icon, Linux AppImage format, macOS update checker fix, install instructions in DMG 8.4.0 — Velocity visualization: keys light up brighter the harder you press them (off by default in Settings) 8.3.0 — MIDI connection hardening: persistent scanner (no ALSA leaks), non-modal Settings, dropdown auto-refresh 8.2.2 — Fixed restart button in compiled builds (PyInstaller) 8.2.1 — MIDI hot-plug detection, auto-reconnect, version display and update checker in Settings 8.1.2 — UI scaling (25–200%), P shortcut for pencil tool 8.1.1 — S button is now a pure indicator (no visual feedback when clicked) 8.1.0 — Notes highlight only while actively pressed; S button is now a sustain pedal indicator only; pencil tool out-of-range marks now glow the + buttons 8.0.0 — UX rework: pencil tool, custom drawn cursors (pencil + eraser) 7.0.0 — Drawing/Playing modes, Mode button with sustain control 6.3.5 — macOS docs fix (xattr command for Gatekeeper) 6.3.4 — macOS support, dynamic key gaps, cross-platform fixes 6.3.3 — Adaptive button text color (matches note name behavior) 6.3.2 — OBS integration (octave range & window geometry persistence, visual polish) 6.3.1 — Cross-platform UI consistency (SVG icons, JetBrains Mono buttons) 6.3.0 — Linux standalone app (no Python required) 6.2.0 — Windows standalone .exe 6.1.0 — Show labels only when pressed 6.0.0 — Key labels (note names, octaves, accidentals) 5.0.0 — Mouse support, sustain modes
GPL-3.0 — See LICENSE
See CLAUDE.md for architecture docs.
Contributions welcome.