A free, open-source audio visualizer and meter rack for your desktop and your DAW.
Prism taps into your system audio and runs it through a rack of real-time scopes and meters. It grew out of the visualization engine in [Astra](https://github.com/Boof2015/astra), rebuilt as a standalone tool. Whether you're mixing a track, tuning a room, or just like watching your music, Prism gives you a window into what you're hearing.
## Scopes
Seven visualizers driven by a native C++ analysis engine:
- **Spectrum Analyzer** — FFT frequency display with heatmap and fill modes, configurable FFT size, spectral tilt, and log or linear scaling
- **Oscilloscope** — Time-domain waveform with a pitch-lock mode that syncs the display to the fundamental frequency
- **Vectorscope** — Stereo phase visualization in five display modes (Lissajous, polar, linear) with optional multiband RGB split
- **Spectrogram** — Scrolling frequency-over-time display with mel, log, and linear scale modes
- **VU Meter** — Classic loudness metering in needle or bar style, horizontal or vertical
- **Loudness Meter** — Compact LUFS metering following ITU-R BS.1770 with fast stereo peak activity
- **Waveform** — Scrolling time-domain view with mono, stereo, and multiband modes
Every scope is independently configurable. Drag and resize them into whatever layout makes sense, pop any scope out into its own window, and pin windows on top so they stay visible while you work.
## DAW Plugins
Every Prism scope also ships as a DAW plugin. Drop a **Spectrum**, **Oscilloscope**, **Vectorscope**, **Spectrogram**, **VU Meter**, **Loudness Meter**, or **Waveform** onto any track and it analyzes that track's audio in real time, the same analysis engine and the same interface as the desktop app.
- **VST3** on Windows, macOS, and Linux, plus **AU** on macOS.
- Each instance is fully configurable, and its settings save with your project.
- Plugins follow your active Prism theme and profile, so they match the desktop app out of the box.
- Audio passes through untouched. No DSP runs on the realtime audio thread.
Tested in Ableton Live, FL Studio, and Reaper. The plugins install alongside the desktop app, so there's no separate download.
## Audio Capture
Prism pulls audio at the OS level, straight from CoreAudio on macOS, WASAPI on Windows, or PulseAudio on Linux. No virtual cables or routing hacks. Flip on device input mode when you want to analyze a mic or a line-in instead.
Capture-to-display latency measures under 8ms. When tested at 120fps, measured latency was 0ms. What you see is what you hear.
## Terminal UI
Installable Prism packages also provide `prism-tui`, a native terminal frontend
for the shared C++ capture and analysis engine. It shows a responsive spectrum,
stereo VU meters, and momentary, short-term, and integrated LUFS readings.
```bash
prism-tui # Capture the default system output
prism-tui --list-devices # Print output device IDs; no TTY required
prism-tui --device