SPV-2 - Side Panel Visualizer

Real-time audio visualizer in Chrome's side panel. Oscilloscope, spectrum, BPM & key detection for YouTube, Spotify & more.

Turn any music site into a studio-grade meter bridge. No matter your scene — mainstream streaming, indie, DJ, or live coding — SPV-2 has you covered. Works out of the box on 10+ music sites including YouTube, Spotify, SoundCloud, Beatport, and Strudel. Want to use SPV-2 on other sites? Enable "All websites" in Settings > Advanced. 🎵 What is SPV-2? SPV-2 is a Chrome extension that analyzes audio in real time and displays multiple instrument-style visualizations in Chrome's side panel. No installs, no DAW, no tab switching — just click and see the sound. 🎛️ Features • Oscilloscope — Waveform (W) and Lissajous (XY) modes with adjustable time/vertical scale and auto trigger • Spectrum Analyzer — 32-band logarithmic FFT with peak hold, segmented LED or solid bar styles • Chromagram — Polyphonic pitch class detection with piano-roll keyboard and Note Flow scrolling display • BPM Detection — Spectral flux onset detection with autocorrelation tempo estimation • Key Detection — Chroma-based key estimation with Camelot notation for DJs • Track Info — Track title, channel name, BPM, and key in one glance • 30+ Themes — Built-in palettes plus a curated set derived from Strudel's editor themes • Customizable Layout — Show/hide any panel, minimize sections, adjust settings per module 🎨 Themes Built for Every Mood SPV-2 ships with the original lineup — Default, Neon, Monochrome, Amber, Lemon, Phosphor, Ice, Sakura, Light and more — and adds a wide selection of palettes derived from the live-coding ecosystem (Dracula, Tokyo Night, Gruvbox, Nord, Solarized, and many more). Pick a look that matches your track, your stream, or your late-night listening session. 🟣 Live Coding & Algorave Friendly SPV-2 plays nicely with browser-based live coding environments. When you capture a Strudel tab, SPV-2 can auto-sync its visualizer theme to Strudel's current editor theme — your spectrum, oscilloscope and chromagram instantly match the colors on stage. One toggle, zero setup. If you're not a live coder, the new theme palettes alone make this update worth grabbing. 🔒 Zero Interference SPV-2 never touches the page. No content scripts, no DOM injection, no ads, no tracking. Audio is captured via Chrome's tabCapture API and processed entirely within the extension. 🎧 Built for Music Listeners Whether you're a DJ checking BPM and key during a live set, a producer analyzing frequency balance, a live coder watching your patterns light up the spectrum, or a curious listener who wants to see the music — SPV-2 gives you a studio-grade view without leaving your browser. ⚡ Technical Highlights • Manifest V3 compliant • Offscreen Document for audio processing • 30 fps real-time rendering • Automatic resource cleanup on panel close, tab close, or navigation away 🔑 Permissions Explained • tabCapture: Required to capture audio from the active tab • offscreen: Required for audio processing (Web Audio API) • sidePanel: Required to display the visualizer • storage: Required to save your settings and theme preference • tabs / activeTab: Required to identify whether the current tab is a supported site • scripting: Required only on Strudel to read the editor's theme name from the page's localStorage when Auto-sync is enabled • Host permissions: Required for each supported music site — SPV-2 only uses these to capture tab audio, no data is collected or sent 📋 What's New ### v1.3.2 — 2026-07-01 • Oscilloscope time axis calibrated to the real sample rate — the time scale (e.g. "20 ms/div") now reads true at 44.1 kHz playback instead of assuming 48 kHz • Spectrum analyzer — right-edge frequency label corrected from "20k" to "16k" to match the actual gridline frequency (gridline position unchanged) • Display-accuracy calibration only — no change to the underlying waveform, bar heights, or frequency/pitch axes ### v1.3.1 — 2026-06-15 • Spectrum analyzer — smoother low-frequency display; the low end now renders as a clean gradient down to 20 Hz instead of stepped, duplicated bars • Spanish (es) interface added ### v1.3.0 — 2026-06-01 • Japanese and German localization added ### v1.2.0 — 2026-05-01 • Auto-sync with Strudel — When capturing a Strudel tab, SPV-2 can match its visualizer theme to Strudel's current editor theme automatically • 30+ themes — A big jump in look-and-feel options, with new palettes derived from Strudel's editor themes (Dracula, Tokyo Night, Gruvbox, Nord, Solarized, and more) • Theme picker reorganized — Built-in and Strudel-derived themes are grouped in the dropdown for easier browsing • Light theme rendering — Tokyo Night Light, Solarized Light and other bright palettes now render with proper contrast • Various polish and stability improvements ### v1.1.0 — 2026-04-10 • Multi-site support — works on 10+ music sites including YouTube, Spotify, SoundCloud, Beatport, and Strudel • "All websites" mode — Enable in Settings > Advanced to use SPV-2 on any site with audio • Oscilloscope V Scale — x0.5 / x1 / x2 / x4 vertical zoom for both Waveform and XY modes • Bilingual confirmation modal before Chrome's permission dialog • Spectrum analyzer frequency label fix (16k → 20k) and button width stability improvements ### v1.0.0 — 2026-04-07 • Initial Chrome Web Store release with oscilloscope, spectrum analyzer, chromagram, BPM/key detection, and 10 built-in themes