A freeware guitar-practice app that plays Rocksmith-format .psarc charts from your own computer — your personal library stays on disk; the app never uploads it. Built around freeware CDLC from the CustomsForge community. Grant a local folder of your own CDLC to play. Optional curated demos load from our CDN only when you open Play with ?demo=songs (charts) or ?demo=stems (charts + stem mixes; larger download).

Play latest on web Play with demos Play with stems Get app Itch.io managed app

What it does

Point it at a folder of CDLC .psarc files on your disk and it renders the charts on a 3D highway with audio, practice speed control (pitch-preserving time stretch), per-arrangement tuning info, playlists and profiles.

Your files stay on disk

Charts live on your machine. In the browser, the app asks for read-only access to a local folder via the folder picker; .psarc bytes are read in the page and never uploaded. Saved state (profiles, playlists, scan cache) lives in your browser's local storage for this site.

Chromium required (web)

The browser build needs a Chromium-based browser (Chrome or Edge). Folder access uses the File System Access API (showDirectoryPicker), which Firefox and Safari do not support. The build also runs multithreaded WebAssembly (Emscripten pthreads via SharedArrayBuffer), which needs a cross-origin-isolated page — something the site sets up automatically, but Chromium is still the supported target for the full library flow.

What it is not

This project is not affiliated with Ubisoft or Rocksmith, and it does not host, distribute, or bypass official Rocksmith DLC. It reads chart files you already have. Support official releases and the artists who make the music.

Platforms

Play in the browser at /latest (Chromium required), or grab desktop builds for macOS (Apple Silicon and Intel) and Windows from the versions page or itch.io. Desktop builds read .psarc folders from disk without the browser folder API.