Getting Started with ROSI

Install ROSI

Download ROSI 5 for your platform from the ROSI downloads page or the Microsoft Store. Official packages bundle yt-dlp and FFmpeg. Windows binaries are signed via Azure Artifact Signing.

Upgrading from ROSI 4

ROSI 4.4.0 and later can upgrade to ROSI 5 from inside the app. When ROSI 4 is up to date, its update check offers ROSI 5. Choose Upgrade to ROSI 5 to start. ROSI downloads ROSI 5 and verifies its signature. You confirm again before ROSI 4 closes. ROSI then installs ROSI 5, removes ROSI 4, and opens ROSI 5. On first launch, ROSI 5 imports your ROSI 4 settings, queue, lifetime stats, and download activity. Your ROSI 4 data folder is kept.

The in-app upgrade needs Windows 10 version 2004 (build 19041) or later, or macOS 26 or later. On other systems, the upgrade is not offered:

• Microsoft Store: The Store updates ROSI, so the in-app upgrade does not run.
• Linux: Download the ROSI 5 AppImage or Flatpak from the ROSI downloads page, then open it once to import your ROSI 4 data.
• macOS before 26: Download ROSI 5 from the ROSI downloads page, then open it once to import your ROSI 4 data.
• Windows before build 19041: ROSI 5 needs Windows 10 version 2004 or later, so ROSI 4 stays installed.

ROSI 4.3.2 and earlier do not include the in-app upgrade. Update ROSI 4 to 4.4.0 or later first.

If the in-app upgrade fails, ROSI 4 stays installed and your settings are unchanged. ROSI explains the failure the next time it opens. To try again, choose Settings > Check for Updates, or download ROSI 5 from the ROSI downloads page.

System requirements

• Windows: Windows 10 version 2004 (build 19041) or later, on x64 or ARM64. The Microsoft Edge WebView2 runtime installs automatically when missing.
• macOS: macOS 15 or later. The universal build runs on Intel and Apple silicon.
• Linux: x64 with WebKitGTK 4.1 (Ubuntu 24.04+, Debian 13+, Fedora 43+, or a compatible distribution). ROSI 5 publishes an AppImage and a Flatpak. DEB and RPM packages are no longer published, and Linux ARM64 is not supported in version 5.

First download

1. Open ROSI and paste a supported URL into the address bar, or drag and drop URLs directly into the queue textarea.
2. Select your desired Download Profile in Settings (Best video, Audio-only, or Custom quality presets).
3. Choose your download folder, or enable the Ask every time setting to select a destination on each run.
4. Press Ctrl/Cmd + Enter or click Download to start. Track progress in the queue section.

Queue and UI controls

• Collapsible Queue: You can expand or collapse the queue section using the arrow controls or arrow keys to save vertical screen space.
• Flat UI: Toggle between the standard UI and the Flat UI using the toggle switch located on the main sidebar.
• Close Confirmation: Active downloads trigger a confirmation prompt before closing to prevent accidental progress loss.

YouTube support (Deno)

On Windows, macOS, and Linux AppImage builds, ROSI uses Deno for full YouTube support. The setup wizard can check for Deno and install it with winget or Homebrew on Windows and macOS when available, or open the official instructions. On Linux, install Deno with your package manager or the official instructions, then restart ROSI. The Flatpak build includes its own JavaScript runtime, so it does not need Deno.

Browser cookies (when needed)

Some sites require cookies from your browser. Enable Hook into Web Browser in Settings and select a supported browser. See the Browser Cookies guide for platform details.

Updates

Direct ROSI packages check GitHub for new releases and download updates in-app. In Settings, choose the Auto, Stable, or Beta update channel. Microsoft Store updates are delivered through the Store. Flatpak builds notify you when an update is available but must be reinstalled from the release page.

Upstream proxy (optional)

If your network requires an HTTP proxy, set Upstream proxy in Settings to http://host:port. ROSI still checks every destination before using the proxy and blocks private network targets. HTTP proxies only, with no authentication.

Custom FFmpeg path

Official builds include FFmpeg binaries. If you are building from source or prefer your own binary, set a custom FFmpeg path in Settings to override the bundled copy.