Helix is a modern, blazing fast, multi-threaded desktop download manager built with C# (.NET 8) and WPF. It features a stunning Fluent design, deep browser integration via a companion extension, and robust network engines (HTTP/HLS/Torrents/YouTube) tuned for maximum speed and minimal memory footprint.
- 🚀 Multi-threaded Downloads: Splits files into multiple chunks and downloads them in parallel, saturating your internet bandwidth for maximum speed.
- 🔗 BitTorrent & Magnet Links: Native support for downloading torrents and magnet links directly within the app via a fully integrated
TorrentEngine. - 📹 YouTube & Video Extracting: Built-in
yt-dlpintegration to easily parse and download formats from YouTube and hundreds of other media sites. - 🎥 Secure HLS (m3u8) Downloader: Downloads adaptive streams safely, validating all segment downloads before merging to prevent corrupted output videos.
- ⚡ Insanely Optimized UI: The Dashboard features full UI Virtualization, O(1) concurrent data structure lookups, and debounced events ensuring 60fps scrolling even with thousands of downloads.
- 🔄 Auto Theme Synchronization: Seamlessly inherits your Windows light/dark mode preference or lets you choose manual overrides.
- 📊 Real-time Sorting & Analytics: Organize and sort downloads dynamically by Name, Size, Status, or Date Added. Animated sparklines provide visual speed telemetry.
- 📁 Smart Auto-Categorization: Automatically sorts completed downloads into dedicated folders (Videos, Music, Documents, Archives, Programs, Code, etc.) based on file type.
- 🌐 Browser Extension Integration: Instantly captures browser downloads via a companion Chrome/Edge manifest v3 extension communicating over a secure localhost WebSocket.
- 🔒 Secure Credentials: Protects cookie credentials using Windows DPAPI encryption.
- 📦 Custom C# Installer: Features a beautiful, custom-built WPF installer with seamless browser extension deployment.
- Operating System: Windows 10 / Windows 11 (x64)
- Framework: .NET 8.0 SDK (to build)
- (Optional)
yt-dlpexecutable placed in the PATH or the app directory for YouTube support.
Use the provided PowerShell script build.ps1 or build using the standard .NET CLI:
# Restore & build debug configuration
dotnet build Helix.slnTo publish production-ready, self-contained binaries to the publish folder, run:
# Publishes WPF App, Browser Extension, and assets
powershell -File .\build.ps1 -PublishTo build the standalone installer, run the PowerShell script:
.\build-installer.ps1The final installer executable will be generated at Release\Helix_Installer.exe.
To enable integration with Google Chrome, Microsoft Edge, or other Chromium-based browsers:
- Open your browser and navigate to
chrome://extensionsoredge://extensions. - Enable Developer Mode (toggle in the top-right corner).
- Click Load unpacked and select the
helix-extensionfolder in the project root (or the published version atpublish\Helix-extension). - The extension will automatically connect to the Helix desktop host using a secure, rotating token generated on app startup.
Ctrl + N— Open new download dialogCtrl + F— Focus search boxDelete— Delete selected download from listCtrl + S— Open settings page
Helix.Core: The high-performance core engine handling segmented HTTP downloads, HLS stream merging, torrent downloading (TorrentEngine),yt-dlppiping, file scheduling, and local DB serialization.Helix.ModernUi: The WPF client interface featuring an MVVM pattern, Fluent styling, UI virtualization, tray integration, and background WebSocket service.Helix.Core.Tests: Unit tests verifying download scheduling, auto-categorization, and file conflict handling.Helix.Installer: Custom GUI deployment tool.helix-extension: Manifest V3 browser companion extension.