Hydra Download Manager
Hydra Download Manager is an open-source, high-performance download accelerator for Windows, macOS, and Linux. It combines a multi-source download engine with a native desktop interface, a scriptable command-line tool, an interactive terminal queue manager, and official browser integration for Chrome, Edge, Firefox, and Safari. The project is aimed at developers, power users, and teams who need reliable, fast transfers across many files, mirrors, and environments.
The core engine, packaged as libhydra with a stable C ABI, drains multiple mirrors and parallel HTTP, HTTPS, and FTP streams at once. It uses adaptive concurrency to ramp up per server, dynamic range stealing to reclaim byte ranges from lagging connections, and statistical stall prediction to flag collapsing connections before standard socket timeouts fire. End-to-end integrity is supported through per-chunk checksum manifests, Content-MD5 validation, and local Reed-Solomon erasure coding. Polyglot bindings and examples are available for C, C++, Python, Swift, Go, Kotlin, Dart, C#, and Zig, with pre-packaged Android jniLibs and an Apple Hydra.xcframework for mobile embedding.
The desktop application wraps the engine in a localized GUI with queues and scheduling, clipboard watching, speed limits and connection caps, category-based auto-sorting, power save mode, and system tray behavior. The CLI and TUI share the same engine, offering wget and curl compatibility personalities, remote checksum lookup, and an interactive queue manager for servers, containers, and terminal-first workflows. Browser extensions hand downloads to the desktop app over a local WebSocket bridge with a native-messaging fallback.
Hydra fits best as a self-hostable alternative to classic download managers such as IDM, FDM, and JDownloader, and as an embeddable acceleration layer for applications that need multi-source, resumable, integrity-checked transfers. It is distributed freely as open-source software, with installers and packages for Windows, Linux, and macOS, plus package manager support through Homebrew, Winget, Ubuntu PPA, Fedora COPR, and Arch AUR.