Ketch

Project Overview

Ketch is a fast, open-source download manager with one engine covering macOS, Windows, Linux, Android, iOS, the web, the command line and browser extensions, letting your phone, laptop and home server view and control each other's downloads.

Every file is split across parallel connections shown as live speed lanes, and an embeddable Kotlin Multiplatform library is published on Maven Central for integrating the same engine into your own apps.

Item	Value
Platforms	macOS, Windows, Linux, Android 8.0+, iOS 18+, Web, CLI
Stack	Kotlin Multiplatform
Link types	HTTP(S), FTP, torrents and magnets
License	Apache-2.0

One download engine for every device you own, with parallel connections, multi-network spread and cross-device control.

Key Features

• Parallel connections: files download over split ranges with a live lane per connection, add or remove connections mid-download
• Multiple networks: spread one download over Wi-Fi, Ethernet and cellular data (Android)
• Proxies: system proxy or authenticated HTTP and SOCKS5 proxies, with exceptions and per-download overrides
• Pause and resume: continue after restarts, verify the server file is unchanged first, retry failed connections automatically
• Every link type: web direct links, FTP, torrents and magnets in one place
• Paired devices: link phones, laptops and home servers, control downloads from any of them
• Embeddable library: the KMP library on Maven Central brings parallel downloads, queues and speed limits
• Browser extension: takes over downloads in Chrome, Edge and Firefox

Target Audience

• Heavy downloaders switching between devices
• Users with a NAS or home server
• Users who need solid resume and queue management
• Developers embedding download capabilities into their apps

Quick Start

1. Grab the package for your platform from Releases: macOS DMG, Windows MSI or portable zip, Linux deb, Android APK
2. Open the app, paste a link or let the browser extension take over
3. Watch per-connection speeds on the connections page and tune them
4. Pair another device to view and control downloads remotely
5. Developers can add the Ketch library from Maven Central

Core Advantages

• Truly parallel: range-split downloads saturate multiple paths even for one file
• One engine everywhere: phones, desktops, servers and the CLI share the same kernel
• Device synergy: add a task once, every paired device sees and controls it
• Embedding friendly: the engine ships as a KMP library with low integration cost

System Requirements

Item	Requirement
Desktop	macOS (Apple Silicon, Intel), Windows x64/ARM64, Linux x64/ARM64
Mobile	Android 8.0+; iOS 18+ built from source with Xcode
Runtime	desktop apps bundle their runtime, CLI is a single native binary, no Java needed
Server	Docker image for x64 and ARM64 NAS devices

Notes

• Pre-1.0: the project is under active development, rough edges are expected and reports are welcome
• iOS self-build: no ready-made iOS package yet, build with Xcode
• Unfinished marker: in-progress files carry the .ketch suffix so partial files are never mistaken for complete ones