Introduction

MacGet is a download manager for macOS Tahoe, written in SwiftUI with an actor-based engine. It splits each file across up to 16 HTTP-Range connections, learns how much parallelism each host will actually tolerate, and resumes cleanly across restarts.

These docs cover the shipping release, v1.3.0.

Why it exists

Most "multi-threaded" download managers open as many connections as you allow and treat the result as a win. Modern CDNs disagree: they reset connections after a few bytes, throttle the IP, or return 403. Past a certain point, more threads make a download slower, or make it fail outright.

MacGet treats parallelism as something to discover rather than assume. It probes upward while throughput improves, backs off when a host starts pushing back, and remembers what it learned so the next download from that origin starts at a sensible level.

Where to start

What's in the box

• Up to 16 parallel chunks per file, with work-stealing so one slow piece doesn't hold up the rest.
• Adaptive concurrency that scales up while it helps and demotes when the host objects, with the learned cap persisted per host.
• Resume across restarts, guarded by If-Range validators.
• Media downloads through a bundled yt-dlp and ffmpeg, opt-in.
• Authenticated downloads with credentials in the macOS Keychain.
• Browser capture for Chrome, Edge, Brave, and Firefox.
• Checksum verification before a partial file is promoted.
• Bandwidth limits, priorities, proxies, and auto-sorting into category folders.

A note on distribution

MacGet is free and distributed un-notarized, because notarization requires a paid Apple Developer account. macOS will warn you once on first launch. The first launch guide explains what the warning means and how to get past it — and why auto-updates are still signature-verified regardless.