MacDL

Simple network stress test tool.

MacDL is a small macOS utility for stress-testing an internet connection by repeatedly downloading a URL to memory and discarding the data.

What it does

• Downloads a supplied HTTP or HTTPS URL in a continuous loop.
• Shows current speed, total downloaded data, completed loops, active thread count, and the resolved server IP.
• Supports multiple download threads when the server correctly supports HTTP byte ranges.
• Detects stalled transfers and restarts automatically.
• Holds a macOS no-idle-sleep power assertion while a test is running so the test can continue in the background while the app remains open.

Usage

1. Open MacDL.
2. Paste a direct URL to a large file.
3. Choose the number of threads and stall timeout.
4. Press Start.
5. Press Stop before closing the window.

The app is intended for personal connection testing. It can use significant bandwidth and may affect data caps or other users on the same network.

Building

Build a release app with Xcode:

xcodebuild -project MacDL.xcodeproj -scheme MacDL -configuration Release -derivedDataPath .build/XcodeDerived CODE_SIGNING_ALLOWED=NO build

The built app will be at:

.build/XcodeDerived/Build/Products/Release/MacDL.app