Hysen LabsQuantum-Leap
A native macOS SSH-powered iperf3 client with real-time TCP/UDP bandwidth visualization.
A native macOS iperf3 client with live bandwidth charts
Quantum Leap is a desktop network performance workbench for macOS, Windows, and Linux that orchestrates iperf3 over SSH and shows real time throughput, jitter, and loss.
Test topologies
Quantum Leap supports more than one way to run a bandwidth test. A local test measures the link between your computer and a remote server, either by letting the app manage a temporary iperf3 service over SSH or by connecting to an existing iperf3 server. A device to device mode coordinates a direct test between two remote endpoints while your computer only orchestrates and displays the result. In device to device mode each endpoint has its own SSH credentials, bind addresses, and an optional custom iperf3 path, and the endpoints can be swapped with a single action. Temporary remote processes are cleaned up when a test stops, fails, or changes mode.
Live measurements and controls
The workspace draws live bandwidth curves and reports average and peak throughput, transfer totals, round trip time, jitter, packet loss, and TCP retransmissions. Test controls include a choice of TCP or UDP, upload or download direction, an optional total target bitrate, between 1 and 32 parallel streams, and either timed or continuous operation. The standard profile runs TCP with 8 streams, testing upload and download for 10 seconds each, while advanced mode allows 3 to 120 seconds or continuous runs. Per endpoint IPv4 or IPv6 binding and custom remote iperf3 paths are also supported.
Security and packaging
SSH passwords and private key passphrases are never written to logs or ordinary configuration files, and saved credentials are stored in the macOS Keychain, Windows Credential Manager, or a Linux Secret Service provider. When an SSH host key changes, the app shows its SHA-256 fingerprint and asks for explicit confirmation before connecting. The project is distributed under the GNU General Public License v3.0 only and provides builds for macOS 13 or later, Windows 10 and 11, and Linux x64 or ARM64, with a bundled iperf3 sidecar used by default on Windows and Linux.
Editorial conclusion
Quantum Leap is released under the GPL-3.0-only license and offers signed in app updates on macOS and Linux, while the public macOS build is ad hoc signed rather than notarized with an Apple Developer ID.
Community notes