Download, verify and install with confidence.

1. Use the official download

Download only from lemoaconnect.com. Choose the installer for normal desktop integration, or the portable ZIP when you prefer an extracted folder with no installation.

2. Verify the SHA-256 hash

Open PowerShell in the download folder and run:

The installer result must be:

For the portable ZIP, the SHA-256 value is:

If a value differs, do not open the file. Delete it and download a fresh copy from this website.

3. Install or extract

Installer

Open Lemoa-iperf3-Setup-1.0.0-x64.exe and follow the setup prompts. Windows may request administrator approval during installation.

Portable ZIP

Use Extract All, open the extracted LemoaIperf3 folder, and run LemoaIperf3.exe. Keep the _internal folder beside the executable.

4. Understand the Windows warning

5. Server firewall behavior

Client mode does not need an inbound firewall rule. When you start server mode, the app requests administrator approval to create a narrowly scoped temporary Windows Private-network rule for TCP or UDP port 5201. The app removes its tagged rule when the server stops; uninstall also removes installed rules.

Use server mode only on a trusted network. Do not expose port 5201 directly to the public internet unless you understand and intentionally control that access.

6. First test

1. Open Lemoa iperf3 on the server computer and select the correct interface.
2. Start server mode and note the displayed IPv4 address.
3. On the second device, open an iperf3 client and enter that address on port 5201.
4. Run TCP first, then use reverse, bidirectional or UDP only when the test requires them.
5. Interpret the result as path throughput between those two endpoints—not as an internet speed test.