iperf
Measure maximum network bandwidth and performance.
Open the official app on iperf.fr
This tool is hosted by its maintainers. Click below to open iperf.fr in a new tab — it's their official demo.
Browse network tools →What's next with iperf?
Choose how you want to get started.
Use it free
Open the official tool or demo — no account needed.
Self-host it
Run the open-source version on your own infrastructure.
What is iperf?
iPerf3 is an open-source network bandwidth measurement tool designed to actively assess the maximum achievable throughput on IP networks. Developed by ESnet and Lawrence Berkeley National Laboratory, it supports TCP, UDP, and SCTP protocols over IPv4 and IPv6. The tool enables users to measure critical metrics such as bandwidth, packet loss, jitter, and latency, making it essential for network performance analysis and troubleshooting. Its primary purpose is to identify bottlenecks and validate network configurations by simulating traffic under controlled conditions. iPerf3 is widely used by network engineers, system administrators, and researchers to evaluate the performance of LANs, WANs, and cloud infrastructure. By providing detailed reports on data transfer rates and protocol-specific statistics, it helps ensure optimal network design and reliability. The tool's cross-platform compatibility, including support for Windows, Linux, macOS, and embedded systems, further enhances its utility in diverse environments.
How it works
How iperf works — see the article below for details on this network tools tool.
How to use it
- 1Use the iperf tool to complete your task.
- 2Use the iperf tool to complete your task.
- 3Use the iperf tool to complete your task.
- 4Use the iperf tool to complete your task.
What it can do
- network throughput
Use cases
Assumptions and limitations
Assumptions
- source: https://github.com/esnet/iperf
- license: BSD-3-Clause — free to use
- privacy: Self-hosted — you control your data
Limitations
- Self-hosted — requires setup, maintenance, and your own infrastructure.
- Relies on an external source (github.com); availability depends on that service.
- Focused on the network tools category: Measure maximum network bandwidth and performance..
Understanding the result
Measure maximum network bandwidth and performance.
Tool details
- Clearly flagged when a network request is needed.
- No account, no sign-up, and no tracking of your content.
- Powered by (BSD-3-Clause).
- Built with
- (esnet/iperf)
- License
- BSD-3-Clause
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with esnet/iperf. OpenToolVault provides the discovery and browser interface while crediting the original project maintainers.
- Built with
- License
- BSD-3-Clause
Open-source project
OpenToolVault is an independent directory. We are not affiliated with or endorsed by this project.
References
- / — GitHub Repository
Upstream project · GitHub
- BSD-3-Clause License
Upstream project
Frequently asked
What is iPerf3 and what does it do?
iPerf3 is a network testing tool that measures the maximum bandwidth of IP networks using TCP, UDP, and SCTP protocols. It provides insights into network performance by simulating traffic and reporting metrics like bandwidth, packet loss, and latency. Developed by ESnet and Lawrence Berkeley National Laboratory, it is used to diagnose network issues, validate configurations, and optimize data transfer rates. Its ability to run on multiple platforms and support advanced protocols makes it a standard tool for network analysis.
How does iPerf3 work technically?
iPerf3 operates by establishing a server-client connection where the server generates traffic and the client measures performance. It uses active measurements, sending data packets and analyzing responses to calculate bandwidth and latency. The tool allows tuning parameters like buffer sizes, packet rates, and connection counts to simulate real-world conditions. It supports features such as multicast testing, multiple simultaneous connections, and periodic reporting of metrics. By leveraging TCP window sizing, UDP stream control, and SCTP reliability, it provides comprehensive network diagnostics.
How do I run a basic bandwidth test with iPerf3?
To run a test, first install iPerf3 on both the server and client machines (e.g., via 'sudo apt-get install iperf3' on Linux). On the server, start the service with 'iperf3 -s'. On the client, initiate the test using 'iperf3 -c <server_ip> -t 30' to measure bandwidth over 30 seconds. Use '-i 5' for intermediate reports every 5 seconds. For UDP tests, add '-u' to the client command. Adjust parameters like '-P' for parallel connections or '-b' to specify target bandwidth.
How does iPerf3 compare to alternatives like iperf2 or JMeter?
iPerf3 differs from iperf2 by being a complete rewrite with improved protocol support (SCTP) and enhanced features like multicast and multi-connection handling. Compared to JMeter, iPerf3 is simpler for raw bandwidth testing but lacks advanced application-level scripting. Tools like iperf2 (older TCP-only) and Netperf (focused on latency) offer narrower capabilities. iPerf3's cross-platform support and real-time metrics make it preferable for quick network validation, while JMeter suits complex application simulations.
What should I do if I get 'No route to host' errors?
This error typically indicates a firewall blocking the connection or incorrect server IP. Verify the server's IP address with 'iperf3 -s' running and ensure ports 5201 (default) are open. Check firewall rules on both machines using 'ufw status' (Linux) or Windows Firewall settings. If the server is on a different network, use '-B <interface>' to bind to the correct subnet. Confirm network connectivity with 'ping <server_ip>' and adjust routing tables if necessary.