iPerf2 vs iperf3

iPerf2 measures network traffic performance, including throughput, latency, link capacity, and responsiveness. Testing uses a client to send traffic to a server. It can generate TCP and UDP traffic in one-way, bidirectional, full-duplex, and simultaneous multi-stream configurations. Measurements include one-way delay, round-trip time, jitter, packet loss, and throughput. It supports IPv4, IPv6, and multicast, including source-specific multicast joins, and reports can include enhanced metrics or use CSV format. The project manual describes an Android client with live meters for throughput, latency, and congestion signals. The manual also describes permit-key HMAC authentication using a timestamped HMAC-SHA256 value, with replay limited by a configurable time window. Its Professional feature set includes server access gating and remotely enabled server-side latency histograms. Measurements happen at socket-level reads and writes, so lower-level protocol-header overhead is excluded. iPerf2 and iPerf3 are separate implementations and do not interoperate. It runs on Android, Linux, macOS, and Windows, and can be self-hosted. Both listed editions are free.

iperf3 is a free command-line network measurement tool that reports achievable IP-network bandwidth, throughput, loss, and related results. It includes client and server functions for TCP, UDP, and SCTP tests, with adjustable timing, protocol, and buffer settings. Client or server output can be emitted as JSON, including line-delimited JSON for real-time parsing, and a library version can be embedded in other programs. The project uses a three-clause BSD license and lists Ubuntu Linux, FreeBSD, and macOS as its officially supported platforms. Windows is not officially supported; its FAQ points users with Windows problems toward iperf2. ESnet supplies source distributions rather than binary packages and recommends checking SHA256 checksums. iperf3 began as a perfSONAR bandwidth tester, its primary user base. It is not backwards compatible with the original iperf. Version 3.22 was released September 29, 2026.