Apache JMeter vs Fortio

Apache JMeter is a free, open-source Java application for testing functional behavior under load and measuring performance. It can simulate heavy workloads on servers, networks and other systems. Supported test types include HTTP and HTTPS, SOAP and REST, FTP, JDBC, LDAP, JMS, email protocols, TCP, Java objects, and native commands or shell scripts. Its test IDE can record plans from browsers or native applications, then help users build and debug them. JMeter provides command-line operation on Java-compatible systems and can generate dynamic HTML reports. It also supports remote testing, pluggable samplers and timers, scripting such as Groovy and BeanShell, and plugins for analysis and visualization. Third-party open-source libraries connect it to Maven, Gradle and Jenkins for continuous integration. JMeter works at the protocol level: it does not execute JavaScript in pages or render them as a browser does. It requires Java 8 or later. The project recommends command-line rather than GUI operation for load testing and advises caution with untrusted JMX files, which may execute code when opened.

Fortio is a free, open-source Go project for HTTP and gRPC load testing. It combines a load-testing library, command-line tool, echo server, and web interface, with API, Linux, macOS, self-hosted, web, and Windows platforms. A run can target a specified queries-per-second rate or maximum speed, and can stop after a duration, a fixed call count, or interruption. Fortio records latency histograms and percentiles such as p99. Its server offers a web UI and REST API for starting tests and viewing latency and comparison graphs. Additional server functions include request echo, probabilistic latency or error injection, TCP echo and proxy, HTTP fan-out proxy, and gRPC echo and health. Go applications can embed Fortio or use its log, stats, and fhttp components separately. Fortiotel adds OpenTelemetry hooks. Fortio Proxy can provide HTTPS with automatic certificates and multiplex gRPC and HTTP behind one port. Installation options include Docker, Go, binaries, Homebrew, and a Windows ZIP.