Fortio vs Gatling

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.

Gatling is a load-testing and performance engineering platform for simulating traffic and finding performance bottlenecks. Tests can be written in code, generated with a no-code tool or imported from Postman. Scenarios support Java, JavaScript, TypeScript, Scala and Kotlin. The load engine supports HTTP out of the box and JMS, and can be extended for other protocols. The listing includes API and stress testing, distributed load and hybrid deployment; browser-based testing is marked unsupported. Gatling Studio is a native application that runs locally on macOS, Windows and Linux. Enterprise Edition adds a web interface for managing and monitoring tests, live dashboards, CI/CD integration, advanced permissions and hybrid or cloud deployment. Listed integrations include GitHub Actions, Jenkins, GitLab CI, Azure DevOps, Datadog, Dynatrace, New Relic, Slack and Microsoft Teams. Gatling says it is SOC 2 Type II certified and encrypts traffic in transit and stored data at rest. A free plan is available. Basic (annual) is €89 a year, billed annually; Enterprise has a free 14-day trial without a credit card.