Spitfire is a self-hosted load testing and performance monitoring tool that runs on your own servers (Docker or Kubernetes, amd64 and arm64). Build tests in the browser like a form, no scripting needed, or import OpenAPI, Postman, HAR, k6 or JMeter. One test can mix HTTP, gRPC, WebSocket, Kafka, MQTT, SQL and real browser users.
The same test works in two modes. Watch: critical flows run against production every 1-60 minutes at a low load, with uptime, drift detection, SLOs with error budgets and a status page. Heavy load when needed: a distributed load test that climbs in stages and stops at the breaking point, showing what slowed down in the backend (OpenTelemetry, Datadog, New Relic, Dynatrace, Zabbix, Instana).
Also: A/B version comparison with a CI release gate, multi-location runners that dial out (no inbound ports), production write guard, SSO/SCIM, audit log, offline license that works air-gapped. Free edition with no expiry.
