# fortio/fortio

Fortio load testing library, command line tool, advanced echo server and web UI in go (golang). Allows to specify a set query-per-second load and record latency histograms and other useful stats.

Repository: https://github.com/fortio/fortio
Canonical: https://ross.abutalabs.com/products/fortio
Homepage: https://fortio.org
Language: Go
License: Apache-2.0
License Family: permissive
Topics: golang, golang-library, golang-application, performance, performance-testing, performance-visualization, http, grpc, proxy, go, stress-testing
Last push: 2026-08-24T13:32:37+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 88, longevity 100
- inputs: {"age_days": 3250, "days_push": 9, "days_rel": 83, "gap_med": 13, "n_releases_24m": 26}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3722, forks 277 (observed 2026-08-28T04:08:15.532290+00:00)

## What it is
Fortio is a Go-based load testing library, CLI tool, and web UI originally built for Istio. It generates load at a specified queries-per-second rate and records latency histograms and percentiles, and also provides echo/debug server features for HTTP, gRPC, and TCP.

## Use cases
- load test an HTTP API at a fixed QPS and get p99 latency
- stress test a gRPC service
- measure latency histograms and percentiles for microservices
- run a fault-injection echo server that adds latency or errors
- compare performance of multiple runs graphically via web UI
- load test a service until interrupted at max speed

## When to choose
- you need precise QPS-controlled load generation with latency percentile stats
- you want a small, fast, embeddable Go load testing library
- you're testing Istio or other microservice meshes
- you need HTTP, gRPC, and TCP load testing in one tool

## When to avoid
- you need distributed load generation across many machines out of the box
- you need browser-level or scripted user-journey testing
- you prefer a GUI-first tool like JMeter or k6's ecosystem

## Facets
- artifact type: cli-tool
- maturity: stable
- function: benchmarking, http-client, testing, load-testing
- domain: developer-tools, performance, testing, microservices
- platform: go, windows, cli
- tags: load-testing, stress-testing, latency-histograms, grpc, echo-server, istio, web-ui, qps, linux, macos, docker, web-server

## Member repositories
- fortio/fortio (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:15.532290+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:29:18.630816+00:00, confidence not recorded.
  - readme: https://github.com/fortio/fortio (fetched 2026-08-28T04:08:15.532290+00:00, sha 2f131a81a888)
  - homepage: https://fortio.org (fetched 2026-08-29T09:23:55.200585+00:00, sha aaafec4d8b1e)
- Data as of 2026-08-30T08:39:29.467469+00:00.