bombardier — Fast Cross-Platform HTTP Benchmarking Tool

Introduction

bombardier is a fast cross-platform HTTP benchmarking tool written in Go. It saturates a target URL with configurable concurrency and duration, then reports throughput, latency percentiles, and error rates in a clean terminal output.

What bombardier Does

• Generates high-concurrency HTTP load with minimal client-side overhead
• Supports both duration-based and request-count-based benchmarks
• Reports latency percentiles (p50, p75, p90, p95, p99) and average RPS
• Handles HTTP/1.1 and HTTP/2 connections
• Prints a real-time progress bar with live throughput during the test

Architecture Overview

bombardier spawns a pool of goroutines, each maintaining a persistent HTTP connection to the target. It uses Go's built-in net/http client with configurable timeouts and TLS settings. Each goroutine fires requests in a tight loop, recording latency in a lock-free histogram. At the end of the run, the main routine aggregates the histogram into percentile statistics and computes throughput.

Self-Hosting & Configuration

• Install via go install, Homebrew, or download static binaries from GitHub releases
• Set concurrency with -c and duration with -d (e.g., -c 100 -d 30s)
• Add custom headers with -H and set the HTTP method with -m (GET, POST, PUT, etc.)
• Supply a request body with -b for POST/PUT benchmarks
• Use --http2 to force HTTP/2 connections

Key Features

• Single static binary with no runtime dependencies
• Real-time throughput and latency display during benchmarks
• Detailed percentile latency distribution in the final report
• Cross-platform: runs on Linux, macOS, and Windows
• Low resource footprint on the client side even at high concurrency

Comparison with Similar Tools

• wrk — C-based benchmarker with Lua scripting; bombardier is simpler to install and cross-platform
• hey — similar Go-based tool; bombardier adds a real-time progress bar and HTTP/2 support
• ab (Apache Bench) — classic but single-threaded; bombardier uses goroutines for higher throughput
• vegeta — constant-rate load testing with rich reporting; bombardier focuses on max-throughput saturation
• k6 — full load-testing framework with scripting; bombardier is a lightweight single-command tool

FAQ

Q: What is the difference between -d and -n modes? A: -d runs for a fixed duration (e.g., 30s), while -n sends an exact number of requests regardless of time.

Q: Does bombardier support HTTPS? A: Yes. It handles TLS automatically. Use -k to skip certificate verification for self-signed certs.

Q: Can I send POST requests with a body? A: Yes. Use -m POST -b '{"key":"value"}' -H "Content-Type: application/json" to benchmark POST endpoints.

Q: How does it compare to wrk for raw throughput? A: wrk can achieve slightly higher RPS due to C and epoll, but bombardier is within the same order of magnitude and far easier to build and distribute.

Sources

• https://github.com/codesenberg/bombardier
• https://pkg.go.dev/github.com/codesenberg/bombardier