cryload

Cross-platform HTTP load testing CLI: a modern ab/wrk alternative with machine-readable reports for CI/CD

cryload is a fast, single-binary HTTP load testing and benchmarking CLI: drive concurrent traffic against REST APIs, microservices, and static sites, measure requests per second, latency percentiles (p50–p999), status breakdowns, and transfer volume. Use it for stress tests, smoke tests before deploy, capacity checks, and GitHub Actions / pipeline automation via JSON or CSV output.

If you are looking for a hey-like or oha-like tool with extra reporting modes, or an ab / wrk alternative for HTTP scenarios without Lua scripting, cryload is built for that workflow. Implemented in Crystal for a small footprint and predictable performance.

Typical uses: bench Node, Go, Python, Rails, or .NET HTTP services; soak an API gateway or Kubernetes ingress; compare p99 latency after tuning; ship the same macOS, Linux, and Windows CLI to your team.

How cryload compares to ab, wrk, hey, and oha

Rough feature snapshot (tools evolve; check each project’s docs for the latest).

Choose wrk when you need Lua-driven scenarios and maximum tuning on Linux. Choose ab when the classic Apache Bench one-liner is enough—plain-text summaries, GET-heavy checks, and httpd-family packages already on the machine. Choose hey or oha when their defaults match your stack. Choose cryload when you want CSV / JSON reporting, rate limits, redirect handling, and histogram-style summaries in one cross-platform binary.

Why cryload?

• High-throughput HTTP load testing with a lightweight CLI experience
• Concurrent benchmarking with configurable connection count
• Request count mode (-n) and duration mode (-d) support
• Flexible request customization (method, headers, body, body-file, auth, user-agent, host header, timeout, TLS)
• JSON output mode for CI/CD and automation workflows
• Richer latency percentiles plus response/error breakdowns
• Optional global request rate limiting with --rate

Installation

Option 1: Install script (recommended)

Downloads the matching asset from Releases, verifies SHA256, and installs to ~/.local/bin (or %USERPROFILE%\.local\bin on Windows).

Linux / macOS (needs curl or wget, and sha256sum or shasum):

curl -sSfL https://raw.githubusercontent.com/sdogruyol/cryload/master/scripts/install.sh | sh -s

Install a specific version:

VERSION=v3.1.0 curl -sSfL https://raw.githubusercontent.com/sdogruyol/cryload/master/scripts/install.sh | sh -s

Windows (PowerShell):

iwr -useb https://raw.githubusercontent.com/sdogruyol/cryload/master/scripts/install.ps1 | iex

Option 2: Prebuilt binary

Download the matching asset from the Releases page (cryload-linux, cryload-macos, or cryload-windows.exe).

Linux:

chmod +x cryload-linux
./cryload-linux --help

macOS: Same as Linux, using the cryload-macos binary.

Windows (PowerShell or Command Prompt, from the directory containing the file):

.\cryload-windows.exe --help

Option 3: Build from source

Requires Crystal 1.19.0 or later.

git clone https://github.com/sdogruyol/cryload.git && cd cryload
shards build --release

The binary will be at bin/cryload.

Quick Start

Run your first benchmark in seconds:

bin/cryload http://localhost:3000 -n 10000 -c 100

Usage

cryload <url> [options]

Options:

Examples:

10,000 requests to localhost

cryload http://localhost:9292 -n 10000

10 seconds with 100 connections

cryload http://localhost:3000 -d 10 -c 100

Simple POST request

cryload http://localhost:3000/api/login -n 1000 -m POST

POST with plain text body

cryload http://localhost:3000/api/echo -n 500 -m POST -H "Content-Type: text/plain" -b "hello"

POST with JSON body

cryload http://localhost:3000/api -n 500 -m POST -H "Content-Type: application/json" -b '{"name":"cry"}' --timeout 5

POST JSON body from file

cryload http://localhost:3000/api -n 500 -m POST -H "Content-Type: application/json" --body-file payload.json

POST with multiple headers

cryload http://localhost:3000/api -n 300 -m POST -H "Authorization: Bearer token123" -H "X-Request-ID: benchmark-1" -b '{"ok":true}'

Basic auth request

cryload http://localhost:3000/private -n 300 --basic-auth username:password

Custom User-Agent and Host header

cryload http://127.0.0.1:3000 -n 300 --user-agent cryload-test/1.0 --host-header api.internal

Duration mode + timeout

cryload http://localhost:3000/api -d 15 -c 50 --timeout 3

Rate-limited run at 100 requests/sec total

cryload http://localhost:3000/api -n 1000 -c 50 --rate 100

Follow redirects

cryload http://localhost:3000/redirect -n 100 -L

Treat redirects as success without following them

cryload http://localhost:3000/redirect -n 100 --success-status 200-299,302

HTTPS with self-signed cert (skip TLS verification)

cryload https://localhost:8443 -n 1000 --insecure

JSON output for automation/CI

cryload http://localhost:3000/api -n 1000 --json

CSV output for scripts

cryload http://localhost:3000/api -n 1000 --output-format csv

Quiet mode for exit-code-only checks

cryload http://localhost:3000/health -n 10 --output-format quiet

Example output:

Preparing to make it CRY for 10 seconds with 100 connections!
Running load test @ http://localhost:3000/
Mode: duration (10s)
Connections: 100
Rate limit: unlimited
Success statuses: 200-299

Summary
  Total requests: 1696170
  Total time: 10.11s
  Requests/sec: 167803.62
  Responses: 1696170
  Transport errors: 0 (0.0%)
  Fastest: 0.19 ms
  Slowest: 35.39 ms

Status
  Successful: 1696170 (100.0%)
  Failed: 0 (0.0%)
  Success statuses: 200-299

Transfer
  Total data: 374.14 MiB
  Size/request: 231.0 B
  Transfer/sec: 37.01 MiB/s

Latency (ms)
  avg: 0.53   min: 0.19   stdev: 0.76   max: 35.39

Latency Percentiles (ms)
  p50: 0.41   p90: 0.81   p95: 0.96
  p99: 1.34   p999: 3.72

Latency Histogram (ms)
  3.390 ms [120] |■■
  6.590 ms [420] |■■■■■■■
  9.790 ms [1690630] |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■

Latency Distribution (ms)
  10.0% in 0.32
  25.0% in 0.38
  50.0% in 0.41
  75.0% in 0.55
  90.0% in 0.81
  95.0% in 0.96
  99.0% in 1.34
  99.9% in 3.72

Status Code Distribution
  [200] 1696170 responses (100.0%)

Built With Crystal

cryload is written in Crystal, combining Ruby-like developer ergonomics with compiled-language speed.

Automation and CI

Use --json or --output-format csv for scripts, dashboards, and GitHub Actions jobs: parse a single structured summary instead of scraping text. --output-format quiet is useful when you only care about exit status after a small health-check load. Combine with -n for fixed request counts so pipelines stay deterministic.

Contributing

1. Fork the repo
2. Create your feature branch (git checkout -b my-feature)
3. Commit your changes (git commit -am 'Add feature')
4. Push to the branch (git push origin my-feature)
5. Open a Pull Request

License

MIT