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.
Rough feature snapshot (tools evolve; check each project’s docs for the latest).
| cryload | ab | hey | oha | wrk | |
|---|---|---|---|---|---|
| Language | Crystal | C | Go | Rust | C |
Concurrent connections (-c) |
✓ | ✓ | ✓ | ✓ | ✓ |
Duration / request count (-n) |
✓ | ✓ (-t / -n) |
✓ | ✓ | ✓ |
| JSON / CSV / quiet output for CI/CD | ✓ | — (text) | JSON | JSON | — (text / Lua) |
| Text latency histogram + distribution | ✓ | basic | limited | TUI-focused | basic |
Global RPS cap (--rate) |
✓ | — | — | ✓ | different model |
| Follow redirects, custom success HTTP codes | ✓ | — | partial | partial | — |
| Scriptable load (Lua, etc.) | — | — | — | — | ✓ |
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.
- 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
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 -sInstall a specific version:
VERSION=v3.1.0 curl -sSfL https://raw.githubusercontent.com/sdogruyol/cryload/master/scripts/install.sh | sh -sWindows (PowerShell):
iwr -useb https://raw.githubusercontent.com/sdogruyol/cryload/master/scripts/install.ps1 | iexDownload the latest prebuilt binary from the Releases page, then make it executable:
chmod +x cryload
./cryload --helpRequires Crystal 1.19.0 or later.
git clone https://github.com/sdogruyol/cryload.git && cd cryload
shards build --releaseThe binary will be at bin/cryload.
Run your first benchmark in seconds:
bin/cryload http://localhost:3000 -n 10000 -c 100cryload <url> [options]Options:
| Option | Description |
|---|---|
-n, --numbers |
Number of requests to make |
-d, --duration |
Duration of test in seconds |
-c, --connections |
Concurrent connections (default: 10) |
-m, --method |
HTTP method (default: GET) |
-b, --body |
HTTP request body |
--body-file |
Read HTTP request body from file |
-H, --header |
HTTP header, repeatable (-H "Key: Value") |
--user-agent |
Set the User-Agent header |
--host-header |
Override the Host header |
-a, --basic-auth |
HTTP Basic auth in the form user:password |
--timeout |
Client connect/read timeout in seconds |
-q, --rate |
Total request rate limit in requests/sec |
-L, --follow-redirects |
Follow HTTP redirects up to 5 hops |
--output-format |
Output format: text, json, csv, quiet |
--success-status |
Treat specific status codes/ranges as successful |
--insecure |
Accept invalid TLS certificates for HTTPS |
--json |
Print final result as JSON |
-h, --help |
Show help |
Examples:
10,000 requests to localhost
cryload http://localhost:9292 -n 1000010 seconds with 100 connections
cryload http://localhost:3000 -d 10 -c 100Simple POST request
cryload http://localhost:3000/api/login -n 1000 -m POSTPOST 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 5POST JSON body from file
cryload http://localhost:3000/api -n 500 -m POST -H "Content-Type: application/json" --body-file payload.jsonPOST 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:passwordCustom User-Agent and Host header
cryload http://127.0.0.1:3000 -n 300 --user-agent cryload-test/1.0 --host-header api.internalDuration mode + timeout
cryload http://localhost:3000/api -d 15 -c 50 --timeout 3Rate-limited run at 100 requests/sec total
cryload http://localhost:3000/api -n 1000 -c 50 --rate 100Follow redirects
cryload http://localhost:3000/redirect -n 100 -LTreat redirects as success without following them
cryload http://localhost:3000/redirect -n 100 --success-status 200-299,302HTTPS with self-signed cert (skip TLS verification)
cryload https://localhost:8443 -n 1000 --insecureJSON output for automation/CI
cryload http://localhost:3000/api -n 1000 --jsonCSV output for scripts
cryload http://localhost:3000/api -n 1000 --output-format csvQuiet mode for exit-code-only checks
cryload http://localhost:3000/health -n 10 --output-format quietExample 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%)
cryload is written in Crystal, combining Ruby-like developer ergonomics with compiled-language speed.
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.
- Fork the repo
- Create your feature branch (
git checkout -b my-feature) - Commit your changes (
git commit -am 'Add feature') - Push to the branch (
git push origin my-feature) - Open a Pull Request
MIT