Hey
A tiny HTTP load generator and ApacheBench replacement for sending load to web applications.
What is Hey?
hey is a command-line HTTP load generator designed to send load to web applications for performance testing. It replaces ApacheBench (ab) with more features like HTTP/2 support, rate limiting, and flexible request options. The tool helps developers and DevOps engineers assess how their applications handle concurrent traffic and identify performance bottlenecks.
Developers, DevOps engineers, and performance testers who need a simple yet powerful tool for load testing web applications and APIs.
hey offers a modern, feature-rich alternative to ApacheBench with better concurrency control, HTTP/2 support, and easy-to-use command-line options, all in a lightweight package.
Overview
HTTP load generator, ApacheBench (ab) replacement
Use Cases
Best For
- Load testing REST APIs and web services
- Benchmarking web application performance under concurrent traffic
- Simulating realistic user traffic with rate limiting
- Quick performance checks during development
- Comparing HTTP/1.1 vs HTTP/2 performance
- Automated load testing in CI/CD pipelines
Not Ideal For
- Teams needing graphical interfaces for real-time load test visualization
- Projects requiring complex, multi-step user journey simulations with conditional logic
- Organizations that prefer cloud-native load testing with integrated monitoring and analytics
- Testing scenarios demanding detailed, interactive reports beyond summary statistics or CSV
Pros & Cons
Pros
hey is a tiny binary with minimal dependencies, making installation and usage straightforward via clear command-line options, as shown in the quick start examples.
Supports various HTTP methods, custom headers, request bodies, and authentication, allowing detailed load test setups without complex scripting, evidenced by the -m, -H, and -d flags.
Includes HTTP/2 testing capability with the -h2 flag, enabling performance assessment for contemporary web applications that leverage this protocol.
Offers precise request rate limiting per worker (-q) and duration-based testing (-z), simulating realistic traffic patterns without manual intervention.
Cons
Only provides summary statistics or CSV export, lacking built-in graphical reports, advanced metrics, or integration with monitoring tools for deeper analysis.
Cannot define multi-step tests or conditional logic, restricting its use to simple, single-endpoint load testing without workflow simulation.
Relies solely on CLI, which may be less accessible for non-technical users or teams preferring web-based tools for collaboration and ease of use.
Open Source Alternative To
Hey is an open-source alternative to the following products:
Frequently Asked Questions
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