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locust vs Siege

Locust for complex, scriptable load tests with a web UI and distributed mode. Siege for quick, simple HTTP benchmarks from the command line. Locust is a testing framework; Siege is a benchmarking tool.

locust icon
locust
Siege icon
Siege

locust vs Siege: The Verdict

⚡ Quick Verdict:

Locust for complex, scriptable load tests with a web UI and distributed mode. Siege for quick, simple HTTP benchmarks from the command line. Locust is a testing framework; Siege is a benchmarking tool.

Locust and Siege both generate HTTP load, but at very different levels of sophistication. Locust is a full load testing framework — you write Python code defining user behavior, run distributed tests across machines, and monitor results in a real-time web UI.

Siege is a command-line HTTP benchmarking tool. Point it at a URL (or a file of URLs), set concurrency and duration, and get throughput numbers. No scripting, no web UI, no distributed mode. It's the `ab` (Apache Bench) replacement that handles more realistic scenarios.

For answering 'can my server handle 1000 concurrent users doing complex workflows,' Locust is the right tool. For answering 'what's my homepage's throughput under load,' Siege gives you the answer in one command.

Siege's simplicity is its strength for quick checks. No Python files to write, no framework to learn. But that simplicity caps out quickly — the moment you need login flows, session handling, or conditional logic, you need Locust.

Who Should Use What?

🎯
Quick throughput benchmark of a URL: Siege
One command, instant results — no scripting or setup required.
🎯
Complex user journey simulation: locust
Python code models any user behavior including login, cart operations, and API sequences.
🎯
Distributed load testing across machines: locust
Built-in master/worker architecture scales to millions of virtual users.
🎯
CI/CD smoke test for performance regression: Siege
Simple command-line tool integrates easily into CI pipelines for basic performance checks.
🎯
Real-time monitoring of test progress: locust
Web UI shows live request rates, response times, and error rates during the test.

Last updated: May 2026 · Comparison by Sugggest Editorial Team

Feature locust Siege
Sugggest Score 31 31
User Rating ⭐ 4.1/5 (19) ⭐ 4.2/5 (3)
Category Development Development
Pricing Open Source Open Source
Ease of Use 3.2/5 4.0/5
Features Rating 4.5/5 4.0/5
Value for Money 4.8/5 5.0/5
Customer Support 3.2/5 3.0/5

Product Overview

locust
locust

Description: Locust is an open source load and performance testing tool written in Python. It allows developers to test the performance of their web applications by simulating large numbers of concurrent users making requests.

Type: software

Pricing: Open Source

Siege
Siege

Description: Siege is an open source load testing and benchmarking utility for web applications. It allows developers to put load on a web server to test application stability and performance under heavy load.

Type: software

Pricing: Open Source

Key Features Comparison

locust
locust Features
  • Distributed load testing
  • Scripting using Python
  • Simulate thousands of concurrent users
  • Web-based UI
  • CSV results output
  • Can test any system that has a HTTP interface
Siege
Siege Features
  • Load testing
  • Stress testing
  • Benchmarking
  • HTTP/HTTPS protocol support
  • Authentication support
  • Concurrent virtual users
  • Customizable test scenarios
  • Command line interface
  • Detailed performance metrics

Pros & Cons Analysis

locust
locust
Pros
  • Open source
  • Easy to use
  • Scalable
  • Good documentation
  • Active community support
Cons
  • Only supports HTTP protocol
  • Limited reporting capabilities
  • Steep learning curve for advanced usage
Siege
Siege
Pros
  • Open source
  • Lightweight and easy to use
  • Cross-platform
  • Highly customizable
  • Can simulate thousands of concurrent users
  • Good for testing app scalability
Cons
  • Limited reporting compared to commercial tools
  • Steep learning curve
  • Only supports web apps, not other services
  • No GUI
  • Can underestimate large-scale production loads

Pricing Comparison

locust
locust
  • Open Source
Siege
Siege
  • Open Source

Frequently Asked Questions

Is Locust overkill for simple benchmarks?

Yes — if you just need throughput numbers for a URL, Siege (or wrk, or hey) gives you results in seconds without writing any code.

Can Siege simulate user sessions?

Siege can send cookies and use URL lists, but it can't model complex user flows with conditional logic. For that, you need Locust or similar frameworks.

Which is easier to learn?

Siege — it's a single command with a few flags. Locust requires writing Python code, though the API is simple for Python developers.

Are both free?

Yes — both are open-source. Siege is GPL licensed, Locust is MIT licensed.

What about wrk or hey as alternatives?

wrk and hey are even simpler than Siege for raw HTTP benchmarking. Use them for pure throughput testing. Use Siege for URL-list testing. Use Locust for behavioral testing.

⭐ User Ratings

locust
4.1/5

19 reviews

Siege
4.2/5

3 reviews

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Learn More About Each Product

locust
locust
Reviews, pricing & alternatives →
Siege
Siege
Reviews, pricing & alternatives →

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