Siege
Siege: Open Source Load Testing and Benchmarking Utility
Test web applications stability and performance under heavy load with Siege, an open source tool for load testing and benchmarking.
What is Siege?
Siege is an open source load testing and benchmarking utility designed specifically to test web applications. It allows developers to simulate a large number of concurrent users accessing a web application to test its performance and stability under heavy load.
Some key features of Siege include:
- Ability to simulate hundreds or thousands of concurrent users from a single machine
- Flexible configuration of user scenarios and access patterns
- Text-based output for statistics like response times, transaction rates, concurrence levels, and response status
- Authentication support with GET, POST, Basic Auth, Cookies, etc.
- SSL/TLS support
- Customizable HTTP header values
- Docker support for easier cloud deployments
- Scriptable using command files for automated tests
Siege is often used for capacity planning, benchmarking against alternative solutions, analyzing application bottlenecks, and monitoring web application performance over time. It is free and open source, available for Linux, Solaris, and macOS platforms.
Siege Features
Features
- Load testing
- Stress testing
- Benchmarking
- HTTP/HTTPS protocol support
- Authentication support
- Concurrent virtual users
- Customizable test scenarios
- Command line interface
- Detailed performance metrics
Pricing
- Open Source
Pros
Cons
Official Links
Reviews & Ratings
Login to Review7 reviews
Rating Breakdown
Recent Reviews
Finley Hill
May 10, 2026A Developer's Trusty Tool for Simple, Effective Load Tests
As a backend developer, Siege has been my go-to for quick and reliable load testing. The command-line interface is straightforward, letting me simulate hundreds of users hitting my API endpoints in seconds. It's perfect for catching performance regressions before they …
River Taylor
May 09, 2026A Developer's Go-To for Simple, Effective Load Testing
Siege has been incredibly reliable for quickly stress-testing our API endpoints before deployment. The command-line interface is straightforward, and the ability to simulate concurrent users with just a few flags makes my workflow much smoother. While it lacks the fancy …
Avery Smith
May 07, 2026Clunky and Unreliable for Modern Load Testing
While Siege is free, it feels incredibly dated and frustrating to use. The command-line syntax is arcane and poorly documented, making it hard to set up even basic test scenarios. When I finally got it running, the results were inconsistent …
Lisa Miller
May 02, 2026Indispensable for basic web app load testing
Siege has been a staple in my toolkit for quickly checking how my web apps handle concurrency. The command-line interface is straightforward, and setting up a simple test with a URL list and user count takes seconds. While it doesn't …
Dakota White
Apr 30, 2026A Developer's Go-To for Simple, Effective Load Testing
Siege has been a fantastic tool for quickly stress-testing our web APIs during development. The command-line interface is straightforward, and being able to simulate hundreds of concurrent users with a single command has helped us catch performance bottlenecks early. The …
Rating Distribution
The Best Siege Alternatives
View all Siege alternatives with detailed comparison →
Top Development and Testing and other similar apps like Siege
Here are some alternatives to Siege:
Suggest an alternative ❐
Locust
Apache JMeter
Apache Benchmark
Wrk
