Write Performance Tests
in JavaScript online

A powerful test site for software developers, easy to use, Loadsy’s engineering the future of load testing tools.

Run up to 512 threads for up to 30 seconds for free.


Performance testing straight from your terminal.

We blend the most powerful features from conventional performance testing tools and improved the way scripts are created.

Designing a performance test with Loadsy is easy. Our intuitive load testing tool helps you to steep the learning curve. From beginners to experts, allowing your team to create tests with JavaScript code without any additional integrations.

Loadsy, the performance testing tool that is

Intuitive, modern and complete

Simplify stress testing and apps perform


Write and run any kind of performance test with just one tool : load, stress, spike, and scale.

Enterprise Ready

Enterprise ready solution for your engineering team

Simplified Script Creation

Write scripts and test complex scenarios using a stack your developers are already familiar with.

Automated Tests

Integrate Loadsy into your CI/CD pipeline to safeguard against any release that adversely impacts your scalability and performance.


Get real-time and aggregated performance metrics for each endpoint in your tests.

Data Reports

Export pdf's and share performance test results with your executive team.

Simulate Complex Scenarios

Run them at scale as part of your continuous testing strategy. Test and generate detailed reporting and see historic trends.

Easy testing for everyone

Loadsy is here to make your life simpler, allowing your personalized, automized and complex tests.

Worried about your dev team’s bandwidth?

What a brand new resource, You can try our resource and explore how it works