Alternatives to Loader.io

Cloud load testing service that simulates many concurrent connections against web apps and APIs. The listings below can replace it for an important use case. Each note says what changes if you switch.

  • Loader.io

    Cloud load testing service that simulates many concurrent connections against web apps and APIs.

    FreemiumProprietaryWeb

Replacements

Listings that take over the same core job as Loader.io.

  • Grafana k6

    An open-source command-line load testing tool that runs test scripts written in JavaScript.

    FreeOpen sourceCommand line

    Grafana k6 is a free open-source CLI with JavaScript test scripts, so load is generated from your own machines rather than a hosted service.

  • Artillery

    Load testing and Playwright end-to-end testing toolkit with an open-source CLI and an optional cloud dashboard.

    FreemiumOpen sourceWebCommand line

    Artillery is an MPL-2.0 CLI that can run on your own AWS or Azure infrastructure, with an optional cloud dashboard and Playwright testing.

  • Apache JMeter

    An open-source Java application for load testing and measuring the performance of web applications and servers.

    FreeOpen sourceWindowsmacOSLinuxCommand line

    Apache JMeter is a free Apache-2.0 Java application you run yourself, covering many protocols with distributed testing across machines.

  • Gatling

    A load testing tool for web applications and APIs, with an open-source edition and hosted enterprise platform.

    FreemiumOpen sourceWebCommand line

    Gatling has an open-source Community Edition with tests written as code, and a paid Enterprise Edition with CI automation.

  • Locust

    An open-source load testing tool where user behaviour is defined in plain Python code.

    FreeOpen sourceWindowsmacOSLinuxCommand line

    Locust is open source and scripts user behaviour in Python, running on your own machines with distributed support.

  • Vegeta

    Command-line HTTP load testing tool that sends requests at a constant rate.

    FreeOpen sourceWindowsmacOSLinuxCommand line

    Vegeta is an MIT-licensed CLI that sends HTTP requests at a constant rate from your own machine, without complex flow scripting.

  • Siege

    Command-line HTTP load tester that stress-tests web servers with simulated concurrent users.

    FreeOpen sourcemacOSLinuxCommand line

    Siege is a GPL-3.0 command-line HTTP stress tester for macOS and Linux, simulating concurrent users from a terminal.

Similar software

Related functionality, not a direct replacement.