Locust
Load testing tools
- Features
- Ease of use
- Ease of management
- Quality of support
- Affordability
- Market presence
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$399 per month
Free Trial unavailable
Free version
Small
Medium
Large
- Information technology and software
- Banking and insurance
- Public sector and nonprofit organizations
What is Locust
Locust is an open-source load testing tool that lets teams define user behavior in Python and generate concurrent traffic against web applications and APIs. It is commonly used by developers, QA, and performance engineers to run load and stress tests locally or in distributed mode across multiple worker nodes. Locust emphasizes code-based test scenarios and real-time web UI reporting, making it suitable for CI-driven performance checks and custom protocol logic built in Python.
Python-based test scripting
Locust defines load test scenarios as Python code, which fits teams that already use Python for automation or backend services. This approach supports reuse of existing libraries and custom logic beyond simple recorded scripts. It also enables version control and code review workflows similar to other software artifacts.
Distributed load generation
Locust supports a master/worker architecture to scale load generation across multiple machines. This helps teams simulate higher concurrency without relying on a single load generator host. It is practical for running tests in containerized or cloud environments where workers can be added or removed as needed.
Open source and extensible
Locust is released as open source and can be extended through Python code and community plugins. Teams can integrate it with existing CI/CD pipelines and observability stacks using standard tooling and scripting. The open model can reduce licensing constraints compared with many commercial load testing platforms.
Requires coding to author tests
Locust is primarily code-driven and does not provide a full no-code workflow for building tests. Teams without Python skills may face a higher onboarding cost than with GUI-centric tools. Creating and maintaining complex scenarios can require software engineering practices rather than purely QA-oriented workflows.
Limited out-of-box enterprise features
Compared with many commercial platforms, Locust typically requires additional setup for centralized test management, role-based access control, and audit-ready governance. Features like integrated test data management, advanced reporting, and turnkey cloud execution often depend on third-party components or custom implementation. Organizations may need to build supporting infrastructure around it.
Protocol coverage depends on libraries
Locust is strongest for HTTP(S) workloads, while broader protocol support (for example, specialized enterprise protocols) may require custom clients or external libraries. This can increase implementation effort for non-HTTP systems. Some advanced browser-level performance scenarios may be better handled by tools designed specifically for real-browser execution.
Plan & Pricing
| Plan | Price | Key features & notes |
|---|---|---|
| Open-source (Self-managed) | $0 (MIT-licensed) | Install via pip; self-hosted; community support; run locally or distributed over your own infrastructure. |
| Free SaaS (Locust Cloud) | $0 / month | Up to 200 Monthly Virtual User Hours (VUh); up to 100 concurrent VUs per test; hosted load generation and persistent reporting (per pricing page). Note: Locust Cloud homepage currently indicates the cloud offering is shutting down (see notes). |
| Premium SaaS | $399 / month | 5,000 Monthly VUh; up to 1,000 concurrent VUs; hosted load generation; persistent reporting; professional support; team/access management up to 5 users; advanced AI-assisted scenario creation; OTel observability (per pricing page). |
| Enterprise SaaS | Custom pricing (contact sales) | Unlimited VUh; supports up to ~5,000,000 concurrent VUs; unlimited team/access management; SSO and enterprise features; professional support (contact sales). |
