TOOL SIGNAL / ACTIVE

Locust

Locust authors

Load Testing Open Source Self-hosted ✓ pick

MAINTAINED BY · Locust is maintained by a community of contributors, with top contributors including cyberw, heyman, andrewbaldwin44, and others.

Official site ↗ Source repo ↗
Pricing model
Free; MIT License.
First released
2011
Latest release
2.46.2
Last verified
Answer

Locust is an open-source, modern load testing framework that allows users to write scalable load tests in plain Python, avoiding the need for clunky UIs or XML.

About

Locust is an open-source, modern load testing framework that allows users to write scalable load tests in plain Python, avoiding the need for clunky UIs or XML.

Best for

  • Load Testing scenarios across typical web and service stacks
  • Teams that prefer open-source licensing and self-hosting options
  • Groups comfortable scripting in Python

Not the best fit when

  • Teams unwilling to operate generators, results storage, and scaling

Architecture and concurrency

Locust is commonly operated as self-hosted software with scenario authoring in Python. Concurrency and distribution depend on how you size workers or injectors.

Compare and alternatives

Locust vs k6 Open Source · Self-hosted Apache JMeter vs Locust Open Source · Self-hosted Locust vs LoadRunner Professional Commercial · Self-hosted Locust vs NeoLoad Commercial · Hybrid Locust vs BlazeMeter Commercial · Cloud Locust vs Tsung Open Source · Self-hosted Locust vs The Grinder Open Source · Self-hosted Locust vs Azure Load Testing Commercial · Cloud Locust vs AWS Distributed Load Testing Open Source · Cloud Locust alternatives 12 alternatives compared

Features

  • Plain Python test scripting
  • Distributed testing capability
  • Real-time statistics monitoring
  • Scalable to simulate millions of users
  • MIT open-source license

Latest release

2.46.2 · 2026-07-24

Version 2.46.2 includes fixes for response time percentile calculations, updates to StatsEntry typing, and various dependency bumps in the web UI.

Pricing

The open-source core of Locust is free. Separately, Locust Cloud offers paid, usage-based SaaS plans for hosted infrastructure and reporting.

Specs

Scripting
Python
Protocols
HTTPHTTPSWebSocket
Operating systems
WindowsmacOSLinux
Tags
pythondistributedweb-ui
Repo health
★ 28116 · last push 2026-08-26

Sources

SHOW SOURCES

LAST VERIFIED · 2026-08-11 · GROUNDED VIA EXA · CURATED BY NAVEENKUMAR NAMACHIVAYAM

Frequently asked

ANSWER-SHAPED
Who is Locust for?

Locust is best for engineers designing load, stress, and performance tests for web and service systems. It is open source, so teams can self-host and extend it. Vendor: Locust authors. Deployment model: self-hosted. Free; MIT License. Confirm details against the official site and a short proof-of-concept in your environment.

How does Locust differ from Apache JMeter?

Compared with Apache JMeter, scripting centers on Python rather than Java, Groovy. Locust lists protocols HTTP, HTTPS, WebSocket; Apache JMeter lists HTTP, HTTPS, JDBC, JMS, FTP, TCP. Status is active versus active. Use the Test Rig to compare full specs side by side before a proof-of-concept.

What scripting language and concurrency model does Locust use?

Locust uses Python for scripting or scenario definition. Runtime model: code-first scenarios where virtual users execute scripted behavior under load. OS support: Windows, macOS, Linux. Protocols: HTTP, HTTPS, WebSocket. Match these to how your team already authors tests and which systems you must drive under load.

What is the cloud or enterprise path for Locust?

Locust is primarily self-hosted; teams typically run generators on their own machines, CI runners, or private cloud. Plan for generator capacity, network access to targets, and result storage yourself. As open source, commercial support or hosted siblings may exist separately. Check the official site. Pricing note: Free; MIT License.

What are known limitations of Locust?

Locust limitations to weigh: self-hosted tools require you to provision, scale, and observe load generators yourself. Status: active. Always validate against your target protocols and scale with a proof-of-concept. Confirm details against the official site and a short proof-of-concept in your environment.