JMeter vs Locust

JMeter and Locust both are used as performance testing tools.JMeter is released 25 years ago, it is written in pure Java and is more established while Locust is written in Python and is an emerging tool

Let’s compare JMeter and Locust in various aspects:

Scripting and Test Creation:

In JMeter, primarily GUI mode is used for test creation, which makes it easy to use by non-coders or without extensive programming experience.

Locust is code-centric, it requires Python coding skills for test creation.

Having all test scripts in code is advantageous in case of test case modifications, and can be easily managed and verified using VCS(Git).

Simple Test case creation is fast in JMeter as it is GUI-based but maintaining, modification and verification is better in Locust.

Protocol Support:

JMeter supports multiple protocols including HTTP, HTTPS, FTP, JDBC, SOAP, REST, and more. It is written in Java.

Locust is primarily designed for HTTP-based applications and APIs. It is written in Python and supports custom protocols through the use of Python libraries.

Scalability:

JMeter follows a thread-based model where each user is allocated a separate thread, this allocation of threads requires a large amount of resources. It limits the number of concurrent users that can be simulated on a single machine. Running JMeter in GUI mode also consumes significant memory resources.

Locust adopts an event-driven and async approach, using the gevent coroutine library. This allows Locust to easily simulate thousands of concurrent users on a single machine, even on regular hardware, while running complex tests with multiple steps.

Locust’s lightweight execution makes it advantageous when dealing with a large number of concurrent users.

Ramp-Up Flexibility:

In Jmeter flexible load can be configured easily and it also supports third-party plugins to further configure flexible load.

In Locust, the custom flexible load can be generated using LoadTestShape Class. It provides you full control over user count and spawn rate.

Load Test Monitoring:

JMeter offers built-in monitoring elements which provide various metrics and visual representations of the load test results.

Locust provides basic built-in monitoring, such as a web interface that shows reals time statistics such as no. of requests, response times, failure rate, etc.

Both tools can be integrated with External monitoring tools.

JMeter vs Locust Comparison Table

Summary:
Locust is more developer friendly, an easy-to-use, scriptable, and scalable performance testing tool. You define the behavior of your users in regular Python code, instead of being stuck in a UI.
JMeter is GUI-based and can be easily used by non-programming background users and supports more protocols and third-party plugins.