Are you planning load testing for your website and looking for the best tools to do it? Or are you reading open-source load testing tools vs. commercial load testing tools blogs? This blog will break it down for you.

Load testing is a type of performance testing where you test your website performance under high traffic conditions. An expected load is generated using load testing tools, and various performance benchmarks are measured.  Load testing data and reports help identify bottlenecks and potential issues that downgrade the website performance and scope of optimization. Load testing and follow-up remediation help improve website speed, stability, and scalability.


Why Open-source Load Testing Tools?

When you decide to go for load testing, which you should, the first question that comes into your mind is what tools to use for load testing? This is one of the most important decisions you will need to make because choosing the right tool is the key to successful load testing and your website/application performance optimization. Every tool, whether the open-source or commercial variety, has its pros and cons, but you should always consider all the factors like accuracy, ease of use, ease of scripting, reliability, scalability, reporting, monitoring, and cost, etc. before choosing one.

Open-source load testing tools are often maintained by some of the great developers and are free to use with their source code available for customization as you require. You can use the open-source tool and extend its functionality for internal use. Some of the popular open-source tools are JMeter, Gatling, The Grinder, Locust, Tsung, and WebLOAD. The following are some of the pros and cons of using open-source tools that you should investigate carefully before selecting any tool:


Pros of using Open-source Load Testing Tools

  • No initial investment is needed as it is free to use.
  • Source code is available for extending the functionality based on internal use cases.
  • Managed by top developers and the open-source communities.


Cons of using Open-source Load Testing Tools

  • You need to invest in hardware to run open-source tools on your servers.
  • Building and maintaining the load testing infrastructure would require extra workforce and IT cost.
  • Virtual users (load) are generated on your internal servers, which leads to non-realistic conditions and misleading results as your end users would be coming from different devices and geo-locations.
  • The majority of open-source load testing tools support only protocol-based load testing and not browser-based load testing, which is not ideal as modern websites/applications rely heavily on browser-based JavaScript execution.
  • Open-source load testing tools have limited support, which means if you face any challenge in implementation or maintenance, you are pretty much on your own.
  • Security is a significant concern with open-source load testing tools.
  • Getting open-source load testing infrastructure up and running takes time.
  • Open-source load testing tools can affect your project timeline due to challenges and management required.
  • CPU and memory issues may arise when you run large load tests.
  • Scaling is hard as your application and users grow.


Popular Open-source Load Testing Tools



JMeter is by far the most widely used and popular open-source load testing tool that offers many features comparable to commercial load testing tools. You can record your test scripts and understand reports very easily. It is actively maintained and updated frequently to support new technologies.



Locust is also a popular open-source load testing tool based on Python. You can easily define user transactions and test them thoroughly. One of its significant advantages is it has a very friendly user interface so that you can understand the performance metrics fairly easily with charts, exceptions, failures, and other related information.



Gatling is a developer-friendly open-source load testing tool from websites and offers JavaScript APIs. You can write and execute complex test cases and integrate them into your CI/CD pipeline.


The Grinder

The Grinder is a Java-based open-source load testing tool based on Jython. It is useful for load testing your Java APIs. You can also use Closure language for writing test cases in Grinder.


When to Use Commercial Load Testing Tools

While we are talking about open-source load testing tools, let’s consider when to use commercial load testing solutions. Based on your business objectives, project timeline, and feature requirements, you can explore some of the best commercial load testing tools available in the market.  The following are some of the pros and cons of such tools:


Pros Of Commercial Load Testing Tools

  • Regular updates and extensive support
  • Relatively easy to set up and use.
  • Supports multiple protocols and browser-based load testing.
  • Real-time monitoring and advanced reports.
  • These can be easily integrated into the CI/CD pipeline.
  • Multiple geo-location supports for realistic conditions.
  • Easily scalable without any extra overhead.


Cons Of Commercial Load Testing Tools

  • These tools may be costly to use.
  • Load generation is usually limited to the plan/license you are subscribed to.
  • Extra features development decision is upon the vendor.


LoadView: The Practical Alternative to Open-source Tools

LoadView is a cloud-based load testing tool that gets you started with load testing your website/application quickly. It uses real browsers and devices to generate user load from multiple geo-locations, giving you the most realistic conditions for accuracy of results. Included is the EveryStep Web Recorder that lets you create test scripts with point-and-click features.

Even if you don’t have any programming experience, you can use it efficiently and get the most out of it. LoadView also allows you to adjust your loads in real-time for exploratory testing for capacity planning and scalability identifications. LoadView generates advanced reports that contain deep insights about the performance in a sorted manner so you can easily understand and identify bottlenecks to eliminate them quickly.


Summary:  Open-Source Load Testing Tools: Pros and Cons

Load testing is a must to perform for analyzing the speed, stability, and scalability of your websites, applications, and APIs.  There are both free and commercial load testing tools available in the market that you can choose based on your requirements. While open-source load testing tools require no initial investment, they come at the cost of building and managing your own infrastructure with limited features. Commercial load testing tools like LoadView offer rich functionality and features for accurate results and ease of use.  Read more about how LoadView compares to other load testing tools in the market.

Sign up for LoadView today and receive $20 in load testing credits.