An application needs to be tested for multiple dimensions. Usability testing, acceptance testing, and functional testing are mostly adopted in organizations. But, most organizations lack performance testing and load testing.
Load testing is non-functional testing but it can impact the usability and functionality. Load testing cannot be carried out with manual testing, there are specialized load testing tools, that help to test to the maximum load which your application can handle.
Table Of Contents
What are Load Testing Tools?
Load testing is a type of testing to examine the system behavior at normal and high loads. A load testing tool is a specialized software used to simulate the load on a system and it records the appropriate results and provides the output.
Load testing is done on a production-like system but not on production as it can impact the live users. Load testing helps in disaster recovery strategies and can help in keeping client impact to the minimum.
Types of Load-Testing Tools
Like functional test automation tools, there are many load-testing tools available in the market. Some are free and some are commercial. The load testing tools should be selected based on your needs. For example, if you are running a start-up, and your application is simple and small then if you choose an enterprise-class load testing tool, it may require a lot of unnecessary investment. The load testing tool can be classified into three different types.
Open-Source Load Testing Tools
These tools are open-source tools, managed by contributors. The open-source tools don’t offer much customization and you may need skilled experts. Similarly, the open-source tool usually doesn’t offer technical support, everything is community-driven. It is most suitable when you have a team of experts who can resolve the blockers with research.
Enterprise-class Load Testing Tools
The enterprise-class load testing tools offer more flexibility, customization, and technical support. Many tools even offer services. However, the tools are pricier. Based on the tool’s nature you may or may not have to spend on infrastructure. Mostly, when an organization has complex applications or fewer technical experts then they prefer to choose enterprise-class tools.
In-house Developed Load Testing Tools
Many organizations create their own load testing framework, which is maintained and developed in-house. The major advantage of this type is the tool is tuned as per organization standards, compliance, and requirements. These types of tools are highly customized to specific organizations. However, it also increases the burden of development and maintenance. In turn, it costs the organization.
Some organizations because of compliance or the nature of the application may not be able to use the open source or enterprise tools, then they prefer to choose such load testing framework.
Which factors should you consider while selecting a Load Testing Tool?
Let’s understand some of the basic factors to consider while choosing the load testing tools
- Evaluate the requirement against the load testing tool and choose the right one.
- Don’t be biased while choosing the load testing tool. Even if the skillset doesn’t match, if it fulfills all of your requirements it’s worth investing
- Decide on open-source tools vs enterprise tools
- Consider the learning effort involved, upskilling cost and time
- Consider the infrastructure setup and maintenance
- Perform POC on at least the top 3 most suitable tools before finalizing.
- Dashboard, reporting, scheduled triggers, and CI/CD integrations are some of the features that should not be ignored.
Top Load Testing Tools List
There are many load-testing tools available in the market. In this article, we have curated the best load-testing tools (Not ordered by ranks)
Apache JMeter
The JMeter is the most widely used performance and load-testing tool. It supports both API and UI load testing. It comes with bundles of features such as rich IDE, and drag-and-drop support. Interestingly it is open source. JMeter is easy to use, it is suitable for beginner to advanced users, and it also supports load testing via scripts.
Pros
- Open source
- Rich User Interface
- Easy to set up and learn
- Highly customizable
- A lot of community-driven plugins
- Supports multi-threading
- Multiple report types
- Customizable report data
Cons
- JMeter feels heavy as it consumes a lot of memory.
- The tool is not tuned for PC which has a lower configuration
- Because of architecture, the scripts become complex as they grow
Taurus
Taurus can be used with another load-testing tool. Taurus alone cannot produce the load testing results. The Taurus is used for hiding the complexity of the underlying tool. Turaus supports JMeter, Selenium and other tools.
Pros
- Makes the performance testing simpler with abstraction
- Open source; no need to spend on this tool
- The script can be written in simple JSON/YAML file
- The best way to incorporate load testing into the CI/CD pipeline
- Provides the abstraction on the underlying load testing tools
- It supports Mac, Windows, Docker, etc.
Cons
- The Taurus needs to rely on another load-testing tool. It can only provide an abstraction to other tools.
- Needs good technical skills to configure load testing tool with Tauraus.
Fiddler with BlackWidow and Watcher
The fiddler is used for network traffic monitoring, The BlackWidow is a web crawler that helps to drill down into domains. The Watcher is a security testing tool. Using the combination of these tools you can build a custom in-house load testing tool which serves as a performance testing, load testing, and security testing tool. However, we can’t deny the fact that architecture and usability become complicated. Furthermore, we should agree that it increases the complexity and demands for more skilled resources.
Some organizations may have such requirements and they can go for this tool.
Pros
- Helps to debug the traffic
- A lot of customization can be done as 3 major tools have come together
- Framework is custom-built, you can tune it as per your organization’s requirement
- Can serve as a security testing tool as well
- Helps to find the edge case scenarios in application performance
Cons
- The framework can become complex
- It might be difficult to enhance it beyond a certain level
- Load testing setup requires time
- Need to invest in infrastructure setup and maintenance
nGrinder
nGrinder is an open-source stress/load testing tool. As they claim on their GitHub page, it is an enterprise-level tool. It helps to create, manage, and execute the load tests and finally, it produces the result. It is maintained by Naver Corp.
Pros
- Testers can script using Jython or Groovy
- It uses the JVM to simulate the users
- Customizable by using libraries like .jar or .py
- Helps to monitor the bottlenecks in the application
- The reports are automatically combined and aggregated from multiple load-testing agents.
Cons
- The Github data shows that releases are not frequent.
- The community base is relatively low compared to other open-source tools
- The bugs are not fixed swiftly so the blockers can make a huge impact on your tests
The Grinder
Generally, the performance testing framework is combined with the load testing tool. The Grinder is specifically designed with load testing in mind. It uses the three-layered architecture Worker, Agent, and Console to simulate the desired load. It is a Java-based tool shipped with an open-source license
Note: A word of caution, though it works today, we have not observed any releases from May 2018 and we have not observed any activity from the last year as per GitHub data.
Pros
- Open source comes with zero cost
- Java-based tool and more developer-friendly
- Designed for high load testing and it serves the purpose
- Flexible scripting with Jython and Clojure
- Customizable with user plugins
- Comes with pre-defined charts, and stats that help in monitoring
- Automatically handles the client management and cookies
Cons
- Not actively developed
- The community is relatively small; difficult to resolve the issues
- Lacks documentation
Gatling
Gatling is a proprietary load-testing tool. It is an enterprise load-testing tool. However, Gatling is also available as an open-source tool with limited features. It includes a web recorder and rich reporting which helps to perform load testing without hassle
Pros
- Easy to install
- Simple tool easy to set up and start
- Easy to extend
- It has inbuilt-recording tool
- Helps to adapt shift left testing for load testing
Cons
- Using the free version it is difficult to generate high loads
- It lacks the granular level of information, during the execution
- No in-built monitoring integrations
K6
K6 is a modern load-testing tool, it allows load testing, performance testing, and back-end infrastructure testing. It also supports continuous performance testing. It is built with Go and Javascript integrates well into the modern development workflow.
Pros
- Easy to write the script
- Clean syntax
- Provides distributed and cloud execution
- You can also perform browser-level, front-end load testing using the xk6 extension
Cons
- Doesn’t generate a comprehensive HTML report
- Though it uses javascript scripting, because of k6 architecture it is difficult to start for beginners
- Distributed load generation is not available out of the box, one might have to rely on third-party plugins
Tsung
Tsung is a load testing tool that provides multi-protocol, distributed load testing capability. Any client-server application can be tested for higher load using Tsung. It supports HTTP, WebDAV, SOAP, PostgreSQL, MySQL, LDAP, MQTT, AMQP, and Jabber/XMPP protocols. Read here about Client Server Testing.
Pros
- You can monitor client’s CPU, memory, and network traffic
- It has an HTTP recorder
- The HTML reporter and graphs are a big plus
- It supports multiple protocols
Cons
- Limited support for Windows OS
- Not recommended for Windows-based applications
- The learning curve is relatively high, especially for beginners
- Correlation and parameterization are complicated
- Lacks documentation and less community support
Siege
Siege is an open-source, command-line load-testing tool for testing servers and web applications. Siege can target a URL and set of URLs. It provides many metrics such as response time, transactions per second, throughput, concurrency, etc. It can also simulate the user behavior using the cookies, headers, authentication, etc.
Pros
- Siege is a simple and easy tool
- It supports HTTP, HTTPS, and FTP protocol
- It supports basic authentication and SSL
- It can simulate up to 10K users and makes it suitable for large-scale testing
- It can be used for both client and server-side testing
- It can produce CSV and HTML reports
Cons
- It supports only a command line interface, no graphical interface
- Not many protocols are supported
- Siege may not behave in an expected way with dynamic contents
- Result accuracy is not that great
Fortio
Fortio is an open-source load testing library that provides a rich command line tool, serves most of the load testing requirement. Fortio allows users to specify a query-per-second load and record latency histograms and other useful stats.
Pros
- It is simple to install
- It is fast compared to other tools
- A tool with minimal dependencies and smaller in size
- Can be embedded into the Go library
- Can record latency histograms and other metrics
Cons
- Doesn’t scale well beyond 10K queries per second
- it is not optimized for high-load generation
- Adds sleep when responses don’t match
- Community support is limited
SoapUI
SoapUI is an API testing tool, that supports load testing based on existing tests. Based on existing functional tests you can validate web service behavior at high load. The ready API integration helps to simulate the load locally or on the cloud. It also helps to monitor server and database resources. Preconfigured templates are helpful to start quickly
Pros
- It can be used for both functional and non-functional tests
- Drag and drop support helps anyone to quickly create tests
- You can perform data-driven load testing with ease
- Templates are helpful to quickly start the tests
Cons
- The legacy UI is confusing for beginners
- Less stability compared to other load testing tools
- It requires WSDL for web service testing
Flood Element
Flood Element is a browser-based load-testing tool. It generates the load using browsers. It helps to create a realistic load just like users using the browser. It uses the Playwright tool behind the scenes to generate the load.
Pros
- Realistic load using browsers
- Data-driven load testing is a big plus
- Compatible with Selenium and Playwright
- Easy to simulate the users
- Rich HTML report
Cons
- Since it uses the browser-based load, may feel heavy
- Not much community support
- Documentation could have been better
Artillery.io
Artillery is a distributed load-testing tool. You can just install the npm package and start using it. The script can be created in .yml which increases the readability.
Pros
- It helps to test the maximum traffic with less hassle
- yaml scripting helps to understand the script for beginners
- It supports multiple protocols, including HTTP, Web Socket, Socket.IO, Kinesis, and HLS.
- You can create the custom logic, pre-test scenarios, and post-test scenarios using javascript
- The Playright automation tool can be easily extended for load testing with Artillery
- It Supports third-party plugins and is extendable
- It helps in continuous load testing
Cons
- Community support is limited
- Provides only CLI tool
- Lacks documentation
- Difficult to generate the report
How to Choose What’s Right for Your Load Testing Needs
We have listed top load testing tools, which can help you to shortlist the tools, however, you cannot directly jump to a conclusion. Choosing the right tool requires careful analysis below are the points you need to consider while analyzing the tool
- Open Source vs Enterprise tool: It is a well-known fact that open source tool reduces cost however it might be difficult to work with and requires more technical knowledge
- Consider skillsets: If your organization lacks the skills then you might need to adopt the low code performance testing tool.
- Budget: There is a cost involved in every step when you adopt the tool such as tool cost, upskilling cost, maintenance cost, infrastructure cost, etc.
- Ensure it fulfills requirements: Migrating to another tool in the future might incur heavy costs; analyze the tool considering future requirement
ConclusionThe non-functional testing such as load, performance, and stress testing is as critical as functional testing. The non-functional testing can have an impact on user experience and functionality. There are instances when the organization incurred loss because of heavy load and server crashes. However, unlike functional testing the NFT cannot be done manually you need to rely on load testing tools. Though there are many load testing tools available in the market you need to choose wisely based on requirements and budget.