Tricentis Staff

Various contributors

Date: May. 11, 2022

What is a load testing tool?

Load testing is a way of ensuring that software works well under real-world scenarios.

A load testing tool is used to recreate the behavior of real users on a variety of software applications using virtual users (VUs). It can simulate anywhere between one and several million VUs, depending on the nature and requirements of the load test. This ability to reproduce so many users makes it an indispensable tool – as it is not possible for humans to conduct this kind of testing on such a large scale.

The tool can be used on-premise or in the Cloud. For extreme tests, where a large quantity of VUs is needed, many servers are required. In this case, testing in the Cloud is the better option as it is more easily scalable than an on-premise solution. A load testing tool is used to:

Create load testing scripts:

  • simulating the activity of each VU during testing

Configure test parameters:

  • What duration of testing is required, and for how many VUs?
  • How many different types of users will be included in the test?
  • How many desktop users versus mobile users?
  • Where will the load come from, on-premise or cloud infrastructure?

Perform the Test:

  • Execute test with the script and configured parameters in place
  • Define when it should be conducted
  • Consider running it from a Continuous Integration server (e.g., Jenkins)

Analyze the Results:

  • While the test is running and the application is on, the performance engineer must analyze software behavior
  • Such monitoring during operation can be done with the load testing tool or with other specific monitoring means (e.g., APM or Application Monitoring)

Here are considerations to take into account to understand how to choose the right load testing tool:

  • Why use a load testing tool?
  • Who uses load testing tools?
  • How to choose the perfect tool for your needs?
  • Are there different types of load testing tools?
  • What are the main tools for load testing?

Why use a load testing tool?

Using a load testing tool can identify and solve bottlenecks the system might experience in different scenarios. This helps prevent problems from occurring in a live production environment – which might negatively impact the business.

By conducting testing in realistic scenarios, the load testing tool helps protect against poor software performance – including unsavory response time. It can also be adapted to help manage and monitor performance levels in a live production environment.

Who uses load testing tools?

A load testing tool is used by a number of different professionals:

  • Performance engineers who work in performance test centers: These engineers need the most advanced tools to create the proper scripts and scenarios for effective testing.
  • Developers working in Agile/DevOps teams: Developers are becoming more involved in performance testing. When working within continuous monitoring processes, they start testing the first lines of code as soon as the firstAPIs are developed – even before a graphical user interface is available. These developers need a simple tool that doesn’t require a performance testing expert and one that can be used for API testing. As developers, they usually like to work in code – so the tool should ideally allow them to create tests using coding.

How to choose the perfect tool for your needs?

Settings organizations should consider when making your decision.

Test Script Design

Functional Description

  • Create realistic test scripts.
  • Design tests quickly, including complex ones.

Features and Benefits

  • For performance engineers: To create complex test scripts that simulate the diversity of real-world use cases.
  • For developers: To quickly generate API tests with code.

Technical Support

Functional Description

  • Support a variety of Web protocols – HTTP, Java, etc.; older protocols such as SAP GUI and Oracle Forms.

Features and Benefits

  • Provide extended protocol support so testers can test all their current applications.
  • Simulate complex protocol behaviours to create realistic tests.
  • Provide early support for emerging protocols.

Mobile Testing

Functional Description

  • Simulate mobile users.

Features and Benefits

  • Mobile behaviors are different from those of desktop. They must be isolated and simulated realistically – considering the specifics of mobile network conditions and different devices.

On-premise/Cloud Load Infrastructure

  • Functional Description
    Generate on-premise and cloud loads – or a combination.

Features and Benefits

  • An on-premise testing tool that is easy to install, but requires investing in your loading infrastructure
  • The cloud is more suitable for generating extreme load tests (those with thousands of VUs). It can create loads outside firewalls to simulate realistic conditions
  • Depending on the application being tested, it might be appropriate to adopt a combination of VUs using on-premise and cloud infrastructure.

Load Infrastructure Management

Functional Description

  • Manage/reserve load infrastructure.

Features and Benefits

  • In large organizations, it can be challenging to manage load infrastructure
  • Enable teams to collaborate and share test resources (such as load generators and VU licenses).

Tool Scalability

Functional Description

  • Scale to thousands or even millions of VUs.

Features and Benefits

  • Not all load testing tools can scale to accommodate significant tests with thousands or even millions of VUs.
  • Generate millions of VUs – either on-premise or in the Cloud
  • Synchronize tens or many hundreds of controllers to ensure that load generators are synchronized
  • Create test reports and analyses that aggregate this data for multiple controllers and load generators.

Load Testing Analysis

Functional Description

  • Analyze tested applications and identify bottlenecks

Features and Benefits

  • Must have its own monitoring capability or at least be capable of importing monitoring data for analysis
  • Must be able to provide actionable decision-making information to identify and help resolve bottlenecks

Integration with CI Pipeline

Functional Description

  • Integrate with Continuous Integration servers to automate performance testing

Features and Benefits

  • Does it provide standard integration with the most popular CI/CD servers?
  • Does it offer an API that enables integration with third parties?
  • Does it permit code-based testing for the integration of performance testing into a fully automated process?
  • Does it provide an automated success/failure SLA result, so that the test result can be fully automated?

Integration with Other Testing Tools

Functional Description

  • Integrate with other functional testing devices (e.g., Selenium)

Features and Benefits

  • Through integration with other tools the device lets you reuse existing, functional test scripts for load testing – speeding up the design phase.
  • Use “browser-based” performance indicators for the end-user experience


Functional Description

  • Enable different teams to collaborate on performance testing process and results analysis

Features and Benefits

  • Must let you share test resources (scripts, results, etc.) as well as the test infrastructure itself, including load generators and VU licenses.
  • Must support teams working together.


Functional Description

  • Ensure the security of the data being created (user logins and personal info, etc.).

Features and Benefits

  • Must encrypt the data it handles.
  • Must be completely secure, with absoutely no backdoors that could compromsie the safety of the data.

Technical Support

Functional Description

  • Support its customers in a variety of situations (different protocols and custom applications, etc.).

Features and Benefits

  • Testers must be able to customise protocols based on VUs to create realistic tests
  • Integrate performance testing into CI/CD pipelines to enable automation
  • Must provide testers with best practice guidance.

Are there different types of load testing tools?

There are several types of load testing tools, with varying yet complementary approaches:

  • Protocol-based tools: Generate protocol transactions at the application level. For example, requests on the HTTP protocol for web and mobile applications
  • Browser-based tools: Simulate the activity of real browsers, but for many different hundreds and even thousands of VUs

Load testing tools also come in different categories:

  • Tools-based on Open Source technology (JMeter): Simple use cases that do not require advanced testing capabilities
  • Advanced tools capable of providing a solution to suit even the most sophisticated needs: NeoLoad is one of the leaders and the main alternative to long-standing solutions like LoadRunner and Performance Center which have existed for decades

What are the main tools for load testing?



The leading load testing tool.

What need(s) are satisfied?
Suitable for all testing requirements – from API testing to individual application testing. Designed for the enterprise market and excellence test centers, as well as Agile/DevOps teams.

LoadRunner / Performance Center

Widely used in large organizations.

What need(s) are satisfied?
Meets the needs of large organizations. Supports complex use cases, but are dedicated for use by experts because they are just as complex to use.
Both are expensive to implement/maintain.


The Open Source load testing tool

What need(s) are satisfied?
Well suited to the basic requirements of load testing, but does not support legacy protocols such as SAP GUI. Requires third-party business tools for cloud and mobile testing.


Based on JMeter

What need(s) are satisfied?
Provides reporting and cloud computing capabilities in addition to the open source capabilities of JMeter.
Limited support for JMeter’s capabilities under complex testing conditions.


Tricentis Staff

Various contributors

Date: May. 11, 2022

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