load testing

Published: 15 Dec 2022

Load Testing – An Overview, Types, Best Practices, and Tools

Last Updated: 10 Jun 2024

What is Load Testing?

Load testing is a part of performance testing (non-functional testing type), which includes an effective process of subjecting applications, websites, servers, networks, or systems to varying loads per their specification limits to check the stability of the app, server, network, or system. This testing method includes simulating a real-world load on any app or website to check how it responds to heavy user loads in real-time. Load testing checks whether the app or website meets the performance goals and objectives. Further, this testing method also determines the system behavior under normal conditions and anticipated or expected peak load conditions.

What is the Importance of Load Testing?

importance of Load Testing

The most critical part of web and mobile applications lies in their ability to deliver seamless performance to the end users. Undoubtedly, poor performance is bound to affect the customer experience as users prefer applications that provide great performance and are easy to use. Hence, to achieve seamless and high-performing apps, Load testing should be performed to evaluate the system’s response time and performance under varying loads. Businesses should adopt load testing as a part of their software development life cycle (SDLC) under both Agile and DevOps processes to get high-performing, scalable and robust apps.

Advantages and Disadvantages of Load Testing

Advantages and Disadvantages of Load Testing

Advantages of load testing

Helps to improve the scalability of apps and reduces downtime risk.

Helps to improve website traffic in case of holiday sales.

Helps to identify performance bottlenecks before deployment.

Discovers the performance of database components.

Verifies if the application meets the desired performance objectives.

Helps to uphold the reliability of the system.

Improves customer experience with scalable and robust systems in place.

Disadvantages of Load testing

Many of the load testing tools are licensed and needed to be paid to get the license

Some of the load-testing tools support only web applications

Some of these load-testing tools have limited compatibility

Some load tools might be challenging to test complex applications

Goals of Load testing

Goals of Load testing

To check how the website, app, or system performance under load conditions

Identify performance issues within the system for scalability, reliability, and stability under load conditions

Check the overall performance issues of critical business transactions, user flows, resource utilization, etc.

List types of load testing

types of load testing

Capacity testing:

This testing type, also called scalability testing, is used to identify the maximum number of users the system can support while not exceeding the page time as defined. The scalability testing method measures how far the system is scalable by adding resources. This testing method also measures the ability of the app to scale up or down when there is an increase in the number of users.

Stress testing:

This testing type helps to find out how a system behaves under extreme conditions such as breaking of the system, doubling the users, a database with less memory, etc.

Soak testing:

This testing type is used to know the trends and changes in the system behavior during a long duration of time.

Spike testing:

This testing method is used to check how the system can cope with sudden traffic spikes due to a sudden burst of traffic or heavy loads.

Best Practices of Load Testing

Best Practices of Load Testing

Identify business objectives for test preparation:

During the test preparation, the first important need is to identify the business objectives. This helps to recognize the type of tests to be performed, such as pre-production performance, stress, and capacity tests. Secondly, the requirement is to understand the use cases, such as considering the type of user requests, estimating the number of users to run the test, and identifying the behavior during load tests. The next phase is planning the test infrastructure, followed by deploying and tuning the test infrastructure.

Validate real-time performance with KPIs:

One of the best practices is to establish KPIs to measure the real-time performance of the application, such as the storage, response time, usage of the resources, etc.

Choose an effective Load testing tool:

Understanding the application technology stack plays an important role in choosing the right load testing tool. Several open-source and commercial load testing tools are available, but opting for the right tool can help achieve business goals.

Create load test cases based on user scenarios:

Effective load tests are the ones that simulate real-time traffic on the application instead of placing an unrealistic load on the system.

Build a replica of the production environment:

Concluding the load test results is difficult for businesses. If the test cases are run in a production-like environment (in terms of capacity and configuration), it can result in high business risk. Hence, businesses must replicate the production environment to avoid such scenarios.

Run Load tests to avoid bottlenecks:

It is a best practice to perform the load tests with a few users while preparing for the load test. Later, the number of users should be increased steadily. This way of running load tests will help to resolve the fluctuations once the user load increases.

How does Load Testing work?

How does Load Testing work

The QA teams need to follow the below steps to perform load testing:

Define key objectives and user scenarios

Identify the workload

Identify business SLAs

Choose the correct load test tool

Create test scripts

Create load test scenarios

Prepare the required test data

Run the load test

Record user transactions

How to do website load testing?

How to do website load testing

Understand the requirements

Determine which load test to perform

Identify the peak number of concurrent users expected to be handled by an app

Determine the usage model for the app and replicate the same while devising a load-test scenario

Develop automated scripts simulating user journeys for the identified business scenarios

Do not include third-party sites and CDN assets

Group different web pages into transactions

Execute the load tests

Monitor the web, applications, and database servers

Analyze the results and data

Share result analysis report along with actionable recommendations

Collaborate with developers and help them replicate the performance issues

Retest and assert the performance fixes once developers have implemented the tuning recommendations

Some Use Cases of Load testing

Some Use Cases of Load testing

eCommerce websites during Black Friday sales

Government websites during Income tax submissions

On-demand job portals accepting applications

Airline websites supporting some premium offers which attract huge traffic

All these use cases need end-to-end performance and load testing to ensure their websites and apps are scalable, stable, and robust enough to withstand heavy traffic.

Top Load Testing Tools for businesses

Common Open-Source Load Testing Tools

Apache JMeter




The Grinder


Commercial Load Testing Tools





IBM Rational Performance Tester





Today’s users prefer seamless and high-performing apps and systems to enjoy a great customer experience. Load testing is one form of performance testing that businesses should adopt during the SDLC to get stable, scalable, and robust systems, apps, and networks. Load testing is no longer a development need; businesses should adopt this testing method to ensure scalable apps even during peak loads. Hence, it is essential for companies to load-test applications using either paid or open-source load-testing tools to get scalable and stable apps.

How can TestingXperts Help businesses with Load testing?

TestingXperts (Tx) is Canada’s leading performance and load testing services provider for digital businesses across industries and domains. Leverage next-gen testing services provider for your solutions’ end-to-end digital and performance testing to deliver a seamless user experience.

Our performance testing services overview:

Predict application behavior and benchmark application performance.

Ensure your application is responsive, reliable, robust, and scalable.

Ensure your application meets all contractual obligations and SLAs for performance.

Comprehensive performance & load testing services across domains and technologies.

Detailed reporting with response times, breakpoints, peak load, memory leaks, resource utilization, uptime, etc.

Get in touch with our performance testing experts to learn more

Get in touch

During your visit on our website, we collect personal information including but not limited to name, email address, contact number, etc. TestingXperts will collect and use your personal information for marketing, discussing the service offerings and provisioning the services you request. By clicking on the check box you are providing your consent on the same. In the future, if you wish to unsubscribe to our emails, you may indicate your preference by clicking on the “Unsubscribe” link in the email.