How to Load Test Web Applications

Getting Started with Load Testing Web Applications

Performance testing, more specifically load testing, is a type of non-functional testing that helps ensure that websites and web applications perform well under a variety of different loads, locations, and user scenarios.

Our increased reliance on technology makes it easier than ever for all of us to expect a certain level of performance from the websites and applications we use. In fact, 40% of people abandon a website that takes more than 3 seconds to load, and a 2 second delay during a sales transaction results in abandonment rates of up to 87%. Our demands and expectations fuel the need for performance testing, and it’s something that software teams recognize is important.

How to Load Test a Web Application

When you’re trying to understand how to get started with load testing for web applications it’s crucial to understand what the goals of your load tests are. Are you looking to test a specific user journey? Are you looking to test a specific piece of code? How many virtual users are you looking to generate? And so on. The first step to any successful load testing practice is understanding why you’re load testing in the first place, and what the big questions are that you’re looking to answer.

Next, understand what a realistic scenario for your web application is. Keep in mind, more often than not real-world data can be used to help guide your tests. For example, if you’re looking to test your web application to validate that a particular user journey or set of interactions with your application perform under load, but you aren’t sure what a typical load looks like, you can ask your Marketing or Operations teams to share data that they keep regarding the number of site visitors, device breakdowns, visitor locations, browser types, and other user data. This can help you map out a realistic, relevant scenario that can better reflect your application performance under load in production.

Once you’ve taken these two steps, getting started with creating load testing scenarios becomes a lot easier. This is when you should look to identify a performance or load testing tool that best aligns with your testing needs. Keep in mind that your approach to testing modern applications should involve validating the end to end performance.

Selecting a Load Testing Tool:

There are a variety of different tools on the market today to help you begin testing your web applications.  Each tool has its own highlights and drawbacks, so it’s essential to identify what works best for your teams’ needs.

LoadNinja Jmeter Blazemeter Neoload LoadRunner

Test Creation

Scriptless, point & click, no dynamic correlation required Requires scripting knowledge to playback and finalize tests. Cannot create test scripts, can only run scripts created in other tools (JMeter, Selenium etc). HTTPs transactions, users have to import NeoLoad’s certificate into system’s root. This opens up computer for serious security vulnerabilities. Playing back test scripts involves dynamic correlation– takes several hours or days.

Only works on PC. Playing back test scripts involves dynamic correlation– takes several hours or days.

Test Execution Runs in real browsers in the cloud (no additional cost or server maintenance required). Cannot execute test runs

Load generated from emulators and not real browsers.

Load generated from emulators and not real browsers.

Plus, required set up and maintenance of load generators in host machine.

Load generated from emulators and not real browsers.

Required to set up and maintain load generators in host machine

Set up cloud based load generators costs extra money.
Test Results Browser-based data – response times, navigation timings, and more. N/A - will vary depending on the tool you use to run the tests Performance results shown requests and responses – doesn’t show end user experience, Performance results shown requests and responses – doesn’t show end user experience Performance results shown requests and responses – doesn’t show end user experience
CI/CD Yes, LoadNinja REST API – Coming soon! Yes Yes Yes Yes
Pricing $$ Open-source $$ $$$$ $$$$

Understanding what you’re needs are from a tool is equally important. Some great questions to start with are:

  1. Do I want to test in real browsers?
  2. How many tests do I want to run?
  3. How many virtual users will I need for each test?
  4. How long will my tests be?
  5. Do I want to test apps in my private network?
  6. What’s my budget?

These can help you identify the tool that fits your bill & can help you start load testing your web apps.

Load Testing AngularJS, ReactJS, and/or AJAX applications

In the past, trying to load test AngularJS, ReactJS, and/or AJAX applications was fairly complex and required a lot of script rework to get the test to run properly. It could involve downloading new plugins, trying to work with Selenium WebDriver to simulate certain browser behaviors, etc.

Nowadays though, with LoadNinja, you can simply record the test (interacting how a user would with the web application) and immediately replay the test in a browser without scripting a single line of code. This is due to a few things but the main two drivers are:

  1. Recording, replaying and testing in real browsers
  2. Object-level recognition to identify recorded objects for faster and more accurate detection during playback

To learn see how to record tests and get started with load testing in LoadNinja check out this introductory session.


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Ensure your web applications reliably perform under any condition

  • Record and playback test scripts in minutes with no dynamic correlation or coding
  • Generate accurate load with real browsers at scale for realistic performance data
  • Analyze browser-based performance data that developers and testers can understand out of the box
  • Visualize, isolate and debug any performance issue Virtual Users encounter