Either you have a new website, or just developed some features that your users require, how do you make sure your website performs well when a high number of users start interacting with it? The answer is Load testing.  Load testing is a vital part of performance testing used to determine the behavior of a website, application, or software under normal and peak conditions. Load testing provides useful data that can improve your website performance and increase stability for expected load conditions.  Until recently, protocol-based load testing was the only method to test the website for the expected load conditions. As the technology and user experience are evolving, using real a Chrome browser allows testers to use a more realistic environment required for simulating real-users, and more accurate load test results.

In this article, we are going to talk about the following three widely used load testing approaches:

  1. Browser-based Load Testing (Using a regular Chrome Browser)
  2. Headless Browser Load Testing
  3. Protocol-based Load Testing


Chrome Browser-based Load Testing

Browser-based load testing simulates real-users by creating regular Chrome browser instances through load generators, and the website under test is navigated with the help of simple scripts. This creates an almost identical environment as real users in the real world. The virtual users in browser-based load testing are called Browser Level Users (BLU).  Browser-based load testing scripts have instructions related to actual navigation and interaction on the website. For example, which button to click, where to navigate, what information to feed in input boxes, how to interact with an element, when to interact with an element, and so on. This allows testers to simulate the most identical user journey as in the real world scenario.


Advantages of Real Browser-based Load Testing


User Perspective

Real-world end-users interact with the website using browsers, for example, in a real Chrome browser. Browser-based load testing allows you to load test your website with regular Chrome browser and understand the real-world user behavior.


Simple Scripts

For creating browser-based load testing scripts, you don’t need to have in-depth knowledge of underlying protocols. For example, if you want to create a login action, you just need the username and password to fill in, and which button to click to proceed, you don’t need to know the technicalities of authentication protocols and such.


Reduced Test Complexities

Unlike other traditional load testing methods where you need parameters and values to pass, browser-based load tests are easy to create and initiate with streamlined scripts.


Front-end Optimization

Browser-based load testing allows you to collect the most accurate real-world data, such as network and request delays, as your users also interact with your website using a regular browser. This helps in optimizing your front-end.


Low Maintenance

Simple scripts and less complicated tests means easier maintenance and more agility for load testing. For example, in our login example, if we change the authentication protocol, the login load test doesn’t need to be changed as it is not affected by that.


Disadvantages of Real Browser-based Load Testing


Higher CPU & Memory Usage

Browser-based load testing using a regular chrome browser, for example, require higher CPU and Memory to create instances for expected load. However, this should not be a problem if you use a cloud-based load test platform.


Occasionally Longer Runtime

Browser-based load testing involves rendering the complete website UI in a browser instance rather than simple API request-response recording. This can take longer than other load tests approached. However, it is often counter by the simplicity of running browser-based tests and an excellent cloud-based load testing tool.


Headless Browser Load Testing

Headless browser load testing involves running load tests in a browser environment without creating a ‘Head’ or user interface. This means load tests are run by creating invisible browser instances without any Graphical User Interface (GUI).  Headless browser load testing skips the rendering or drawing operations as nobody is watching the simulated browsers. It allows you to quickly run your load tests in a browser environment with fewer resources as compared to real browser-based load testing.  Examples of headless browser include the following:


Headless Chrome

Chrome Browser can be launched in headless mode with version 59 or later. It is lightweight and less resource-intensive, which can be used for navigation, collecting information on pages, generating PDFs, and taking screenshots.


Headless Firefox

Firefox also offers headless browser mode with version 56 or later. It can be used for basic tests with testing tools such as Selenium for Headless testing and automation.



PhantomJS is a flexible headless Webkit that has support for many standards for the web. JavaScript API is used for writing test scripts when using PhantomJS for testing. It is used mainly for navigation and assertion testing.


Advantages of Headless Browser Load Testing


Less Resource Intensive

As there is no GUI is rendered in the browser environment load testing, Headless Browser load testing allows you to generate more load with fewer resources.


Quicker Browser Environment Testing

With Headless Browser load testing, tests are quicker to execute and get results to fix potential problems quickly.


Disadvantages of Browser-based Load Testing

Limited Browser Environment Capabilities

While you can test many browser-based scenarios in the Headless browser testing, it is not enough to get a complete picture of real-world users who are using regular browsers like Chrome.


Lack of Browser Monitoring

Few test case scenarios require you to see your browser-based tests, such as animations, SPA transitions, and so on, to thoroughly analyze your load tests. Headless browser load tests do not have this capability.


Protocol-based Load Testing

Protocol-based load testing is the most traditional way of load testing by simulating the traffic at the HTTP/S level on load servers. It is primarily used for evaluating and assessing request-response exchange for the expected load on the server.  Protocol-based load testing is a minimal form of load testing, which alone is not suited to complex web applications that focused on user experience.


Advantages of Protocol-based Load Testing

Least Resource Intensive

Protocol-based load testing only involves generating HTTP/S request-response traffic that allows generating a very high load with minimum resources.


Faster Execution

Since only HTTP/S traffic is to be analyzed for protocol level metrics, protocol-based load testing offers faster test execution for higher expected load.


Disadvantages of Protocol-based Load Testing


Complex Tests

Protocol-based scripting requires an in-depth understanding of various protocols used on HTTP/S level, such as Oauth protocol for login. This makes scripting load tests complex and time-consuming process.


Least Realistic Environment

As opposed to real-world environments where users access your website using a regular browser like Chrome, Protocol-based load testing offers no such capabilities. It is not the right choice for websites that focus on the user’s perspective.


Lack of Capabilities for Modern Websites

Modern websites have more complex stacks now with heavy use of browser JavaScript and AJAX calls, for example, that makes protocol-based load testing limited in many test scenarios.


LoadView for Browser-based Load Testing

Based on what we have discussed so far, it is evident that browser-based load testing is the next evolution of load testing approaches. Today’s websites and technologies focus on rich user experiences and rely heavily on browser-side interpretation and rendering rather than server-side. Single-page Applications (SPAs) are now widely used with popular frameworks that use client-side JavaScript frameworks, and AJAX calls, for little to no page refresh for updating the UI.

LoadView offers cloud-based load testing using real browsers like Chrome to create the most realistic environment for your load test scenarios. With LoadView, you can easily create scripts for different user actions and behaviors and run your tests with few clicks.


What You Can Test with LoadView

  1. Websites
  2. Single Page Applications (SPAs)
  3. Third-party Service/APIs
  4. Media rich websites like streaming media services


Advantages and Benefits of LoadView for Real Browser-based Load Testing

  1. Easily create test scripts without writing a single line of code using EveryStep Web Recorder to load test all your pages.
  2. Over 40 real desktop/mobile browsers that enables you to test your web pages on virtually any device.
  3. Geo-distributed load testing allows you to test users from multiple locations for more accurate results in real-world scenarios.
  4. LoadView is DevOps friendly and offers multiple test curves to measure performance and optimize the web application.


Wrapping Up:  Benefits of Real Browser-based Load Testing

Browser-based load testing is a necessity for websites built on modern frameworks and media-rich content.  Load testing using real browsers like Chrome, which has more than 65% of the market share, provide you with plenty of performance results to quickly optimize your website. However, you should not limit yourself to just Chrome for load testing or a single device. Having the capability to test your website on virtually any browser or device from multiple geo-locations will give you comprehensive insights about your tests to analyze and optimize your website for the expected load.

Try LoadView today. Receive free load tests to get started with your Chrome browser-based load tests.