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Guide to UI Performance Testing

By Shormistha Chatterjee, Community Contributor -

As of Jan 2023, there were around 5.16 billion internet users globally, which is 64.4% of the entire global population. Of this total, 59.4 percent, or 4.76 billion of the world’s population, were social media users. 

No. of Internet and Social media users till Jan2023Source

It means your website or mobile app must have a great UI design to engage and attract users. A clean design, visual aesthetics, ease of use, and great functionality are all hallmarks of a perfectly designed UI. A messy UI that isn’t intuitive to use or aesthetically pleasing will quickly turn away customers and cause a massive loss of revenue.  

What is UI Performance Testing?

User Interface (UI) testing, or GUI testing, tests the app’s visual components to validate appropriate functionality and expected performance. 

  • UI performance testing certifies that UI functions and application elements have zero defects, such as radio buttons, icons, text boxes, color, toolbars, fonts, menus, checkboxes, and windows. 
  • The prime aspects of UI testing are performance, functionality, compliance, usability, and visual design of the software app to ensure the application works satisfactorily and successfully.

Understanding the Importance of UI 

As per Localytics, 71% of all mobile app users churn within ninety days. Overall, UI designers should bring a leading edge to the project, making your application or website stand out among the millions of other options.

Whether it is a site, a mobile app, or a web app, user interface testing is necessary for companies to build a lasting impression on the niche audience. UI performance test enhances the software quality, and guarantees end-users are comfortable using the application.

UI/UX is vital in the following ways:

Boosts User Satisfaction & Enhances ROI

A better website design gives your visitors easy-to-use navigation and appealing content. This makes the users satisfied with the services of your app/ website. Besides, the satisfied clientele will be a source of higher conversions as they will also endorse your business to others.

Apart from this, they could be turned out as a loyal customer to your business and will come back again. Upon this, your ROI would easily increase.

Raises your Brand and Reputation

When you invest in a better UI/UX design, it assists in consumer satisfaction, directly leading to customer satisfaction. Even people love visiting the brands that make them happy. It enhances trustworthiness and credibility and your niche client develops better relationships with your company and brand. All this results in the growth of your entire business. 

Saves your Precious Time and Money

When you invest in a better UI/UX design, it assists in consumer satisfaction, directly leading to customer satisfaction. Even people love visiting the brands that make them happy. It enhances trustworthiness and credibility and your niche client develops better relationships with your company and brand. All this results in the growth of your entire business. 

Saves your Precious Time and Money

When you will invest in UI/UX design, then there is a lesser chance that the clients will find any errors in your website. Besides, a complete and faultless product will not require time-to-time upgrades, saving money and time. 

Quick Tip: You can also execute website speed tests on SpeedLab for free. Simply enter the website URL, and get a descriptive report on your site speed as it runs on real devices, browsers, and operating systems.


Also, conduct Geolocation testing to ensure your website delivers content localized to a user’s location.

Try Geolocation Testing

Types of UI Performance Testing

This is a complex and multifaceted activity that cannot be approached similarly for all applications. With knowledge of the different types of performance testing, it is possible to create a successful performance test plan.

  • Stress testing –  involves testing an app under extreme conditions to understand how it handles data processing/ heavy traffic. The core objective is to detect the breaking point of an app. 
  • Load testing – UI load testing checks the app’s capacity to execute under projected user loads. The objective is to detect performance bottlenecks before the software app goes live.
  • Spike testing – It tests the software’s response to sudden huge spikes in the load generated by users. This testing can be used to determine bottlenecks and the core capacity of the system
  • Endurance testing. This kind of testing is done to ensure that the software can handle the projected load over an extended period.
  • Volume testing –Also called flood testing, this form of testing is used to assess the app’s capability to handle huge volumes of data. This form of performance testing is critical for apps that deal with big data.
  • Scalability testing – The key objective of scalability testing is to identify the software app’s efficiency in “scaling up” to support an upsurge in user load. It involves calculating attributes counting throughput, Network usage, response time, CPU usage, hits and requests each second, transaction processing speed, and more.

Visual testing is also a crucial element of quality control and a prerequisite amongst industry-leading brands before releasing a new product or app update. Percy is one such effective visual regression test tool that can assist in expediting the UI test process by decreasing the test complexity. 


Try Percy Now

Preparation for UI Performance Testing

The UI performance test is crucial to ensuring the scalability, stability, and reliability of your applications that your customers expect. However, developing a comprehensive performance test strategy involves preparation, selecting, and implementing the types of performance testing, tools, and environment setup that are most relevant to your specific website/ applications.

Key Steps for UI Performance Testing:

1. Setting Objectives

The test plan or setting the objective is a key artifact of a well-executed performance testing strategy. It shows that a QA team has satisfactorily accounted for performance’s crucial role in the end-user experience. QA testers are then assigned to create test scripts for the particular flows/transactions with the specified date and prepare test scenarios with inputs such as numbers of virtual users, think time, appropriate ramp up/ramp down, pacing, etc.

2. Defining Key Performance Metrics

Performance testing metrics like average waiting time, error rate, CPU utilization, average load time, throughput, responses time, etc. are the parameters gathered during the load and performance testing processes. 

With the help of such metrics, performance QA teams determine the success of the performance tests process and further determine the critical areas in the software that requires more improvement/ attention. 

3. Tool Selection

It is critical to identify the types of performance testing and UI performance testing tools needed to give the go-ahead for production deployment. Ensuring that the QA testers have all necessary UI performance testing tools, frameworks, integrations, etc., is vital.

4. Test Environment Setup

Performance test environment setup and configuration is a vital step in the UI performance test strategy, which must be done with the utmost attention. Preparing the test environment as par with the production environment is supreme. Yet, most of the time, it’s not possible because of numerous reasons such as support resourcing, budget limitations, etc.

5. Debug and Re-Testing

Once test outcomes are in and bugs have been detected, sharing them with the whole team is necessary. Consolidate the glitches/ bugs and send them to the right developers to be fixed. When the performance shortcomings have been mitigated, re-run the UI Performance test to confirm that the code is appropriate/ clean and the software app performs optimally.

Best Practices for Performance Testing

  • Include Performance testing during the early phases of product development.
  • Take a DevOps Approach.
  • Incorporate automated performance tests into the CI/CD pipeline
  • Build a Complete UI Performance Model
  • Performance tests should cover all the relevant aspects of the product (i.e. third-party services, UI interactions, database interactions, and more) from a user performance standpoint. 
  • Consistently Report and Analyze the Results. Almost all the automated performance testing tools such as Apache JMeter, WebLOAD, LoadNinja, EggPlant, etc. have built-in reporting.
  •  It is crucial to leverage that feature to develop performance testing reports that can add value at every phase of the testing lifecycle. 
  • Keep your users at the forefront

Enhance your UI Performance with BrowserStack

UI is crucial for creating a better user experience. Let’s understand how to execute UI testing of an app or website. To ensure a flawless user experience, you can easily test the App across different real devices using BrowserStack App Live.

Step 1: Log in to BrowserStack App Live, & select any preferred Android or iOS real-time device.UI Testing of React Native Apps on Android and iOS devices 1536x748 1Step 2: Install the test app via any of the existing options. 

Step 3: Once the application is installed, log in to the same and run the test scenarios. QA engineers can scrutinize Android application efficiency and performance on actual devices with the BrowserStack cloud infrastructure without managing device labs. You can even upgrade the app settings as per your test requirements with the latest features, such as a testing camera, biometric authentication, and device passcode. It ensures the user experience is smooth and consistent across diverse devices and OS versions.  

With BrowserStack App Automate, you can simply automate the tests of mobile apps across 1000s of actual Android and iOS devices securely by integrating with varied testing frameworks like Appium,  CypressEspresso, etc.App automate

Test on Real Device Cloud


UI Performance testing is a crucial driver for enhanced user experience and overall customer satisfaction. As such, testers must make sure their application’s interface is simple to use and navigate, looks great across all devices and browsers, and, most importantly, it functions correctly.

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