Website and Web App Performance Testing and Optimization Guidelines

By Staff Contributor on October 8, 2020

Website and web application users in the digital era have no patience for slow or unreliable websites and applications. With plenty of competing options out there, a user is unlikely to stay on your website if it isn’t performing to their expectations—which is why it’s important companies conduct appropriate web application testing and website performance testing.

This guide will explain performance testing, provide a brief history of how it has developed, and outline the most important web application testing and website performance testing optimization guidelines. If you’re looking for a website and web app performance testing solution to help you simplify and enhance your performance testing strategy, we recommend SolarWinds® Web Performance Monitor (WPM). WPM is a user-friendly and sophisticated website monitoring solution built to find and help you fix both internal and external site and app performance issues. This tool is scalable, cost-efficient, and gives you detailed insight into performance testing metrics. A 30-day free trial is available.

What Is Performance Testing?
The History of Performance Testing
The Importance of Web Application Testing Today
Key Types of Website Performance Testing
Website Performance Testing Guidelines

What Is Performance Testing?

Website performance testing and web app performance testing assess your site’s efficiency in comparison to its specifications. The key focus of website performance testing is to determine the overall responsiveness and performance under average loads. This type of testing should be performed early and often to uncover any potential imbalances in the software architecture or its implementation.

As an example, website performance testing and web app performance testing might uncover the monopolization of resources or unexpected latency. Both issues are easier to correct in the early stages than the later stages of development or testing.

The result of these performance tests and subsequent modifications is to create a set of baseline measurements or performance testing metrics. These baselines are then applied whenever the website or web app is changed, to ensure the processing efficiency and responsiveness are preserved and improved.

The History of Performance Testing

Professional software development has evolved enormously over the past few years. Just a couple of decades ago, when the web was in its infancy, hand-coding PHP or PERL live on a production machine was fairly commonplace. While now that might seem like poor judgment, at the time the stakes were far lower. This was, in part, because a few minutes of site downtime didn’t necessarily spell disaster during the early days of the internet.

Because the stakes were lower, web developers had much less reason to install pre-production verification processes. Instead, most web developers relied on trial and error—they made a change and would wait to see if an issue occurred. Anything the web developers missed would undoubtedly be flagged by the end user.

Of course, web application testing has evolved since then. As soon as e-commerce gained some momentum in the web development world, stakes became significantly higher. While amateurs might have taken risks on production edits, professional shops and developers began to create and test in development or sandbox environments.

Web development then took another step as automation became integrated into the testing strategy. Shops ahead of the curve at this time had their QA environments as a check on production releases, but their developers also began to create automated test suites. These automated test suites were used to protect against regression tests and to ensure the web application was performing as it should be.

As web application testing matured beyond basic unit test suites and record-playback-style integration tests, companies started to become familiar with the test pyramid. This allowed them to build increasingly advanced, nuanced test suites.

The Importance of Web Application Testing Today

In recent years, there has been a rise in the DevOps movement, emphasizing the importance of automating the entire delivery pipeline—from written code to production functioning. Stakes for automated testing are higher than ever, and the only way to automate the complete pipeline is to use infallible verification methods.

Today, developers can push code through build, test, and deployment effectively—but still can’t be entirely certain how code will behave once it’s fully launched. Web app performance testing is the solution to this problem, which is why it’s a crucial part of any testing strategy.

Put simply, if your website or web app doesn’t perform optimally, customers who have become accustomed to speed will be less likely to choose your business. When you lose customers, you lose business—usually to your competition. This means a poorly performing website or web application will cost you, either indirectly or directly. Fortunately, with effective website and web app performance testing, you can eliminate poor performance and reap the following benefits.

  1. Measure Speed, Stability, and Endurance

Measuring the speed, stability, and endurance of your website or web application is a crucial part of successful performance testing. With the right testing techniques and tools, you can ensure your website or web app is fast enough to meet user expectations and durable enough to cope under the most extreme pressure and stress. Web application load testing and website speed testing plays a key part in this, giving developers the insight they need to optimize performance.

  1. Customer Satisfaction

The first impression you make on prospective customers is essential, with research showing more than 50% of users expect web and mobile-based applications to load in less than two seconds. By measuring application performance, you can gain valuable insight into how your customers are responding to your software. This also gives you the chance to identify critical problems before they impact your customers. With thorough performance testing, you don’t have to wait for customer complaints to roll in before making a change—you can take preemptive action, based on your tests, to keep customers happy.

  1. Identify Discrepancies and Resolve Problems

Measuring and monitoring performance provides an important buffer for developers before they release their website or web application. Any issues are likely to be magnified once they’re released, but performance testing gives you the chance to iron out any issues before launch. This protects your company’s reputation by reducing the likelihood of something going drastically wrong.

Effective testing allows for more time to be spent on improving technology and strategy, rather than solving avoidable issues. Keep in mind when left unaddressed, problems are likely to grow exponentially and become increasingly expensive once a website or web app has already been launched.

  1. Improve Optimization and Load Capability

Another important benefit of performance testing is the ability to improve optimization and load capacity. Testing performance can help your business manage volume, so your website or web application can cope at peak usage. Prior testing allows you to optimize performance and tailor capacity to handle spikes in demand. This means your business can manage scalability more effectively.

Key Types of Website Performance Testing

Load testing a website and website speed testing are two key types of website and web app performance testing. Web application load testing, or load testing a website, refers to the process of simulating thousands or even millions of users over long periods of time. This provides an effective way of determining whether your websites or web applications have enough endurance and volume capacity. Load testing can help you uncover buffer overflows, responsiveness degradation, and memory leaks.

It’s not a matter of load testing vs. performance testing, but rather that load testing should play a key role in your wider performance testing strategy. Website speed testing usually walks hand in hand with load testing and focuses on identifying areas on your website or web application likely to be slowing it down.

Stress tests are another important type of website performance testing. Stress testing involves applying maximum burden on a website to uncover its breaking points. These tests also measure how successfully your site crashes and recovers. If the site can fail without losing data or creating security risks and can recover quickly with minimal disruption to end users, then the stress test is successful.

There are several other types of performance test that can be conducted, including the following:

  • Performance Test: Although the term “performance testing” can be used generically, it also specifically applies to tests for the responsiveness, speed, and scalability of a website or web app
  • Capacity Test: This test is conducted to ensure a certain number of users/transactions can be supported at a given time
  • Endurance Test: An endurance test is conducted to ensure the system will be able to handle the expected load for a long period of time

Website Performance Testing Guidelines


As you start performance testing a website or web application, it’s key you understand the following:

  • The purpose of the website or web app (i.e., payment gateways, web services, etc.)
  • The reason for performance testing—we recommend making a list of what you would like to test/measure (i.e., testing for number of users, volume testing, response time testing, etc.)
  • The customer’s expectations
  • The project schedule and the QA window
  • The availability of resources and QA tools

We’d also recommend creating a checklist of your performance analysis criteria. This might include the following:

  • The acceptable time between transactions/user clicks
  • The expected average session duration of a user
  • The acceptable page load time
  • The current baselines available to measure against (if applicable)
  • The analytics tools used to identify high volumes

Once you’ve accounted for these considerations, it’s time to start performance testing. The following guidelines will help you avoid some common pitfalls associated with website performance testing, so you can ensure your web applications and websites are performing as expected.

  1. Maintain Up-to-Date Test Infrastructure

It’s important you keep your in-house test infrastructure up to date. The test infrastructure serves as your baseline environment for isolating testing side effects—which will significantly reduce the amount of time it takes to successfully conduct root cause analysis for a range of issues.

  1. Use Your Live Site

If you have an existing live site, you should use it to guide load and stress parameters on the developing site. As an example, an initial test load might be the number of actual peak-hours orders multiplied by your expected growth rate, plus 20% overhead.

  1. Track Client and Server-Side Traffic

We recommend tracking both client and server-side traffic during peak and non-peak performance testing. This will help you determine accurate rations between traffic and processing activities, which often uncovers imbalances.

  1. Test Comprehensively

To make the most of performance testing, make sure you’re testing as many pages and combinations of page traversals as possible. Measure single-page and page-combination load times, right down to the component level. This will give you broad and detailed insight, ensuring little is left to chance.

  1. Pay Attention to Time Consumption

Keep a close eye on which pages or activities are consuming a significant amount of time, in relation to other areas of the website or web application. This will help you optimize how your performance tests are used as you repair resources.

  1. Distribution

Make sure you distribute generated loads both geographically and by network segment. This plays a key role in the overall success of your web app and website performance testing strategy.

  1. Monitor Dependency

A common performance testing pitfall is ignoring the dependency between page load times and user volume capacity. To avoid this, measure both aspects at every stage of the testing process.

  1. Process Live Web Traffic Logs

Another often overlooked aspect of performance testing is processing live web traffic logs. This allows you to collect key performance testing metrics and statistics on the types and volume of requests coming into your site. This information can then be used to optimize load testing.

  1. Prioritize Perceived Load Time

Once you understand website and web app performance is key to a great user experience, you will recognize the user’s perceived load time should be a top priority for every business.

Load time is one of the most important performance metrics available. The following statistics will demonstrate how important it is your web app or website loads almost instantaneously:

  • Under 100 milliseconds is generally perceived as being instantaneous
  • A 100-millisecond to 300-millisecond delay is perceptible to users
  • One second is the limit for the user’s flow of thought to remain uninterrupted
  • Users expect a website or web app to load within two seconds
  • After three seconds have passed, 40% of users will leave your website or web application
  • Ten seconds is around the limit for maintaining the user’s attention

As these figures show, most users expect an instant response from the websites and web applications they use. For your web app or website to have a chance of holding their attention, you’ll need to ensure your performance testing strategy is thorough and dependable.

  1. Use a Performance Testing Tool

SolarWinds Web Performance Monitor (WPM) offers complete performance monitoring, allowing you to monitor both web and SaaS application performance. This solution gives you insight into whether slow web services are affecting user experience and features continuous synthetic transaction monitoring, allowing you to experience your app like a user.

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With detailed load time metrics, WPM helps you identify and resolve slow webpage elements affecting overall performance. This tool also helps you diagnose latency issues. Another useful WPM feature is regular expression text matching—which allows you to expand synthetic end-user monitoring capabilities by matching any regular expression (regex) to an entire line or a block of complete lines.

WPM includes a responsive design allowing users to set specific resolutions in the web transaction recorder to emulate different device screens, meaning you can monitor the associated user experiences. This website performance testing tool also features tab handling, which provides a smoother testing experience for users when an action within a web transaction causes a new browser tab to open.

This web app performance testing tool is highly advanced, allowing you to proactively address website speed and performance issues before end users are affected. You can examine every aspect of your webpage and rapidly troubleshoot issues, and test website speeds from anywhere to determine if the page is loading slowly in general or if it’s isolated to a specific location.

WPM can be used to monitor website user experience on-premises or in the cloud. It gives you maximum visibility across the application stack. This means you can map the relationship between a transaction to its supporting servers, databases, virtual infrastructure, and storage resources.

SolarWinds WPM is a versatile and sophisticated performance testing solution that is easy to use and suitable for companies anticipating growth. It’s designed to scale with you and is ideal for small and large companies alike. A free 30-day trial is available for download.

Getting Started With Performance Testing

The performance of your website or web app will contribute to user satisfaction and to the success of your organization. Sadly, website and web app performance testing can be a time-consuming process. Mistakes can be costly and have a negative impact on your company’s reputation if your website or web app is launched without thorough testing. Fortunately, performance testing activities are made significantly easier by the right performance testing tools. If you’re looking for a scalable, enterprise-grade, user-friendly performance testing tool, we highly recommend SolarWinds WPM.

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