Load testing: test the performance of your applications under stress

Ekara Load Test conducts both simple and complex load testing campaigns to assess the performance boundaries of your business software, websites, and mobile apps before go-live. Load testing reveals how your applications behave under stress, helping you deliver seamless digital experiences under pressure. Optimising application performance through rigorous load testing is key to maintaining high service quality and ensuring fast response times for end users.

Whether you’re a developer, system administrator, DBA, or project lead, Ekara load testing supports your performance goals at every level by providing detailed testing metrics and actionable insights to improve system response and stability.

What is load testing?

Watch an expert explain here what load testing entails, how the right testing tools are used, and what outcomes to expect from an effective testing strategy.

Load testing is essential when there are concerns over application performance issues and reliability during periods of stress — such as peak traffic, sudden spikes in user activity, or increased processing demands that can affect response times and system robustness.

Load testing is all about the digital experience of application performance

Application performance directly affects the user experience, impacting user satisfaction and conversion rates. Load testing helps detect performance issues like latency, lag, and system crashes before they degrade response times and affect your users. Through robust testing tools and simulated real-world traffic loads, testing ensures your applications stay stable, responsive, and resilient—even under stress.

Testing application performance under stress 

The goal of load testing is to evaluate how applications perform under intense usage. Advanced testing tools inject virtual users to stress the system and reveal how performance holds up:

• Identify how many concurrent users your platform can sustain before performance and response degrade

• Detect critical performance bottlenecks before they impact production environments

• Validate that your infrastructure meets required performance standards and response criteria

• Measure how performance shifts after updates or architectural changes

• Prevent failures during high-stress events or campaigns

Load testing delivers valuable insights into user experience across a range of real and simulated scenarios. You’ll gain clear answers to questions like:

• How does the application perform under normal versus heavy loads?

• What’s the traffic threshold before performance and response times degrade?

• How well will your business-critical applications perform under internal or external pressure?

For a forward-looking view on performance and load testing, see our tips for a successful load testing strategy. 

When to test application behaviour under load

There are strategic times and reasons to conduct load testing:

Events in website life cycles: in advance of seasonal sales  before major marketing campaigns prior to deploying a new website or new features	As part of the application life cycle: prior to launching new features or entire applications before rolling out each a new version
Quality practices (ITIL) change management capacity planning	Changes to the infrastructure/backend: virtualisation changes to the architecture to prevent regression during or after cloud migration

–> …and any time slowdowns or degraded performance issues arise under heavy traffic.

How to approach to load testing effectively

Effective load testing begins with a clear strategy. To deliver reliable performance insights, each phase of the testing process is structured:

• Select the right testing provider and tools to simulate user load and monitor response

• Define your testing objectives and performance benchmarks

• Create scenarios reflecting real-world user actions for accurate performance measurement

• Inject load to stress the application and observe behaviour and response

• Analyse performance and response results to locate weak points

• Share findings and actionable recommendations with your team

For more on how to make your load testing approach effective, read our Load Test white paper.

Simple or complex load testing tailored to your needs

To evaluate your system’s performance, Ekara offers two types of load testing, each using specialised testing tools:

Simple load tests

This type of testing is ideal for a fast assessment of performance thresholds. By progressively increasing the load on key user journeys, you can quickly pinpoint the first signs of stress and locate initial breaking points affecting performance and response.

Complex load testing

Complex testing replicates realistic user behaviours and traffic patterns. It includes various user profiles, stress scenarios, and simultaneous actions, providing a detailed performance picture under real-world conditions. Advanced testing tools simulate diverse usages and interactions for a richer understanding of platform resilience and response reliability.

Contact our experts to define your load testing strategy and choose the right tool. 

Applications compatible with Ekara Load Test

Our load testing service delivers end-to-end insights, testing and analyzing every level of the application delivery chain.  Our testing tools are designed to measure any kind of digital application, including thick-client and thin client (Citrix, for example) under heavy traffic in every type of environment, from HTTP web on the internet or intranet to VDI (virtual desktop infrastructure) and legacy applications.

• business software (ERP, CRM, etc.) and their architectures (middleware, databases, virtualization layers…)
• mobile applications (native or web)
• websites and e-commerce platforms
• APIs and web services
• SaaS and cloud applications

This testing capability also supports cloud migration strategies, measuring how well your applications run for end users before, during, and after the transition, helping ensure consistent performance and response times.

Explore more testing best practices and performance optimisation in our Load Test white paper.

Our load testing methodology

To test system limits accurately, we follow a five-step performance testing methodology:

• Needs analysis – identify stress scenarios and define performance objectives

• Scenario design – build realistic user journeys or scripts for testing

• Execution – run incremental load tests by injecting load using selected testing tools

• Results analysis – interpret performance data and pinpoint stress failures affecting response times

• Recommendations – suggest specific actions to improve capacity and performance

Advantages of load testing with Ekara

Recognised in the 2024 Gartner® Magic Quadrant, our solution offers key advantages:

• Testing tools cover multiple geographical locations across the globe

• Custom dashboards to visualise performance metrics

• Front-end testing of the entire application delivery chain to see into the user experience

• No-code configuration for quick script creation

• Trusted by 400+ clients across 25 countries

Also explore our Ekara Green offer for monitoring and optimising the environmental performance of your applications.

Customer case: Scaling up for seasonal sales success 

A leading retailer used our load testing solution to ensure their e-commerce platform was ready for the summer sales rush. With thousands of customers expected to shop simultaneously, performance under stress was critical.

Load testing revealed a bottleneck in the shopping cart feature, which began to fail when traffic reached 5,000 concurrent users. After targeted optimisation, the platform was retested and successfully supported 12,000 users without any performance degradation or slowed response times.

Thanks to early testing and data-driven improvements, the retailer delivered a smooth customer experience—and a successful high-traffic campaign.

Customer case: Securing website performance during cloud migration

A home furnishings e-retailer turned to a load testing specialist during its transition to a public cloud infrastructure. The goal: to ensure that the new environment could support customer traffic without compromising performance or response times.

The tests simulated real user behaviour and traffic peaks, enabling the team to validate the performance of the website under stress. The results confirmed that the migration objectives were met and that the new infrastructure could reliably handle visitor loads with optimal performance and response.

This type of performance testing is essential during any infrastructure migration—whether moving between physical servers, private virtual setups, or cloud environments (public, private, or hybrid). In this case, load testing gave the e-retailer confidence in the stability and response of their online platform post-migration.

Customer case: Validating virtual desktop performance for 300 concurrent users, with SLAs

An international transport company launched an IT consolidation initiative across all its French locations. As part of the project, its technology partner deployed a Citrix/VDI infrastructure to deliver core business applications—such as Lotus Notes, Microsoft Office, and Internet Explorer—via virtual desktops.

To ensure the new system could handle daily operations reliably, the company brought in a load testing provider. Simulated stress was applied, replicating the activity of 300 concurrent users to assess system performance.

The tests not only validated the infrastructure’s capacity but also provided critical insights for service monitoring. Three key performance indicators (KPIs) were defined based on real test data, forming the foundation of a new SLA strategy. Thanks to the load testing results, the company was able to set realistic and measurable SLA thresholds for ongoing service quality.

Customer case: Resolving performance issues after a Black Friday setback

During a recent Black Friday, a major sporting goods retailer experienced unexpected trouble: their website was unstable, and sales fell far below expectations. The platform appeared to function inconsistently, frustrating users at key moments in their shopping journey.

In response, the brand turned to a load testing specialist to investigate. Once key user journeys were mapped into testing scenarios, stress tests were launched to replicate peak shopping conditions. The testing revealed a critical issue: certain transactions were failing due to a bottleneck in the site’s search engine.

The culprit? A component that hadn’t been included in the pre-season performance testing. With this insight, the company was able to address the root cause and reinforce their system to better withstand future high-traffic events, improving overall performance and response.

Customer case: Optimising API performance for real-time service station data 

A major player in the oil and gas sector brought in a load testing expert to support the development of a new in-house API. This API was designed to allow various terminals to collect real-time data from the group’s service stations.

Rather than treating testing as a one-off event, the specialist tailored their approach to integrate directly with the customer’s internal development cycle. Working closely with the technical teams, the load testing expert helped adapt the API under real usage conditions—while it was live in production.

The result: ongoing performance improvements and a more robust API, capable of handling the stress of field conditions and diverse terminal requests.