Before you even start setting up your load tests, it’s crucial you establish your objectives. No site or app can maintain lightning-fast speeds while at or close to capacity. Load testing involves testing software’s performance with a specified load to understand how it behaves under expected or heavy usage. It’s a type of performance test that investigates the speed, scalability, and reliability of a system.

what is load testing

Load testing is especially important if the application, system, or service will be subject to a service level agreement or SLA. Essentially, it can handle the massive traffic peaks high-visibility events attract, so you and your engineering team don’t have to. It runs on robust and highly scalable cloud-hosted infrastructure that handles some of the world’s biggest online events.

Load testing tools

Stress testing, on the other hand, is applied to check how the system behaves beyond normal or peak load conditions and how it responds when returning to normal loads. A load test can be done with end-to-end IT systems or smaller components like database servers or firewalls. It measures the speed or capacity of the system or component through transaction response time. When the system components dramatically extend response times or become unstable, the system is likely to have reached its maximum operating capacity. When this happens, the bottlenecks should be identified and solutions provided. Simulate the expected load, the capabilities you are testing, test frequency, ramp-up, and any other part of the scenario.

  • A few examples are slow database queries, loop conditions that can seriously impact performance under load, and infrastructure issues.
  • Some load testing platforms will let you measure time between actions, such as button clicks, and provide the resulting data on the screen, while other systems can only measure the total time it took to complete a script.
  • If the open circuit voltage is below spec (12.6 volts for a fully charged battery), the battery is charged first.
  • Put differently, load testing goals (which are often not given enough thought), will depend on the context and specific business.
  • A methodological and well-documented process that is planned and based on pre-defined goals can save lots of time.

These queries can significantly slow down the application, negatively impacting user experience. To address this issue, Service Level Agreements (SLAs) are established for critical transactions, specifying certain performance criteria that need to be met. Load tests help determine if the application violates these predefined performance values when subjected to different loads. Getting started with load testing isn’t as hard as it has been historically.


The performance of the system or application is tested and analyzed to ensure that it meets the performance requirements. However, at some point you will see that while you are adding more and more virtual users, the number of requests per second remains the same or even goes down due to increased response time. Bottlenecks can happen during this stage with errors and even stop serving incoming requests entirely. The specifics of a load test plan or script will generally vary across organizations.

Load Testing ensures that your application can perform as expected in production. Just because your application will pass a functional test, this does not mean that it can perform the same under a load. Load testing identifies where and when your application breaks, so you can fix the issue before shipping to production.

The process of running load testing

One thing to remember about JMeter is that it operates at the protocol-level only. This means that if you are looking to carry out performance tests that include client-side interactions, JMeter is not the tool for this job. Additionally, since JMeter must be installed on a local device, you can only scale your tests to a certain point.

what is load testing

Access to multiple devices helps you predict and handle issues before your product reaches production. BrowserStack Automate provides access to an array of web browsers and OS for you to test your applications. Performance testing tools are platforms that evaluate and analyze the speed, scalability, robustness and stability of the system under tests.