Website Load Testing isn’t just for peak: Choosing the right test approach for the business risk

Website Load Testing is often associated with preparing for peak demand, but it can also reduce risk around re-platforming, major releases, campaigns, infrastructure changes and waiting-room configuration.

The key is designing a test plan that recreates the real-world scenario as closely as possible. That could mean benchmark, soak or spike testing, or a combination, depending on how traffic will arrive and how long demand will last.

Based on our experience testing business-critical platforms across multiple sectors, we explain how to choose the right test approach for the risk you need to address.

Whatever the scenario, testing should always reflect real customer behaviour, including traffic profiles, complete journeys, journey mix and drop-off, rather than simply applying an arbitrary number of concurrent users.

Types of Website Load Testing

1. Capacity benchmark testing gradually increases load to identify capacity and where performance starts to degrade.

2. Soak testing sustains load over time to check stability, expose issues that build over time and support configuration tuning.

3. Spike testing introduces a sudden traffic surge to see how the platform responds to concentrated demand.

1. Peak demand: can the platform handle peak traffic?

Before peak, you need to know not only whether the platform can support expected demand, but where performance starts to deteriorate, how key journeys are affected and how much headroom you have.

A capacity benchmark test gradually increases load to identify those limits. This is often followed by a short soak test to check that the target load can be sustained, not just reached.

2. Campaign traffic: what happens when demand arrives suddenly?

Email campaigns, promotions and launches can send large numbers of users to specific products or journeys within minutes.

A capacity benchmark test can establish capacity first, followed by a spike test to see how the platform responds to sudden demand.

This can expose autoscaling, caching and load-balancing issues where infrastructure does not have time to adjust to demand, perhaps due to incorrect configuration.

3. Waiting rooms: are you releasing traffic at the right rate?

A waiting room can protect a platform from a sudden peak, but optimising its configuration is critical. Hold users too long and you risk frustration; release them too quickly and you risk overwhelming the platform.

Load Testing can establish how much traffic the main platform can safely handle and help optimise the waiting room outflow rate, balancing shorter wait times with maximum safe throughput.

This can require a more complex test approach, combining spike, soak and capacity benchmark testing to reproduce the initial surge, sustained queue and controlled outflow onto the main platform.

We regularly use this approach for high-demand event and ticketing platforms, where the aim is to maximise throughput without compromising platform performance or customer experience. 

4. Infrastructure configuration: could the platform perform better?

Sometimes the issue is not a lack of capacity but how the infrastructure is configured. Autoscaling may trigger too late, caching may underperform or load balancing may distribute demand poorly.

Capacity benchmark testing establishes current behaviour, while a soak test provides consistent load for configuration optimisation. Teams can adjust settings during the test, measure the impact and identify the optimum configuration under realistic demand.

5. Major releases and integrations: will the change affect performance and customer experience?

A release may work perfectly from a functional point of view but behave differently when thousands of customers use it at once. New integrations can also introduce bottlenecks that are invisible at normal traffic levels.

A capacity benchmark test can establish how the changed platform performs as load increases, with soak or spike testing added where the release or integration creates a particular risk. This helps identify performance regressions and new bottlenecks before they affect customers.

6. Re-platforming: understand the new environment before customers do

A new platform brings  many unknowns, different capacity limits, scaling behaviour, caching rules and infrastructure configuration.

With less historical evidence to rely on, testing often needs to explore the environment more widely. A combination of benchmark, soak and potentially spike testing can help establish its behaviour, uncover configuration issues and build confidence before significant live traffic reaches it.

Soak testing can be particularly useful where configuration needs optimising, as teams can adjust settings under sustained load and measure the impact.

Start with the risk, not the test type

Benchmark, soak and spike testing are different ways of applying load to answer different questions. The aim is not to choose a test from a menu, but to recreate the real-world risk as accurately as possible.

Good Load Testing starts with the business risk, real customer behaviour and expected traffic pattern, then use the right combination of tests to prove capacity, validate change, optimise configuration and expose problems before customers experience them.

Peak may be the most obvious reason to Load Test. It is far from the only one.

Not sure which test approach you need?

Our fully managed Website Load Testing service includes expert test planning and delivery. We use your real traffic and journey data from Google Analytics to recommend the right combination of benchmark, soak and spike testing, design realistic trafic profiles and create yiou customer journeys then carry out the testing for you.

Talk to us about your next Load Test.