What is performance testing?

Performance testing checks how fast, stable and scalable your software is under realistic and extreme load. It answers questions such as how many users you can handle, how fast pages and APIs respond at peak, and what breaks first.

What is the difference between load and stress testing?

Load testing holds the traffic you expect and checks you meet your targets. Stress testing keeps adding load beyond that until something fails, so you know your real limit, what fails first and how the system recovers.

What is endurance or soak testing?

Endurance testing, also called soak testing, runs steady load for many hours to find problems that only appear over time, such as memory leaks, slow drift in response times and growing queues or logs.

When should we run spike testing?

Before anything that can send a sudden rush of users: a sale, a ticket release, a push notification, a live event or a marketing campaign. It shows whether autoscaling and caches react in time.

How many users can you simulate?

As many as your test needs. Load comes from cloud load generators, so we size it to your expected peak plus headroom, from a few hundred users to very large audiences.

Which tools do you use?

JMeter and k6 most often, plus Gatling, Locust, LoadRunner, NeoLoad, BlazeMeter and Artillery. For monitoring we use Grafana, Prometheus, InfluxDB, Datadog, New Relic, Dynatrace, AppDynamics and Elastic. We can also work in the tools you already have.

Can you test in production?

We usually test in a production-like environment. Carefully planned tests in production are possible, outside busy hours and with clear limits and rollback, when no other environment is realistic.

What results will we get?

Response times, throughput and error rates for each journey and load level, your system’s limits, the bottlenecks found with their cause, and a list of fixes ranked by user impact and effort.

Do you help fix the bottlenecks?

Yes. We trace each slow response to a cause, such as a query, a connection pool, a cache or a third-party call, work with your developers on the fix and retest with the same load to prove it worked.

How do you decide on targets?

From your analytics, your business goals and any agreements you have with customers. Typical starting points are page and API response times at the 95th percentile and a maximum error rate, which we agree with you before the first run.

Can performance tests run in our CI/CD pipeline?

Yes. Short performance checks can run on every build in Jenkins, GitHub Actions, GitLab CI or Azure DevOps, with budgets that fail the build if response times get worse.

Do you test mobile app performance?

Yes. We load test the APIs and services behind your app, and check app start time, screen speed, battery and data use on real devices and slower networks.

How long does a performance test take?

A focused load test on a few key journeys usually takes one to two weeks, including modelling, scripting, runs and reporting. Larger programmes with soak and scalability runs take longer.

How do we get started?

Book a call or send the form on this page. We start with a free one-week proof of concept on your most important journey, so you can see real results before you commit.

Performance Testing

Trust our Performance Testing expertise to optimize your software, and improve performance and CX.

Know exactly how your system behaves before your users find out. We recreate real traffic, find the limits and trace every slowdown to its cause, so busy days feel like any other day.

Get in touch Plan your load test

6 test types
JMeter, k6 and more
Bottlenecks traced to a cause
Free one-week POC

Jump to a test type

Load TestingExpected traffic Stress TestingPast the limit Spike TestingSudden surges Endurance (Soak) TestingLong runs Scalability TestingGrowth ahead Volume TestingBig data sets

[ Why performance testing ]

Uplift your digital experience through performance testing

QAonTOP’s performance testing assesses your system’s speed, scalability, and stability against high traffic loads. We identify potential performance bottlenecks with creative test scenarios for extreme conditions, ensuring your system performs well during high-traffic events like Black Friday or New Year’s Eve.

Optimize software performance for reliability and exceptional user experiences.
Identify and resolve bottlenecks to enhance responsiveness and customer satisfaction.
Future-proof your software for scalability amid increasing user demands.
Drive cost efficiency by proactively addressing performance issues in early stages.

Performance testing that answers business questions. You get numbers tied to user experience and a prioritised list of fixes, not a wall of graphs.

Enhanced User Satisfaction

Performance testing guarantees efficient software with seamless user experience, stability, and responsiveness.

Cost Optimization

Achieve cost-effective solutions with performance testing that identifies inefficiencies, optimizes resource use, and enhances system performance for savings.

Optimized Server Load

Performance testing finds and fixes bottlenecks, improving server load efficiency for better system performance.

Proactive Issue Resolution

Identifying performance issues before deployment allows for proactive fixes, preventing post-release problems and improving system reliability.

Improved Business Scalability

Effective performance testing services enhance scalability, helping your system handle future demands and ensuring business growth.

Software Stability

Comprehensive performance testing guarantees software stability and high performance for critical events.

[ Under load: from baseline to breaking point ]

Get Speed and Scale with Effective Performance Testing

We assess system capacities for a range of software products, from lightweight HTML sites to complex JavaScript applications and REST APIs. QAonTOP selects the load profile that answers your question, whether that is peak readiness, endurance, or recovery.

Load Testing

Expected traffic

View service

Simulate real-world traffic to identify how your website handles concurrent users, pinpointing issues for optimal performance.

We build the load from your real traffic: how many people arrive, what they do and how long they stay, then hold it steady and watch every layer.

What we measure

Response times at the 95th and 99th percentile
Throughput and error rate per journey
Server, database and cache use
Pass or fail against agreed targets

When you need it

Before every launch, campaign or major release.

Typical run

30–60 minutes at expected peak, after a gradual ramp-up

Risk it preventsSlow pages and timeouts at normal busy times

Stress Testing

Past the limit

View service

Tests application’s performance and stability under extreme resource and load conditions.

We keep adding load until something gives, so you know your real ceiling, what fails first and whether the system recovers on its own.

What we measure

The breaking point in users and requests per second
Which component fails first
Error handling and graceful degradation
Recovery time once load drops

When you need it

Before peak season, and whenever architecture changes.

Typical run

Step-ups of 10–25% until the system fails, then recovery

Risk it preventsCrashes and data loss when demand outgrows capacity

Spike Testing

Sudden surges

View service

Simulate user activity bursts to assess software responsiveness and performance.

A flash sale, a push notification or a TV mention can multiply traffic in seconds. We recreate that surge and see whether you scale in time.

What we measure

Response times during the first minutes of a surge
Autoscaling speed and warm-up
Queues, rate limits and caches under pressure
How fast things settle afterwards

When you need it

Before sales, ticket drops, live events and marketing pushes.

Typical run

Jumps of 3–10× normal load within seconds, repeated

Risk it preventsOutages in the first minutes of a big moment

Endurance (Soak) Testing

Long runs

View service

Assesses system performance and stability over extended periods of continuous use.

Some problems only show up after hours. We run steady, realistic load for a long time to find leaks, slow drift and growing queues.

What we measure

Memory and connection leaks
Response times drifting over time
Log, disk and queue growth
Scheduled jobs running under load

When you need it

Before go-live of always-on systems, and after big upgrades.

Typical run

8–24 hours at normal load

Risk it preventsSlowdowns and crashes after days in production

Scalability Testing

Growth ahead

View service

Checks the system’s effectiveness under increasing traffic, transactions, and data volumes.

We measure what each extra server, instance or database node really buys you, so you can plan growth and cloud spend on evidence.

What we measure

Capacity gained per added node or instance
Autoscaling rules and limits
Where scaling stops paying off
Cost per user at each level

When you need it

Before growth plans, new markets and cloud budget decisions.

Typical run

Several runs at rising load and infrastructure sizes

Risk it preventsPaying for capacity that doesn’t help

Volume Testing

Big data sets

View service

Measures app performance under high data volumes and many users simultaneously.

Fast with a test database is not the same as fast with years of real data. We load realistic volumes and test the queries and reports that depend on them.

What we measure

Query and report speed on large tables
Indexes, locking and storage growth
Imports, exports and batch jobs
Search and pagination at scale

When you need it

Before migrations, big customer onboarding and reporting launches.

Typical run

Production-sized data, or 2–5× it for future growth

Risk it preventsReports and searches that grind to a halt as data grows

[ Where we measure ]

Our testing supports different platforms

From the page a customer opens to the database and services behind it, we load test every layer that can slow your product down.

Web applications

Simulate user actions on web pages to measure application performance and stability.

Simulate the way user interacts and takes action on web pages.

Mobile app

Assess mobile apps across devices and networks for optimal functionality and efficiency.

Test the performance of your app on different devices and networks.

API & Web services

Evaluate API and web service performance with automated requests under load.

Send automated requests to assess the response time and stability under load.

Cloud Services

Measure cloud services' performance by simulating user loads and analyzing results.

Easily simulate user load on applications which are hosted on cloud.

Databases

Query profiling, locking, and connection pool limits.

Slow queries found while real load is running, not after.

Third-party services

Impact of external dependency latency and timeouts.

Payment, maps, email and other services you don’t control, tested for what happens when they slow down.

[ What we measure ]

Eliminate errors to safeguard software performance

As application interactivity and user requests increase, server load grows and demands higher service levels. Performance testing is essential to ensure your app functions well under real conditions, helping to detect slow loading times, response delays, scalability issues, and more.

Efficient Resource Utilization
Bottleneck Identification
Optimize App Performance
Peak Load Preparation
Reliability and Availability
Response Time Compliance

The numbers in every report

Response time (p95, p99): How long the slowest 5% and 1% of users wait. Averages hide the people having a bad time.
Throughput: Requests or transactions handled per second at each load level.
Error rate: Failed requests and timeouts as load rises.
Concurrency: How many users are active at once when things start to slow.
CPU, memory and I/O: Where each server runs out of room first.
Database time: Slow queries, locks and connection pool limits under load.

[ Load testing ]

Planning a load test? Start with your busiest day

Load testing has its own page: the eight load testing services we offer, how load testing differs from stress, spike and soak tests, and a five-question planner that turns your traffic into a test plan with starting targets.

Plan your load test Load testing services

Peak-load and headroom runs
Website, API and database load
Third-party services under load
Cloud capacity and autoscaling
Launch and campaign readiness
Load checks in your CI/CD pipeline

[ Result Driven Process ]

A process built on solid foundation

We define workload models from real traffic, build scripts that reflect actual journeys, run against a production-like environment, and profile the stack while load is applied so bottlenecks are identified, not guessed.

Step 1 of 6
Workload modelling

We turn your analytics and business goals into a model of real users: who arrives, what they do and how fast.

You getWorkload modelAgreed targets
Step 2 of 6
Environment readiness

A production-like environment, test data and monitoring in place before the first run.

You getEnvironment checklist
Step 3 of 6
Script development

Scripts that follow real journeys, with realistic data, think times and sessions.

You getTest scripts you own
Step 4 of 6
Load execution

Baseline, load, stress, spike and soak runs, each one answering a clear question.

You getRun results
Step 5 of 6
Bottleneck profiling

Servers, database and network profiled while the load is applied, so causes are found, not guessed.

You getBottleneck report
Step 6 of 6
Tuning and retest

Fixes checked with the same load, and performance budgets added to your pipeline.

You getBefore-and-after reportCI performance checks

Free one-week POCWe load test your most important journey for a week, so you can judge our work first.
Scripts and results are yoursEvery script, workload model and dashboard is handed over, ready to run again.
Safe by defaultNDA first, synthetic data, agreed run windows and a stop button for every test.

[ Tools ]