Performance is a feature. A site that loads in two seconds converts better than one that takes eight. Here is how to test and improve web application performance.

What performance testing measures

It checks how your application behaves under load — response times, throughput, error rates, and resource usage when many users access it simultaneously.

Key metrics to track

Page load time, time to first byte, largest contentful paint, and server response time under load. Google's Core Web Vitals are a good starting benchmark.

Load testing vs stress testing

Load testing simulates expected traffic to confirm the app handles normal demand. Stress testing pushes beyond expected load to find breaking points.

Tools for the job

Tools like k6, JMeter, and Lighthouse help simulate load and measure performance. Use them in staging before testing production.

Common bottlenecks

Unoptimized images, missing caching, slow database queries, and unminified scripts are the usual suspects. Performance testing reveals which one is hurting you.

Test realistic scenarios

Simulate real user flows — browsing, searching, adding to cart, checking out — not just hitting the homepage repeatedly.

Set performance budgets

Define acceptable thresholds before testing. If checkout must respond in under two seconds with 100 concurrent users, test against that target.

Performance is ongoing

New features, traffic growth, and infrastructure changes can degrade performance over time. Re-test after major changes and monitor continuously.

The takeaway

Performance testing confirms your app handles real demand at acceptable speed. Test early, fix bottlenecks, and monitor after launch.

Hedztech includes performance testing in our QA process. See QA and testing services and web development, or book a consultation.