How to Stress Test a Website?

Most business owners remember load testing only once a year — the week before "Black Friday". Usually, this ends with the site crashing in the first second of the sale. Stress testing in 2026 is not a one-time event, but part of the CI/CD process.

Anatomy of a Slowdown: What Are We Looking For?

Your system is a chain. And it will break at the weakest link. Database, slow third-party API, full connection pool — there is always a "bottleneck". Our task is to find it BEFORE real users do.

Three Main Test Types

Many confuse these concepts, but the difference is critical:

• Load Testing: "Will the site withstand the expected load?" (e.g., 1000 users). Goal — to verify SLA compliance.
• Stress Testing: "Where is the breaking point?" We increase the load until the server crashes. This is needed to know the safety margin (Capacity Planning).
• Soak Testing (Endurance): "What happens after 24 hours?" Reveals memory leaks that are not visible in short tests.

Tools of 2026

Forget manual scripts. We use industrial standards:

1. k6 (Grafana Labs): The modern standard. JS scenarios, native Grafana integration. Ideal for developers.
2. Apache JMeter: The "grandfather" of load testing. Complex GUI, but can do everything. Good for enterprise.
3. Locust: Python code. Easy to write, easy to scale in the cloud.

NineLab Tip: Don't test in a vacuum. Your bots should behave like people: browse the site, add items to cart, use search. Just "hammering" the main page is useless.

Summary: Don't wait for an incident. Conduct a stress test today to sleep well tomorrow. Forewarned is forearmed.