Load Testing Your API with k6

Overview

Load testing should answer concrete questions: where latency bends, which endpoints saturate first, and whether regressions are getting worse over time.

Baseline script

1import http from 'k6/http'
2import { check } from 'k6'
3
4export default function () {
5  const response = http.get('https://api.example.com/health')
6  check(response, {
7    'status is 200': (res) => res.status === 200,
8  })
9}

What to measure

• p95 latency
• error rate
• throughput under sustained load
• behavior under burst traffic

Summary

Useful load tests are small, repeatable, and tied to service objectives rather than vanity numbers.