End-of-Test Summary

When a test finishes, k6 prints a summary of aggregated results to stdout. This summary provides a comprehensive overview of your test execution, organized by thresholds, checks, and metric categories.

Summary Modes

k6 provides three display modes through the --summary-mode option:

compact (default)
full
legacy

The compact mode displays the most relevant test results in a concise format, focusing on:

Threshold results
Check results
Aggregated metrics by category

k6 run script.js
# or explicitly
k6 run --summary-mode=compact script.js

Example output:

  █ THRESHOLDS

    http_req_duration
    ✓ 'p(95)<1500' p(95)=148.21ms
    ✓ 'p(90)<2000' p(90)=146.88ms

    http_req_failed
    ✓ 'rate<0.01' rate=0.00%


  █ TOTAL RESULTS

    checks_total.......................: 90      13.122179/s
    checks_succeeded...................: 100.00% 90 out of 90
    checks_failed......................: 0.00%   0 out of 90

    ✓ test-api.k6.io is up
    ✓ status is 200

    CUSTOM
    custom_waiting_time................: avg=152.355556 min=120      med=141      max=684      p(90)=147.2    p(95)=148.8

    HTTP
    http_req_duration..................: avg=140.36ms   min=119.08ms med=140.96ms max=154.63ms p(90)=146.88ms p(95)=148.21ms
      { expected_response:true }.......: avg=140.36ms   min=119.08ms med=140.96ms max=154.63ms p(90)=146.88ms p(95)=148.21ms
    http_req_failed....................: 0.00%  0 out of 45
    http_reqs..........................: 45     6.56109/s

    EXECUTION
    iteration_duration.................: avg=152.38ms   min=119.37ms med=141.27ms max=684.62ms p(90)=147.11ms p(95)=148.39ms
    iterations.........................: 45     6.56109/s
    vus................................: 1      min=1       max=1
    vus_max............................: 1      min=1       max=1

    NETWORK
    data_received......................: 519 kB 76 kB/s
    data_sent..........................: 4.9 kB 718 B/s

The full mode includes everything from compact mode plus:

All HTTP timing metrics (blocked, connecting, TLS handshaking, sending, waiting, receiving)
Group-specific results
Scenario-specific results

k6 run --summary-mode=full script.js

This mode is useful when you need detailed breakdowns by scenario or group, or when you want to see all HTTP timing phases.

The legacy mode uses the pre-v1.0.0 summary format for backward compatibility.

k6 run --summary-mode=legacy script.js

Use this mode if you have tooling that depends on the old format.

Understanding the Summary

Thresholds Section

Thresholds appear at the top of the summary with clear pass/fail indicators:

✓ Indicates a passing threshold
✗ Indicates a failing threshold

Each threshold shows its expression and the actual value:

http_req_duration
✓ 'p(95)<1500' p(95)=148.21ms
✗ 'p(99)<500' p(99)=687.43ms

If any threshold fails, k6 exits with a non-zero status code, making it perfect for CI/CD pipelines.

Checks Section

Checks show pass/fail ratios for assertions in your test:

checks_total.......................: 90      13.122179/s
checks_succeeded...................: 100.00% 90 out of 90
checks_failed......................: 0.00%   0 out of 90

✓ test-api.k6.io is up
✓ status is 200

Unlike thresholds, failed checks do not cause k6 to exit with an error. They’re for informational purposes.

Metrics by Category

Metrics are organized into categories based on their source: CUSTOM - Your custom metrics using Trend, Counter, Gauge, or Rate HTTP - Metrics from the k6/http module:

http_req_duration - Total request time
http_req_blocked - Time waiting for a free connection slot
http_req_connecting - Time establishing TCP connection
http_req_tls_handshaking - Time performing TLS handshake
http_req_sending - Time sending request data
http_req_waiting - Time waiting for server response (TTFB)
http_req_receiving - Time receiving response data
http_req_failed - Rate of failed requests
http_reqs - Total number of requests

EXECUTION - Test execution metrics:

iteration_duration - Time to complete one full iteration
iterations - Total number of iterations completed
vus - Current number of active virtual users
vus_max - Maximum VUs allocated

NETWORK - Data transfer metrics:

data_received - Total data received
data_sent - Total data sent

Categories only appear when relevant. For example, browser metrics appear only when using k6/browser.

Customization Options

k6 provides several options to customize the summary output:

# Choose summary mode
k6 run --summary-mode=full script.js

# Disable summary
k6 run --no-summary script.js

# Select trend statistics
k6 run --summary-trend-stats="min,avg,max,p(95),p(99)" script.js

# Set time unit
k6 run --summary-time-unit=ms script.js

Available Options

Option	Description	Default
`--summary-mode`	Display mode: `compact`, `full`, or `legacy`	`compact`
`--no-summary`	Disable end-of-test summary	`false`
`--summary-trend-stats`	Statistics to show for Trend metrics	`avg,min,med,max,p(90),p(95)`
`--summary-time-unit`	Time unit for all values (s, ms, us)	Auto-detected

Custom Summary with handleSummary()

For complete control over the summary output, use the handleSummary() function in your test script:

import http from 'k6/http';
import { textSummary } from 'https://jslib.k6.io/k6-summary/0.0.2/index.js';

export const options = {
  vus: 10,
  duration: '30s',
  thresholds: {
    http_req_duration: ['p(95)<500'],
  },
};

export default function () {
  http.get('https://test.k6.io');
}

export function handleSummary(data) {
  return {
    'stdout': textSummary(data, { indent: ' ', enableColors: true }),
    'summary.json': JSON.stringify(data),
    'summary.html': htmlReport(data),
  };
}

function htmlReport(data) {
  const passed = data.metrics.http_req_duration.thresholds['p(95)<500'].ok;
  return `
    <!DOCTYPE html>
    <html>
      <head><title>k6 Test Report</title></head>
      <body>
        <h1>Test Results: ${passed ? 'PASSED' : 'FAILED'}</h1>
        <p>Duration: ${data.state.testRunDurationMs}ms</p>
        <p>Requests: ${data.metrics.http_reqs.values.count}</p>
        <p>P95: ${data.metrics.http_req_duration.values['p(95)']}ms</p>
      </body>
    </html>
  `;
}

The handleSummary() function:

Receives the complete metrics data object
Returns a map of {destination: content} pairs
Can output to stdout, stderr, or any file path
Allows multiple outputs simultaneously

For more details on custom summaries, see the Custom Summary documentation.

CI/CD Integration

The end-of-test summary is ideal for CI/CD pipelines:

name: Load Test
on: [push]
jobs:
  k6:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run k6 test
        uses: grafana/[email protected]
        with:
          filename: test.js
      # k6 exits with code 99 if thresholds fail

Next Steps

Custom Summary

Create fully customized summary reports with handleSummary()

Real-Time Output

Stream metrics during test execution for live monitoring

Thresholds

Learn how to define performance requirements with thresholds

Checks

Understand how to add assertions to your tests

Using k6

Testing Guides

Browser Testing

Results & Visualization

End-of-Test Summary

End-of-Test Summary

Summary Modes

Understanding the Summary

Thresholds Section

Checks Section

Metrics by Category

Customization Options

Available Options

Custom Summary with handleSummary()

CI/CD Integration

Next Steps

Custom Summary

Real-Time Output

Thresholds

Checks

Build docs developers (and LLMs) love

Using k6

Testing Guides

Browser Testing

Results & Visualization

​End-of-Test Summary

​Summary Modes

​Understanding the Summary

​Thresholds Section

​Checks Section

​Metrics by Category

​Customization Options

​Available Options

​Custom Summary with handleSummary()

​CI/CD Integration

​Next Steps

Custom Summary

Real-Time Output

Thresholds

Checks

Build docs developers (and LLMs) love

End-of-Test Summary

Summary Modes

Understanding the Summary

Thresholds Section

Checks Section

Metrics by Category

Customization Options

Available Options

Custom Summary with handleSummary()

CI/CD Integration

Next Steps