Environment Variables

Environment variables supported by k6

Environment Variables

k6 supports configuration through environment variables, which provide an alternative to CLI flags and are particularly useful in CI/CD environments.

Precedence

Configuration sources are applied in this order (later overrides earlier):

1. Script options (export const options = {})
2. Configuration file (k6.json)
3. Environment variables
4. CLI flags (highest priority)

Runtime Environment Variables

K6_TYPE

K6_TYPE · string

Override test type detection.

Values: js, archive

K6_TYPE=js k6 run test.txt

K6_INCLUDE_SYSTEM_ENV_VARS

K6_INCLUDE_SYSTEM_ENV_VARS · boolean · default: "false"

Pass system environment variables to the script runtime.

K6_INCLUDE_SYSTEM_ENV_VARS=true k6 run script.js

K6_COMPATIBILITY_MODE

K6_COMPATIBILITY_MODE · string · default: "extended"

JavaScript runtime compatibility mode.

Values: extended, base, experimental_enhanced

K6_COMPATIBILITY_MODE=base k6 run script.js

Output and Summary Variables

K6_OUT

K6_OUT · string[]

Metrics output destinations (comma-separated).

K6_OUT="json=results.json,influxdb=http://localhost:8086" k6 run script.js

K6_NO_SUMMARY

K6_NO_SUMMARY · boolean

Disable the end-of-test summary.

Deprecated: Use K6_SUMMARY_MODE=disabled instead.

K6_NO_SUMMARY=true k6 run script.js

K6_SUMMARY_MODE

K6_SUMMARY_MODE · string · default: "compact"

Summary display mode.

Values: compact, full, disabled, legacy (deprecated)

K6_SUMMARY_MODE=full k6 run script.js

K6_SUMMARY_EXPORT

K6_SUMMARY_EXPORT · string

Export summary to a JSON file.

K6_SUMMARY_EXPORT=summary.json k6 run script.js

K6_NO_THRESHOLDS

K6_NO_THRESHOLDS · boolean

Disable threshold execution.

K6_NO_THRESHOLDS=true k6 run script.js

Test Execution Variables

K6_LINGER

K6_LINGER · boolean

Keep the API server alive after test completion.

K6_LINGER=true k6 run script.js

K6_NO_USAGE_REPORT

K6_NO_USAGE_REPORT · boolean

Disable anonymous usage statistics.

K6_NO_USAGE_REPORT=true k6 run script.js

K6_WEB_DASHBOARD

K6_WEB_DASHBOARD · boolean

Enable the web dashboard.

K6_WEB_DASHBOARD=true k6 run script.js

Tracing Variables

K6_TRACES_OUTPUT

K6_TRACES_OUTPUT · string · default: "none"

Distributed tracing output configuration.

Values: none, otel, otel=host:port

K6_TRACES_OUTPUT=otel=localhost:4317 k6 run script.js

SSLKEYLOGFILE

SSLKEYLOGFILE · string

File to write TLS master secrets for decrypting traffic.

SSLKEYLOGFILE=/tmp/sslkeys.log k6 run script.js

Cloud Variables

K6_CLOUD_TOKEN

K6_CLOUD_TOKEN · string

Grafana Cloud k6 authentication token.

K6_CLOUD_TOKEN=your_token k6 cloud run script.js

K6_CLOUD_HOST

K6_CLOUD_HOST · string · default: "https://ingest.k6.io"

Grafana Cloud k6 API host.

K6_CLOUD_HOST=https://custom.k6.io k6 cloud run script.js

K6_CLOUD_PROJECT_ID

K6_CLOUD_PROJECT_ID · int

Project ID for organizing cloud tests.

K6_CLOUD_PROJECT_ID=12345 k6 cloud run script.js

K6_CLOUD_STACK_ID

K6_CLOUD_STACK_ID · int

Stack ID for Grafana Cloud instance.

K6_CLOUD_STACK_ID=12345 k6 cloud run script.js

K6_SHOW_CLOUD_LOGS

K6_SHOW_CLOUD_LOGS · boolean · default: "true"

Stream cloud test logs to terminal.

K6_SHOW_CLOUD_LOGS=false k6 cloud run script.js

K6_EXIT_ON_RUNNING

K6_EXIT_ON_RUNNING · boolean

Exit when cloud test reaches running state.

K6_EXIT_ON_RUNNING=true k6 cloud run script.js

K6_CLOUD_UPLOAD_ONLY

K6_CLOUD_UPLOAD_ONLY · boolean

Upload test to cloud without running it.

Deprecated: Use k6 cloud upload instead.

K6_CLOUD_UPLOAD_ONLY=true k6 cloud script.js

K6_NO_ARCHIVE_UPLOAD

K6_NO_ARCHIVE_UPLOAD · boolean

Disable archive upload in cloud run commands.

K6_NO_ARCHIVE_UPLOAD=true k6 cloud run script.js

Global Variables

K6_ADDRESS

K6_ADDRESS · string · default: "localhost:6565"

REST API server address.

K6_ADDRESS=localhost:8080 k6 run script.js

K6_CONFIG

K6_CONFIG · string · default: "./k6.json"

Path to configuration file.

K6_CONFIG=/path/to/config.json k6 run script.js

K6_LOG_FORMAT

K6_LOG_FORMAT · string · default: "text"

Log output format.

Values: text, json

K6_LOG_FORMAT=json k6 run script.js

K6_LOG_OUTPUT

K6_LOG_OUTPUT · string · default: "stderr"

Log output destination.

Values: stderr, stdout, or file path

K6_LOG_OUTPUT=/var/log/k6.log k6 run script.js

K6_NO_COLOR

K6_NO_COLOR · boolean

Disable colored output.

K6_NO_COLOR=true k6 run script.js

K6_QUIET

K6_QUIET · boolean

Disable progress updates.

K6_QUIET=true k6 run script.js

K6_VERBOSE

K6_VERBOSE · boolean

Enable verbose logging.

K6_VERBOSE=true k6 run script.js

Script Environment Variables

Variables prefixed with K6_ are k6 configuration. To pass custom variables to your script:

# Set custom variables (not K6_ prefixed)
API_URL=https://api.example.com k6 run --include-system-env-vars script.js

# Or use -e flag
k6 run -e API_URL=https://api.example.com script.js

In your script:

export default function() {
  const apiUrl = __ENV.API_URL;
  console.log(apiUrl);
}

CI/CD Best Practices

Secrets Management

Never hardcode secrets in scripts:

# Good - use environment variables
K6_CLOUD_TOKEN=$SECRET_TOKEN k6 cloud run script.js

# Bad - token in script
export const options = {
  cloud: { token: 'hardcoded-token' }
};

Configuration Matrix

Use environment variables for test variants:

# Smoke test
VU_COUNT=1 DURATION=1m k6 run script.js

# Load test
VU_COUNT=100 DURATION=10m k6 run script.js

# Stress test
VU_COUNT=500 DURATION=30m k6 run script.js

Output Configuration

Configure outputs per environment:

# Development
K6_OUT=json=dev-results.json k6 run script.js

# Production
K6_OUT="influxdb=http://influxdb:8086,cloud" k6 run script.js

Boolean Values

Environment variables accept these boolean values:

True: 1, t, T, true, TRUE, True False: 0, f, F, false, FALSE, False

Example:

K6_NO_COLOR=1 k6 run script.js        # true
K6_NO_COLOR=true k6 run script.js     # true
K6_NO_COLOR=false k6 run script.js    # false

See Also

• CLI Options Reference
• Configuration File Format
• k6 run