launch([options])

Launches a new browser process.

Parameter	Type	Default	Description
args	string[]	null	Extra command line arguments to include when launching browser process. See this link for a list of Chromium arguments. Note that arguments should not start with -- (see the example).
debug	boolean	false	All CDP messages and internal fine grained logs will be logged if set to true.
devtools	boolean	false	Open up developer tools in the browser by default.
env	string[]	null	Environment variables to set before launching browser process.
executablePath	string	null	Override search for browser executable in favor of specified absolute path.
headless	boolean	true	Show browser GUI or not.
ignoreDefaultArgs	string[]	null	Ignore any of the default arguments included when launching browser process.
proxy	string	null	Specify to set browser's proxy configuration.
slowMo	string	null	Slow down input actions and navigation by the specified time e.g. '500ms'.
timeout	string	'30s'	Default timeout to use for various actions and navigation.

Default arguments

List of default arguments included when launching the browser process. You can pass one or more of the arguments to the ignoreDefaultArgs field when launching a browser for the ones you want to ignore.

note
The starting '--' have been omitted from the argument names in these lists.

Argument	Value	Description
disable-background-networking	true	Disables several subsystems which run network requests in the background. This is used during network performance testing to avoid measurement noise.
enable-features	NetworkService, NetworkServiceInProcess	Comma-separated list of feature names to enable.
disable-background-timer-throttling	true	Disables task throttling of timer tasks from background pages.
disable-backgrounding-occluded-windows	true	Disables backgrounding renders for occluded windows. Done for tests to avoid nondeterministic behavior.
disable-breakpad	true	Disables the crash reporting.
disable-component-extensions -with-background-pages	true	Disables default component extensions with background pages. Useful for performance tests where these pages may interfere with results.
disable-default-apps	true	Disables the installation of default apps on the first run. This is used during automated testing.
disable-dev-shm-usage	true	The /dev/shm partition is too small in certain VM environments, causing Chrome to fail or crash. This flag provides a work-around for this issue (a temporary directory will always be used to create anonymous shared memory files).
disable-extensions	true	Disables extensions.
disable-features	ImprovedCookieControls, LazyFrameLoading, GlobalMediaControls, DestroyProfileOnBrowserClose, MediaRouter, AcceptCHFrame	Comma-separated list of feature names to disable.
disable-hang-monitor	true	Suppresses hang monitor dialogs in renderer processes. This may allow slow unload handlers on a page to prevent the tab from closing, but the Task Manager can be used to terminate the offending process in this case.
disable-ipc-flooding-protection	true	Disables the IPC flooding protection. It is activated by default. Some javascript functions can be used to flood the browser process with IPC. This protection limits the rate at which they can be used.
disable-popup-blocking	true	Disables pop-up blocking.
disable-prompt-on-repost	true	Usually, when the user attempts to navigate to a page that was the result of a post request, the browser prompts to make sure that's the intention of the user. This switch may be used to disable that check during automated testing.
disable-renderer-backgrounding	true	Prevents renderer process backgrounding when set.
force-color-profile	srgb	Forces all monitors to be treated as though they have the specified color profile. Accepted values are "srgb" and "generic-rgb" (currently used by Mac layout tests) and "color-spin-gamma24" (used by layout tests).
metrics-recording-only	true	Enables the recording of metrics reports but disables reporting. This executes all the code that a normal client would use for reporting, except the report is dropped rather than sent to the server. This is useful for finding issues in the metrics code during UI and performance tests.
no-first-run	true	Skips the "First Run" tasks, whether or not it's the first run, and the "What's New" page. This does not drop the "First Run" sentinel and thus doesn't prevent "First Run" from occurring the next time Chromium is launched without this flag. It also does not update the last "What's New" milestone, so it does not prevent "What's New" from occurring the next time Chromium is launched without this flag.
enable-automation	true	Enables indication that the browser is controlled by automation.
password-store	basic	Specifies which encryption storage backend to use. The possible values are kwallet, kwallet5, gnome, gnome-keyring, gnome-libsecret, and basic. Any other value will lead to Chromium detecting the best backend automatically.
use-mock-keychain	true	Uses mock keychain on Mac to prevent the blocking permissions dialog about: "Chrome wants to use your confidential information stored in your keychain."
no-service-autorun	true	Disables the service process from adding itself as an autorun process. This does not delete existing autorun registrations, it just prevents the service from registering a new one.
no-startup-window	true	Does not automatically open a browser window on startup (used when launching Chrome for the purpose of hosting background apps).
no-default-browser-check	true	Disables the default browser check. Useful for UI/browser tests where we want to avoid having the default browser info-bar displayed.
headless	true/false	Run in headless mode, i.e., without a UI or display server dependencies. Set by launch options (default true).
auto-open-devtools-for-tabs	true/false	This flag makes Chrome auto-open the DevTools window for each tab. It is intended to be used by developers and automation, not to require user interaction for opening DevTools. Set by launch options (default false).
window-size	800,600	Sets the initial window size. Provided as string in the format "800,600".

Additionally if headless mode is set to true in launch options, the following arguments are also set:

Argument	Value	Description
hide-scrollbars	true	Prevents creating scrollbars for web content. Useful for taking consistent screenshots.
mute-audio	true	Mutes audio sent to the audio device so it is not audible during automated testing.
blink-settings	primaryHoverType=2,availableHoverTypes=2, primaryPointerType=4,availablePointerTypes=4	Sets blink settings. Format is <name>[=<value>],<name>[=<value>],... The names are declared in settings.json5 from chromium project. For boolean type, use "true", "false", or omit '=<value>' part to set to true. For enum type, use the int value of the enum value.

Returns

Type	Description
object	Browser object

Example

import { chromium } from 'k6/experimental/browser';

export default async function () {
  const browser = chromium.launch({
    args: ['show-property-changed-rects'],
    debug: true,
    devtools: true,
    executablePath: '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome',
    headless: false,
    slowMo: '500ms',
    timeout: '30s',
  });
  const context = browser.newContext();
  const page = context.newPage();

  try {
    await page.goto('http://whatsmyuseragent.org/');
    page.screenshot({ path: `example-chromium.png` });
  } finally {
    page.close();
    browser.close();
  }
}

Init context

k6

k6/crypto

k6/data

k6/encoding

k6/execution

k6/experimental

k6/html

k6/http

k6/metrics

k6/net/grpc

k6/ws

Error Codes

launch([options])

Default arguments

Returns

Example

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