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browser

The browser module APIs aim for rough compatibility with the Playwright API for NodeJS.

Note that because k6 does not run in NodeJS, the browser module APIs will slightly differ from their Playwright counterparts.

You can find examples of using the browser module API in our getting started guide.

Note

To work with the browser module, make sure you are using the latest k6 version.

Properties

The table below lists the properties you can import from the browser module ('k6/browser').

PropertyDescription
browserThe browser module API is the entry point for all your tests. See the example and the API below.
devicesReturns predefined emulation settings for many end-user devices that can be used to simulate browser behavior on a mobile device. See the devices example below.

Browser Module API

The browser module is the entry point for all your tests, and it is what interacts with the actual web browser via Chrome DevTools Protocol (CDP). It manages:

  • BrowserContext which is where you can set a variety of attributes to control the behavior of pages;
  • and Page which is where your rendered site is displayed.
MethodDescription
browser.closeContext()Closes the current BrowserContext.
browser.context()Returns the current BrowserContext.
browser.isConnected Indicates whether the CDP connection to the browser process is active or not.
browser.newContext([options]) Creates and returns a new BrowserContext.
browser.newPage([options]) Creates a new Page in a new BrowserContext and returns the page. Pages that have been opened ought to be closed using Page.close. Pages left open could potentially distort the results of Web Vital metrics.
browser.version()Returns the browser application’s version.

Example

JavaScript 
import { browser } from 'k6/browser';

export const options = {
  scenarios: {
    browser: {
      executor: 'shared-iterations',
      options: {
        browser: {
          type: 'chromium',
        },
      },
    },
  },
  thresholds: {
    checks: ['rate==1.0'],
  },
};

export default async function () {
  const page = await browser.newPage();

  try {
    await page.goto('https://test.k6.io/');
  } finally {
    await page.close();
  }
}

Then, you can run the test with this command. Also, see the browser module options for customizing the browser module’s behavior using environment variables.

bash 
$ k6 run script.js
docker 
# WARNING!
# The grafana/k6:master-with-browser image launches a Chrome browser by setting the
# 'no-sandbox' argument. Only use it with trustworthy websites.
#
# As an alternative, you can use a Docker SECCOMP profile instead, and overwrite the
# Chrome arguments to not use 'no-sandbox' such as:
# docker container run --rm -i -e K6_BROWSER_ARGS='' --security-opt seccomp=$(pwd)/chrome.json grafana/k6:master-with-browser run - <script.js
#
# You can find an example of a hardened SECCOMP profile in:
# https://raw.githubusercontent.com/jfrazelle/dotfiles/master/etc/docker/seccomp/chrome.json.
docker run --rm -i grafana/k6:master-with-browser run - <script.js
windows 
C:\k6> k6 run script.js
windows-powershell 
PS C:\k6> k6 run script.js

Devices example

To emulate the browser behaviour on a mobile device and approximately measure the browser performance, you can import devices from k6/browser.

JavaScript 
import { browser, devices } from 'k6/browser';

export const options = {
  scenarios: {
    browser: {
      executor: 'shared-iterations',
      options: {
        browser: {
          type: 'chromium',
        },
      },
    },
  },
  thresholds: {
    checks: ['rate==1.0'],
  },
};

export default async function () {
  const iphoneX = devices['iPhone X'];
  const context = await browser.newContext(iphoneX);
  const page = await context.newPage();

  try {
    await page.goto('https://test.k6.io/');
  } finally {
    page.close();
  }
}

Browser-level APIs

k6 ClassDescription
BrowserContext Enables independent browser sessions with separate Pages, cache, and cookies.
ElementHandle Represents an in-page DOM element.
Frame Access and interact with the Page.’s Frames.
JSHandleRepresents an in-page JavaScript object.
KeyboardUsed to simulate the keyboard interactions with the associated Page.
LocatorThe Locator API makes it easier to work with dynamically changing elements.
MouseUsed to simulate the mouse interactions with the associated Page.
Page Provides methods to interact with a single tab in a browser.
Request Used to keep track of the request the Page makes.
Response Represents the response received by the Page.
TouchscreenUsed to simulate touch interactions with the associated Page.
WorkerRepresents a WebWorker.

Browser module options

You can customize the behavior of the browser module by providing browser options as environment variables.

Environment VariableDescription
K6_BROWSER_ARGSExtra 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 command example below).
K6_BROWSER_DEBUGAll CDP messages and internal fine grained logs will be logged if set to true.
K6_BROWSER_EXECUTABLE_PATHOverride search for browser executable in favor of specified absolute path.
K6_BROWSER_HEADLESSShow browser GUI or not. true by default.
K6_BROWSER_IGNORE_DEFAULT_ARGSIgnore any of the default arguments included when launching a browser process.
K6_BROWSER_TIMEOUTDefault timeout for initializing the connection to the browser instance. '30s' if not set.
K6_BROWSER_TRACES_METADATASets additional key-value metadata that is included as attributes in every span generated from browser module traces. Example: K6_BROWSER_TRACES_METADATA=attr1=val1,attr2=val2. This only applies if traces generation is enabled, refer to Traces output for more details.

The following command passes the browser options as environment variables to launch a headful browser with custom arguments.

bash 
$ K6_BROWSER_HEADLESS=false K6_BROWSER_ARGS='show-property-changed-rects' k6 run script.js
docker 
# WARNING!
# The grafana/k6:master-with-browser image launches a Chrome browser by setting the
# 'no-sandbox' argument. Only use it with trustworthy websites.
#
# As an alternative, you can use a Docker SECCOMP profile instead, and overwrite the
# Chrome arguments to not use 'no-sandbox' such as:
# docker container run --rm -i -e K6_BROWSER_ARGS='' --security-opt seccomp=$(pwd)/chrome.json grafana/k6:master-with-browser run - <script.js
#
# You can find an example of a hardened SECCOMP profile in:
# https://raw.githubusercontent.com/jfrazelle/dotfiles/master/etc/docker/seccomp/chrome.json.
docker run --rm -i -e K6_BROWSER_HEADLESS=false -e K6_BROWSER_ARGS='show-property-changed-rects' grafana/k6:master-with-browser run - <script.js
windows 
C:\k6> set "K6_BROWSER_HEADLESS=false" && set "K6_BROWSER_ARGS='show-property-changed-rects' " && k6 run script.js
windows-powershell 
PS C:\k6> $env:K6_BROWSER_HEADLESS="false" ; $env:K6_BROWSER_ARGS='show-property-changed-rects' ; k6 run script.js