Browser Options and Emulation

Mar 04, 2024
3 minutes to read

Browser Command Line Flags

You can specify browser launch options in the Run Configuration Dialog. Expand Browser Options and specify the flags in the CLI flags field.

Note

For a list of browser options, refer to the following resources:

Chromium Command Line Switches for Google Chrome, Chromium, and the new Microsoft Edge.
IE Command-Line Options

Note that Safari does not support command line flags.

Device Emulation

Chromium and Chromium-based browsers (Google Chrome, Microsoft Edge) include a device emulator.

To enable the emulator, open the Run Configuration Dialog, expand the Browser Options tab, and specify emulation settings.

Join the name of the parameter and its value with the equals sign (=). Separate parameters with semicolons (;) - do not use spaces.

Emulate a Device

Specify the target device with the device parameter.

Note

See the full list of supported devices in DevTools -> ⋮ -> Settings -> Devices

Emulate Screen Size

You can specify parameters such as width, height, or orientation to configure the emulator.

Custom User Agent

Use the userAgent parameter to specify a custom user agent string.

Warning

Invalid or incompatible user agent strings may lead to test errors. Escape semicolons (;) with double backslashes.

Emulation Parameters

Use the following parameters to configure the Chromium device emulator. Specify them after the emulation parameter as in the examples above.

Parameter	Type	Description	Default
`device` (optional)	String	The name of the device (see the full list of supported devices in DevTools -> ⋮ -> Settings -> Devices).	No default value.
`width` (optional)	Number	The device screen width in pixels.	The width of the device. If the `device` parameter is not set, the default browser width is used.
`height` (optional)	Number	The device’s screen height in pixels.	The height of the selected device. If the `device` parameter is not set, the default browser height is used.
`scaleFactor` (optional)	Number	Device scale factor value.	Depends on the selected `device` or your system parameters.
`mobile` (optional)	Boolean	Defines whether to emulate a mobile device. This includes the viewport meta tag, overlay scrollbars, text autosizing, etc.	`true` if a mobile device is set using the `device` property. Otherwise, `false`.
`orientation` (optional)	`vertical`	`horizontal`	The device orientation
`userAgent` (optional)	String	The user agent string	The user agent string of the selected `device` or the browser.
`touch` (optional)	Boolean	Enables or disables touch event emulation.	`true` if a touch-supported device is set via the `device` property or your system supports touch events. Otherwise, `false`.
`cdpPort` (optional)	Number	A port (0-65535) used for Chrome DevTools Protocol.	`9222` if you enable Load user profile. Otherwise, TestCafe automatically assigns a free port.

User Profiles

TestCafe Studio starts browsers with an empty profile to ensure consistent test results on different machines. However, you can run tests with the current user profile in Chromium browsers and Firefox.

To do this, enable the Load user profile setting in the Browser Options section of the Run Configuration dialog.

Note

You cannot load the current user profile in headless mode.