Chrome DevTools Protocol

Methods

Emulation.clearDeviceMetricsOverride

Clears the overridden device metrics.

Emulation.clearGeolocationOverride

Clears the overridden Geolocation Position and Error.

Emulation.clearIdleOverride

Clears Idle state overrides.

Emulation.setCPUThrottlingRate

Enables CPU throttling to emulate slow CPUs.

parameters
rate
number

Throttling rate as a slowdown factor (1 is no throttle, 2 is 2x slowdown, etc).

Emulation.setDefaultBackgroundColorOverride

Sets or clears an override of the default background color of the frame. This override is used if the content does not specify one.

parameters
color
DOM.RGBA

RGBA of the default background color. If not specified, any existing override will be cleared.

Emulation.setDeviceMetricsOverride

Overrides the values of device screen dimensions (window.screen.width, window.screen.height, window.innerWidth, window.innerHeight, and "device-width"/"device-height"-related CSS media query results).

parameters
width
integer

Overriding width value in pixels (minimum 0, maximum 10000000). 0 disables the override.

height
integer

Overriding height value in pixels (minimum 0, maximum 10000000). 0 disables the override.

deviceScaleFactor
number

Overriding device scale factor value. 0 disables the override.

mobile
boolean

Whether to emulate mobile device. This includes viewport meta tag, overlay scrollbars, text autosizing and more.

scale
number

Scale to apply to resulting view image.

Experimental
screenWidth
integer

Overriding screen width value in pixels (minimum 0, maximum 10000000).

Experimental
screenHeight
integer

Overriding screen height value in pixels (minimum 0, maximum 10000000).

Experimental
positionX
integer

Overriding view X position on screen in pixels (minimum 0, maximum 10000000).

Experimental
positionY
integer

Overriding view Y position on screen in pixels (minimum 0, maximum 10000000).

Experimental
dontSetVisibleSize
boolean

Do not set visible view size, rely upon explicit setVisibleSize call.

Experimental
screenOrientation
ScreenOrientation

Screen orientation override.

viewport
Page.Viewport

If set, the visible area of the page will be overridden to this viewport. This viewport change is not observed by the page, e.g. viewport-relative elements do not change positions.

Experimental
displayFeature
DisplayFeature

If set, the display feature of a multi-segment screen. If not set, multi-segment support is turned-off.

Experimental
devicePosture
DevicePosture

If set, the posture of a foldable device. If not set the posture is set to continuous. Deprecated, use Emulation.setDevicePostureOverride.

ExperimentalDeprecated

Emulation.setEmulatedMedia

Emulates the given media type or media feature for CSS media queries.

parameters
media
string

Media type to emulate. Empty string disables the override.

features
array[ MediaFeature ]

Media features to emulate.

Emulation.setEmulatedVisionDeficiency

Emulates the given vision deficiency.

parameters
type
string

Vision deficiency to emulate. Order: best-effort emulations come first, followed by any physiologically accurate emulations for medically recognized color vision deficiencies.

Allowed Values: none, blurredVision, reducedContrast, achromatopsia, deuteranopia, protanopia, tritanopia

Emulation.setGeolocationOverride

Overrides the Geolocation Position or Error. Omitting any of the parameters emulates position unavailable.

parameters
latitude
number

Mock latitude

longitude
number

Mock longitude

accuracy
number

Mock accuracy

Emulation.setIdleOverride

Overrides the Idle state.

parameters
isUserActive
boolean

Mock isUserActive

isScreenUnlocked
boolean

Mock isScreenUnlocked

Emulation.setScriptExecutionDisabled

Switches script execution in the page.

parameters
value
boolean

Whether script execution should be disabled in the page.

Emulation.setTimezoneOverride

Overrides default host system timezone with the specified one.

parameters
timezoneId
string

The timezone identifier. List of supported timezones: https://source.chromium.org/chromium/chromium/deps/icu.git/+/faee8bc70570192d82d2978a71e2a615788597d1:source/data/misc/metaZones.txt If empty, disables the override and restores default host system timezone.

Emulation.setTouchEmulationEnabled

Enables touch on platforms which do not support them.

parameters
enabled
boolean

Whether the touch event emulation should be enabled.

maxTouchPoints
integer

Maximum touch points supported. Defaults to one.

Emulation.setUserAgentOverride

Allows overriding user agent with the given string. userAgentMetadata must be set for Client Hint headers to be sent.

parameters
userAgent
string

User agent to use.

acceptLanguage
string

Browser language to emulate.

platform
string

The platform navigator.platform should return.

userAgentMetadata
UserAgentMetadata

To be sent in Sec-CH-UA-* headers and returned in navigator.userAgentData

Experimental

Emulation.canEmulate Deprecated

Tells whether emulation is supported.

Return Object
result
boolean

True if emulation is supported.

Emulation.clearDevicePostureOverride Experimental

Clears a device posture override set with either setDeviceMetricsOverride() or setDevicePostureOverride() and starts using posture information from the platform again. Does nothing if no override is set.

Emulation.getOverriddenSensorInformation Experimental

parameters
type
SensorType
Return Object
requestedSamplingFrequency
number

Emulation.resetPageScaleFactor Experimental

Requests that page scale factor is reset to initial values.

Emulation.setAutoDarkModeOverride Experimental

Automatically render all web contents using a dark theme.

parameters
enabled
boolean

Whether to enable or disable automatic dark mode. If not specified, any existing override will be cleared.

Emulation.setAutomationOverride Experimental

Allows overriding the automation flag.

parameters
enabled
boolean

Whether the override should be enabled.

Emulation.setDevicePostureOverride Experimental

Start reporting the given posture value to the Device Posture API. This override can also be set in setDeviceMetricsOverride().

parameters
posture
DevicePosture

Emulation.setDisabledImageTypes Experimental

parameters
imageTypes
array[ DisabledImageType ]

Image types to disable.

Emulation.setDocumentCookieDisabled Experimental

parameters
disabled
boolean

Whether document.coookie API should be disabled.

Emulation.setEmitTouchEventsForMouse Experimental

parameters
enabled
boolean

Whether touch emulation based on mouse input should be enabled.

configuration
string

Touch/gesture events configuration. Default: current platform.

Allowed Values: mobile, desktop

Emulation.setFocusEmulationEnabled Experimental

Enables or disables simulating a focused and active page.

parameters
enabled
boolean

Whether to enable to disable focus emulation.

Emulation.setHardwareConcurrencyOverride Experimental

parameters
hardwareConcurrency
integer

Hardware concurrency to report

Emulation.setLocaleOverride Experimental

Overrides default host system locale with the specified one.

parameters
locale
string

ICU style C locale (e.g. "en_US"). If not specified or empty, disables the override and restores default host system locale.

Emulation.setPageScaleFactor Experimental

Sets a specified page scale factor.

parameters
pageScaleFactor
number

Page scale factor.

Emulation.setPressureSourceOverrideEnabled Experimental

Overrides a pressure source of a given type, as used by the Compute Pressure API, so that updates to PressureObserver.observe() are provided via setPressureStateOverride instead of being retrieved from platform-provided telemetry data.

parameters
enabled
boolean
source
PressureSource
metadata
PressureMetadata

Emulation.setPressureStateOverride Experimental

Provides a given pressure state that will be processed and eventually be delivered to PressureObserver users. |source| must have been previously overridden by setPressureSourceOverrideEnabled.

parameters
source
PressureSource
state
PressureState

Emulation.setScrollbarsHidden Experimental

parameters
hidden
boolean

Whether scrollbars should be always hidden.

Emulation.setSensorOverrideEnabled Experimental

Overrides a platform sensor of a given type. If |enabled| is true, calls to Sensor.start() will use a virtual sensor as backend rather than fetching data from a real hardware sensor. Otherwise, existing virtual sensor-backend Sensor objects will fire an error event and new calls to Sensor.start() will attempt to use a real sensor instead.

parameters
enabled
boolean
type
SensorType
metadata
SensorMetadata

Emulation.setSensorOverrideReadings Experimental

Updates the sensor readings reported by a sensor type previously overridden by setSensorOverrideEnabled.

parameters
type
SensorType
reading
SensorReading

Emulation.setVirtualTimePolicy Experimental

Turns on virtual time for all frames (replacing real-time with a synthetic time source) and sets the current virtual time policy. Note this supersedes any previous time budget.

parameters
policy
VirtualTimePolicy
budget
number

If set, after this many virtual milliseconds have elapsed virtual time will be paused and a virtualTimeBudgetExpired event is sent.

maxVirtualTimeTaskStarvationCount
integer

If set this specifies the maximum number of tasks that can be run before virtual is forced forwards to prevent deadlock.

initialVirtualTime
Network.TimeSinceEpoch

If set, base::Time::Now will be overridden to initially return this value.

Return Object
virtualTimeTicksBase
number

Absolute timestamp at which virtual time was first enabled (up time in milliseconds).

Emulation.setNavigatorOverrides ExperimentalDeprecated

Overrides value returned by the javascript navigator object.

parameters
platform
string

The platform navigator.platform should return.

Emulation.setVisibleSize ExperimentalDeprecated

Resizes the frame/viewport of the page. Note that this does not affect the frame's container (e.g. browser window). Can be used to produce screenshots of the specified size. Not supported on Android.

parameters
width
integer

Frame width (DIP).

height
integer

Frame height (DIP).

Events

Emulation.virtualTimeBudgetExpired Experimental

Notification sent after the virtual time budget for the current VirtualTimePolicy has run out.

Types

Emulation.DevicePosture

Type: object

properties
type
string

Current posture of the device

Allowed Values: continuous, folded

Emulation.DisplayFeature

Type: object

properties
orientation
string

Orientation of a display feature in relation to screen

Allowed Values: vertical, horizontal
offset
integer

The offset from the screen origin in either the x (for vertical orientation) or y (for horizontal orientation) direction.

maskLength
integer

A display feature may mask content such that it is not physically displayed - this length along with the offset describes this area. A display feature that only splits content will have a 0 mask_length.

Emulation.MediaFeature

Type: object

properties
name
string
value
string

Emulation.ScreenOrientation

Screen orientation.

Type: object

properties
type
string

Orientation type.

Allowed Values: portraitPrimary, portraitSecondary, landscapePrimary, landscapeSecondary
angle
integer

Orientation angle.

Emulation.DisabledImageType Experimental

Enum of image types that can be disabled.

Allowed Values: avif, webp

Type: string

Emulation.PressureMetadata Experimental

Type: object

properties
available
boolean

Emulation.PressureSource Experimental

Allowed Values: cpu

Type: string

Emulation.PressureState Experimental

Allowed Values: nominal, fair, serious, critical

Type: string

Emulation.SensorMetadata Experimental

Type: object

properties
available
boolean
minimumFrequency
number
maximumFrequency
number

Emulation.SensorReading Experimental

Type: object

properties
single
SensorReadingSingle
xyz
SensorReadingXYZ
quaternion
SensorReadingQuaternion

Emulation.SensorReadingQuaternion Experimental

Type: object

properties
x
number
y
number
z
number
w
number

Emulation.SensorReadingSingle Experimental

Type: object

properties
value
number

Emulation.SensorReadingXYZ Experimental

Type: object

properties
x
number
y
number
z
number

Emulation.SensorType Experimental

Used to specify sensor types to emulate. See https://w3c.github.io/sensors/#automation for more information.

Allowed Values: absolute-orientation, accelerometer, ambient-light, gravity, gyroscope, linear-acceleration, magnetometer, relative-orientation

Type: string

Emulation.UserAgentBrandVersion Experimental

Used to specify User Agent Client Hints to emulate. See https://wicg.github.io/ua-client-hints

Type: object

properties
brand
string
version
string

Emulation.UserAgentMetadata Experimental

Used to specify User Agent Client Hints to emulate. See https://wicg.github.io/ua-client-hints Missing optional values will be filled in by the target with what it would normally use.

Type: object

properties
brands
array[ UserAgentBrandVersion ]

Brands appearing in Sec-CH-UA.

fullVersionList
array[ UserAgentBrandVersion ]

Brands appearing in Sec-CH-UA-Full-Version-List.

fullVersion
string
Deprecated
platform
string
platformVersion
string
architecture
string
model
string
mobile
boolean
bitness
string
wow64
boolean

Emulation.VirtualTimePolicy Experimental

advance: If the scheduler runs out of immediate work, the virtual time base may fast forward to allow the next delayed task (if any) to run; pause: The virtual time base may not advance; pauseIfNetworkFetchesPending: The virtual time base may not advance if there are any pending resource fetches.

Allowed Values: advance, pause, pauseIfNetworkFetchesPending

Type: string