View as markdown
Copy for LLM Open in ChatGPT Open in Claude Open in Perplexity

HeadlessExperimental

Experimental

This domain provides experimental commands only supported in headless mode.

Dependencies: Page, Runtime

Commands

HeadlessExperimental.beginFrame

Sends a BeginFrame to the target and returns when the frame was completed. Optionally captures a
screenshot from the resulting frame. Requires that the target was created with enabled
BeginFrameControl. Designed for use with --run-all-compositor-stages-before-draw, see also
https://goo.gle/chrome-headless-rendering for more background.

Parameters
Name Type Description
frameTimeTicks (optional) number Timestamp of this BeginFrame in Renderer TimeTicks (milliseconds of uptime). If not set,
the current time will be used.
interval (optional) number The interval between BeginFrames that is reported to the compositor, in milliseconds.
Defaults to a 60 frames/second interval, i.e. about 16.666 milliseconds.
noDisplayUpdates (optional) boolean Whether updates should not be committed and drawn onto the display. False by default. If
true, only side effects of the BeginFrame will be run, such as layout and animations, but
any visual updates may not be visible on the display or in screenshots.
screenshot (optional) ScreenshotParams If set, a screenshot of the frame will be captured and returned in the response. Otherwise,
no screenshot will be captured. Note that capturing a screenshot can fail, for example,
during renderer initialization. In such a case, no screenshot data will be returned.
Return Object
Name Type Description
hasDamage boolean Whether the BeginFrame resulted in damage and, thus, a new frame was committed to the
display. Reported for diagnostic uses, may be removed in the future.
screenshotData (optional) binary Base64-encoded image data of the screenshot, if one was requested and successfully taken.

HeadlessExperimental.disable

Deprecated

Disables headless events for the target.

HeadlessExperimental.enable

Deprecated

Enables headless events for the target.

Types

ScreenshotParams

(object)

Encoding options for a screenshot.

Properties
Name Type Description
format (optional) string Image compression format (defaults to png).
quality (optional) integer Compression quality from range [0..100] (jpeg and webp only).
optimizeForSpeed (optional) boolean Optimize image encoding for speed, not for resulting size (defaults to false)

Summary