API Parameters

This page provides an overview of all available parameters for both the HTML/CSS API and Screenshot API. Click on any parameter to see detailed examples and usage information.

HTML/CSS API Parameters

Required Parameters

Parameter	Type	Description
html	string	The HTML content to render. Can include inline CSS and JavaScript.

Optional Parameters

Parameter	Type	Default	Description
css	string	null	Additional CSS to inject into the page. Useful for keeping styles separate from HTML.
width	integer	1440	Viewport width in pixels. Must be between 1 and 5000.
height	integer	900	Viewport height in pixels. Must be between 1 and 5000.
fullpage	boolean	false	When true, captures the full page height regardless of viewport height.
dpi	integer	2	Device pixel ratio for the capture, between 1 and 4. Higher values increase resolution but also processing time.
webhook_url	string	null	URL to receive a JSON callback with the image URL when the render finishes. Recommended for larger images or higher DPI values.
ms_delay	integer	null	Adds a delay (in milliseconds) before capturing the image, between 1 and 5000. Useful for animations and dynamic content.
wait_for_selector	string	null	Waits for a specific CSS selector to be present before capturing. Note: does not work with iframe content.
format	string	png	Output format: png for an image or pdf for an A4 document with selectable text.
scale_to_fit	boolean	false	PDF only. Scales content wider than the A4 page to fit the page width and trims trailing blank pages.

Screenshot API Parameters

Required Parameters

Parameter	Type	Description
url	string	The URL to capture. Must be a valid, publicly accessible URL.

Optional Parameters

Parameter	Type	Default	Description
css	string	null	Additional CSS to inject into the page. Useful for modifying the page appearance.
width	integer	1440	Viewport width in pixels. Must be between 1 and 5000.
height	integer	900	Viewport height in pixels. Must be between 1 and 5000.
fullpage	boolean	false	When true, captures the full page height regardless of viewport height.
selector	string	null	CSS selector to capture a specific element instead of the full page. Maximum 255 characters.
dpi	integer	1	Device pixel ratio for the capture, between 1 and 4. Higher values increase resolution but also processing time.
webhook_url	string	null	URL to receive a JSON callback with the image URL when the render finishes. Recommended for screenshots.
ms_delay	integer	null	Adds a delay (in milliseconds) before capturing the image, between 1 and 5000. Useful for animations and dynamic content.
wait_for_selector	string	null	Waits for a specific CSS selector to be present before capturing. Note: does not work with iframe content.
format	string	png	Output format: png for an image or pdf for an A4 document with selectable text.
scale_to_fit	boolean	false	PDF only. Scales content wider than the A4 page to fit the page width and trims trailing blank pages.

The Templates API also accepts format and scale_to_fit alongside each template’s own inputs.

Validation errors

An invalid parameter returns HTTP 400 with a validation_error envelope naming the field and the rule that failed (the Templates API returns 422 instead):

{
    "error": "Validation failed",
    "code": "validation_error",
    "details": {
        "width": ["The width field must not be greater than 5000."]
    }
}