Card header

The CardHeader widget represents the header of a card. Headers can include a title, subtitle, and avatar-style image.

You can include headers for card messages and dialogs.

The following is a card consisting of CardHeader, image, and subtitle components:

JSON representation and fields

JSON representation
  "title": string,
  "subtitle": string,
  "imageType": enum (ImageType),
  "imageUrl": string,
  "imageAltText": string


Required. The title of the card header. The header has a fixed height: if both a title and subtitle are specified, each takes up one line. If only the title is specified, it takes up both lines.



The subtitle of the card header. If specified, appears on its own line below the title.


enum (ImageType)

The shape used to crop the image.



The HTTPS URL of the image in the card header.



The alternative text of this image that's used for accessibility.


The shape used to crop the image.

SQUARE Default value. Applies a square mask to the image. For example, a 4x3 image becomes 3x3.
CIRCLE Applies a circular mask to the image. For example, a 4x3 image becomes a circle with a diameter of 3.


When a Google Chat app or card returns an error, the Chat interface surfaces a message saying "Something went wrong." or "Unable to process your request." Sometimes the Chat UI doesn't display any error message, but the Chat app or card produces an unexpected result; for example, a card message might not appear.

Although an error message might not display in the Chat UI, descriptive error messages and log data are available to help you fix errors when error logging for Chat apps is turned on. For help viewing, debugging, and fixing errors, see Troubleshoot and fix Google Chat errors.