HTTP headers | Accept-CH

The HTTP Accept-CH header is a response-type header that indicates the client hints that the server can support and should include in further requests.

Syntax:

Accept-CH: client hints

Note: The client hints can be more than one and are to be separated by commas.

Directives: The HTTP Accept-CH header accepts a single directive as mentioned above and described below:

• client hints: This directive contains a set of HTTP request header fields for proactive content negotiation for indicating a list of device and agent specific preferences.

Below examples will illustrate the HTTP Accepts-CH header:

Examples:

• When one client hint is used. In this example, Viewport-Width is the client hint and it indicates the layout viewport width in CSS pixels.

  Accept-CH: Viewport-Width

• When multiple client hints are used. In this example Viewport-Width and Width are the client hints.

  Accept-CH: Viewport-Width, Width

To check the Accept-CH in action go to Inspect Element -> Network check the response header for Accept-CH like below.

Supported Browsers: The browsers are compatible with the HTTP Accept-CH header are listed below:

• Google Chrome
• Opera