early_​hints

Behavior name: Early Hints

Use Early Hints to send an HTTP 103 status code with preliminary HTTP headers at the client request stage, so that a browser can preload critical website resources or preconnect to a specific domain while waiting for the final response.

The 103 response occurs only when the Sec-Fetch-Mode request header’s value is navigate. Since this is a default setting that’s already a part of the behavior’s logic, you don’t need to set any additional match criteria. However, if you add this behavior to a rule where a requestHeader criteria matches a Sec-Fetch-Mode value other than navigate, you get a validation error.

See the Property Manager guide for more caveats, examples, and implementations using EdgeWorkers.

Default behavior

These samples reflect the behavior's default settings. You can use these as is in your configurations or make adjustments based on the behavior's available options.

data "akamai_property_rules_builder" "early_hints" {
  rules_v2025_02_18 {
    name     = "Early Hints"
    comments = "Sends an HTTP 103 status code with preliminary HTTP headers at the client request stage."
    behavior {
      early_hints {
        enabled = false
      }
    }
  }
}

"behaviors": [
  {
    "name": "earlyHints",
    "options": {
      "enabled": false
      }
  }
]

Options