Watermark

Display a textual watermark over a configurable list of websites for traceability.

The watermark is drawn over every matching page, including when a page is opened in Reader Mode or View Source. By default it shows the signed-in user's email address with a timestamp below it, which makes screenshots of internal sites traceable.

Compatibility

Firefox	Firefox ESR	Firefox Enterprise
Not supportedNo	Not supportedNo	Available since 154

CCK2 Equivalent: N/A
Preferences Affected: N/A

Examples

policies.json

{
  "policies": {
    "Watermark": {
      "Match": [
        "https://intranet.example.com/*",
        "https://*.corp.example.com/*"
      ],
      "Copy": "CONFIDENTIAL",
      "Color": "rgba(200, 0, 0, 0.2)",
      "FontSize": 28,
      "Angle": -45,
      "SecondaryCopy": "%t - %e"
    }
  }
}

JSON schema

Watermark JSON schema

{
  "type": "object",
  "required": [
    "Match"
  ],
  "properties": {
    "Match": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "Copy": {
      "type": "string"
    },
    "Color": {
      "type": "string"
    },
    "FontSize": {
      "type": "number"
    },
    "Angle": {
      "type": "number"
    },
    "Size": {
      "type": "number"
    },
    "SecondaryCopy": {
      "type": "string"
    }
  }
}

Values

• Match: (required) A list of URL match patterns for the pages to watermark. See Match patterns for syntax. Invalid patterns are ignored, and is limited to the first 1000 patterns.
• Copy: The main line of text. %t is replaced with the current timestamp and %e with the signed-in user's email address. Defaults to the email address, or to CONFIDENTIAL when no email address is available.
• SecondaryCopy: A smaller second line below Copy, with the same substitutions. Defaults to %t. Set it to an empty string to omit the second line.
• Color: The text color, as a CSS color value. Defaults to rgba(200, 0, 0, 0.5), which is also used when the value cannot be parsed.
• FontSize: The font size of Copy, in CSS pixels. Defaults to 28 and is capped at 64.
• Angle: The rotation of the text in degrees. Defaults to -45.
• Size: The size of a single watermark tile, in CSS pixels. Defaults to 300 and is clamped between 100 and 2048.

See also

• WebsiteFilter policy to block sites completely rather than apply a watermark to them.