Configuration

Go to Structure > Menus > Available attributes (/admin/config/menu_link_attributes/config). The page needs the Administer menu link attributes permission.

Without YAML Editor the configuration is a plain textarea, and the page shows a warning recommending the module:

With YAML Editor enabled the textarea becomes a code editor with line numbers, syntax highlighting, and indentation help:

Attributes are defined in YAML under the attributes key. Each key is the HTML attribute name, optionally with the container_ prefix (see Container attributes). Every setting below it is optional.

attributes:
  class:
    label: 'Link class(es)'
    description: 'CSS class for the link. Separate multiple classes by space.'
  target:
    label: 'Link target'
    options:
      _blank: 'New window (_blank)'
      _self: 'Same window (_self)'
    default_value: ''
  rel: {}
  data-tracking-id:
    label: 'Tracking ID'
  container_class:
    label: 'Container class(es)'

Attribute settings

Key	Type	Description
label	string	Field label. Defaults to the attribute name without the container_ prefix, with the first letter uppercased and hyphens replaced by spaces: container_class becomes "Class".
description	string	Help text below the field. Defaults to "Enter value for <name> attribute.", with the name without the container_ prefix.
type	string	Form element type. Defaults to select when options is set, textfield otherwise. See Field types.
options	map	Allowed values, value: 'Label'. Used by select, radios, and checkboxes.
default_value	string	Pre-filled value when the link has no value for this attribute yet. For checkboxes, separate several values with spaces.
container	boolean	true puts the attribute on the <li> without the container_ prefix. See Container attributes.
upload_location	string	Upload directory for the managed_file type. See Field types. Not in the config schema yet, see #3365618.

For an attribute with no settings, use an empty map, as in rel: {} above.

Allowed attribute names

Drupal core drops menu link attribute names it does not accept. The form rejects most of those names up front. The container_ prefix is not part of the name for this check, so its underscore is fine. The rest of the name must:

• start with a letter and contain only letters, digits, and hyphens;
• be at most 96 characters;
• not be style;
• not start with on (event handlers such as onclick).

Core also drops names starting with hx or data-hx (htmx attributes). The form accepts these, but core does not render them, see #3590638.

Underscores are not allowed. Use data-menu-color instead of data_menu_color, and container_menu-color instead of container_menu_color. The form suggests the hyphenated name when you enter one with underscores. Existing names with underscores are renamed on update, see Upgrading.

Values on output

Protocols such as javascript: are removed from attribute values. Values of data-*, class, rel, title, alt, property, and datetime are left as they are.

• Recent Drupal core versions filter link attributes (<a>). Older core versions render them as entered.
• The module filters container attributes (<li>) itself, with core's attribute filter when available and an equivalent filter otherwise.