Determine if menu link is current/active When rendering a menu, in the twig file, you can set a class if item.in_active_trail is set:

  {% for item in items %}
    {%
      set classes = [
        item.in_active_trail ? 'is-active',
      ]
    %}


However this class is applied to each link in the trail - so if you are on the third level, three links get this class.

Is there anything I can see OOTB on item or add to it if the menu link is the current page? I need to highlight it and not just items in the trail itself.
Have you tried to combine it with item.below? I suppose (not tested) that this could be used to only apply the class to the deepest item within the active trail. The code could look something like this:

{% for item in items %}
  {% if item.in_active_trail and not item.below %}
    set classes = [
       'is-active',
    ]
  {% endif %}
{% endfor %}