Only versions 1.4 and below. Versions 1.5 and above do not require an X server. Version 1.5 has been available for 5+ years: https://ariya.io/2012/03/pure-headless-phantomjs-no-x11-or-x...
Does not play well with React Fiber either, in my experience. Aaaand isn't the brain behind PhantomJS stepping down or something? To any potential users: just go with Chrome