There is no direct shuttle from EWR to JFK, according to Trip Advisor. People can travel from EWR to JFK via public transportation, express bus service, cab and car.
Public transportation to JFK from EWR is tedious and requires taking four trains with three transfers. This includes the Airtrain to the New Jersey Transit station, transferring to the New Jersey Transit train and taking it to Penn Station NYC. From there, travelers take the Long Island Railroad to the Jamaica Airtrain station and transfer to the Airtrain, which goes on to JFK.
Express bus service, taxi service and car service are also available. As of 2015, cab fare for the trip is around $85 plus tolls.