I have noticed a lot of people are still using http://fpltoif.com/ and are facing problems with it. Just wanted to covey this message out again that this website has come to an end. The developer has published this following post regarding its end.
End of Life - FPLtoIF
A few websites I would recommend are:
I personally use IFPlanner and adjust the given FPL by adding Departure, Arrival, and Approach from the airport procedures in the app.