This is the GRONI (General Records Office of Northern Ireland) website for birth, marriage, death, and WWII registrations; birth, marriage, death, civil partnership, and adoption certificates; townland maps, and free name searches of their databases.
For the free searches: “You do not need to register or log in to use the free name search. If you use the free name search it will return the number of matches in each registration type. You may search a five year range e.g. 1868 to 1872.”