A record amount of pyrotechnics as well as new fireworks effects and colours will light up the harbour city's skyline for 12 minutes and dazzle the more than 1.5 million spectators expected to crowd foreshores and parks.

"I'm sure we'll delight in seeing our beautiful harbour lit up like never before," Sydney Lord Mayor Clover Moore said.

To mark the international year of indigenous languages in 2019, the harbour will host a ceremony celebrating Aboriginal heritage that includes animations projected onto the Sydney Harbour Bridge's pylons.