August, 7, Hugo, 5, and Goldie Field, 1, died on 15 November in what's being treated as a murder-suicide.
Their father, 36-year-old Dean Field, also died in the fire at the family home. He is suspected of murdering the three children before dying by suicide.
The funeral, held at Crossroads Church in Palmerston North began at 11am.
The children, in brightly coloured coffins, were brought into the funeral home and placed alongside one another.
The family dog Marlo, who also died in the fire, was placed beside them.
'Motorcycle Drive By' by Zach Bryan was played, one of the childrens' favourite songs.
Officiate Aingie Miller began the service saying August, Hugo and Goldie were adored by family and everyone's hearts are full of love and compassion or everyone grieving.
Miller described August, also known as Auggie, as a welcome blessing who was cheeky, mischievous and a natural entertainer with speed as his super power.
Hugo, also known as Johnny, liked a bit of "rough and tumble" wit his older brother but they were also kind and caring with each other. His super power was strength.
"Goldie girl" had the super power of happiness.
Reading on behalf on the children's mother Chelsey Field, Miller started saying "my sweet three beautiful brown-eyes darlings, you are my absolute world".
Field said August James' favourite colour was blue and he loved machinery, cars and motorbikes.
He loved music and Field said she spent six weeks of lockdown listening to him sing 'We Will Rock You' about 50 times a day.
Field said August loved sports, being social and fishing trips with his papa.
August would have been 8 on Thursday.
Hugo John was a snuggly, sensitive mama's boy from birth, Field said.
He had a "huge obsession" with dinosaurs and Field said she had to learn all the names of them to read dinosaur books to him.
He loved he colour green, riding motorbikes, building huts and was constantly trying to keep up with his big brother.
Field said he was unable to say August at first - calling him Cecil instead.
Field said Goldie kept her on her toes her entire pregnancy but was the "sweetest little girl" who loves snuggles and sleepy cuddles.
She was a happy, cruisey baby who was used to being out and about with her big brothers' activities.
She had four teeth, was confidently pulling herself to stand and cruising around the furniture.
Field said she would miss constantly hearing "mum, I'm hungry" and the boys saying "67" constantly.
"I will miss you three so much. You will know your mum will love you forever and ever."
