Australian supermodel Miranda Kerr has announced her engagement to Snapchat founder, billionaire Evan Spiegel.

The Victoria's Secret model shared the news by posting an Instagram photo on Wednesday, but she made sure to add a custom Snapchat filter.

"I said yes!!!" she wrote alongside the photo showing her diamond ring fronted by a Snapchat-owned Bitmoji cartoon depiction of a proposal and a "Marry Me!" graphic.

Reports said they met in 2014 and started dating in June last year.

Snapchat chief executive Spiegel, 26, created and co-founded Snapchat, a photo and video messaging app. The American has an estimated net worth of US$2.1 billion (S$2.85 billion), says Forbes magazine.

Kerr was ranked No. 6 on Forbes' ranking of highest-paid models, earning some US$5.5 million last year.

It would be the second marriage for Kerr, 33, and the first for Spiegel.

She was formerly married to Hollywood actor Orlando Bloom, with whom she has a five-year-old son.