Lorde says her raved-about new single No Better is an "old track" that didn't make her album Pure Heroine.

The Kiwi pop star released the surprise single on Friday in a move that mirrored the release of Beyonce's fifth album, which came out unannounced on the same day.

On Twitter, the Royals singer said the song didn't make her album but she wanted to release it anyway.

She promised her 680,000 Twitter followers that all future released would be "new".

hope you're liking NO BETTER! it's an old track that didn't make the album that i wanted to do something wif. all future stuff will be NEW!

Lorde recently received four Grammy nominations, forcing her to pull out of a headlining performance at the Laneway festival which was on the same day.

She's putting on a make-up show two days later at Silo Park, which will be free for Laneway ticket holders.

Today, she'll be doing an 'Ask Me Anything' Q&A session with fans on Reddit from 10am.

- nzherald.co.nz