Kiwis playing online video game Fortnite saw internet traffic spike 20 per cent higher than usual last week to never-seen-before levels.

Chorus, the NZX-listed firm which owns fixed-line internet networks around New Zealand, said downloads of Fortnite saw traffic spike last Thursday.

"Data use on the Chorus network grows throughout the day and peaks at about 9pm when hordes of people are streaming online video. On Thursday, the peak was about 20 per cent higher than normal and this correlates with Fortnite version five patch being available for download from 8pm that night," Chorus said today.

"The amount of extra data being used on Chorus network at the peak was the equivalent of about 30,000 gamers downloading the Fortnite software patch," the company said.

Fortnite is a multi-player apocalyptic survival video game which pits players against 99 others in a fight for survival on an island.

Chorus network strategy manager Kurt Rodgers said the company had never seen a spike like that before.

The Fortnite phenomenon was a great example of how fibre internet could support the gaming community, he said.

Chorus operates fibre internet lines in 70 per cent of the country and is due to finish installing the ultra-fast broadband network by 2020.