Twitter plunges a day after Facebook rout

Twitter has plunged before the opening bell in the US on weak user numbers, a day after a historic rout of fellow social media giant Facebook.

Shares of Twitter Inc were down 16 per cent early on Friday.

Twitter had 335 million monthly users in the quarter, below the 339 million Wall Street was expecting, and down slightly from 336 million in the first quarter.

That overshadowed an otherwise strong quarterly performance on Friday.

Second-quarter net income hit $US100.1 million ($A135.6 million) after a loss last year.