WhatsApp users around the world were left without the messaging service for 45 minutes earlier.
People just had a spinning buffer wheel when trying to connect.
No reason's been given but it's understood Facebook - which owns the app - is investigating. It's used by more than 1 billion people globally.
Thousands of people have taken to Twitter to express their panic.
How you feel when WhatsApp is down pic.twitter.com/V4nlwjHGRN
— Jean-Michel Wickli (@halfnhalfmusic) November 3, 2017
Live pictures of WhatsApp this morning pic.twitter.com/bB5A2qttgD
— Cloud9 Insight (@Cloud9Insight) November 3, 2017
When your crush finally starts chatting with you and then Whatsapp goes down. pic.twitter.com/YHii2teFJJ
— KYAMA™ (@Elijahkyama) November 3, 2017
Whatsapp down pic.twitter.com/2DJIMqGElF
— Loli (@asdloli) November 3, 2017
