REUTERS/Adnan Abidi
The ban was ordered after WhatsApp, which is owned by Facebook, failed to cooperate in an investigation in the country. Over 100 million people use the service in Brazil making the ban a big deal.
"Thank you to everybody in Brazil for your support in getting WhatsApp back online," said Jan Koum, the founder of WhatsApp, in a post. "This is a victory for the Brazilian people, and we're glad that your voices were heard loud and clear by people who represent them."
Facebook CEO Mark Zuckerberg also took to Facebook to thank "our community for helping resolve this."
Telecommunication companies in Brazil were ordered to cut-off access to the messaging service for 48 hours starting yesterday morning. The ruling was then overturned at midday local time.
Telegram, a rival messaging service, saw over 1.5 million account sign-ups during the outage.
Business Insider has reached out to WhatsApp to ask about the new ruling. We will update the post when we hear back.