Messaging app WhatsApp was starting to come back online at 0900 GMT and the company said the issue has been fixed after users across the world reported problems earlier on Tuesday.
At around 0750 GMT, outage reporting site Downdetector had shown over 68,000 users had reported problems with the app in the United Kingdom. Problems were reported by 19,000 people in Singapore and 15,000 people in South Africa, as well.
"We know people had trouble sending messages on WhatsApp today. We have fixed the issue and apologise for any inconvenience," a spokesperson for WhatsApp parent company Meta Platforms said.
"The brief outage was a result of a technical error on our part and has now been resolved," Meta added.
WhatsApp has become a critical means of communication for households and businesses. When WhatsApp had an hours-long outage last October, it hit trading of assets from cryptocurrencies to oil, before traders switched to alternative platforms such as Telegram.
"This highlights the significance of vast hosting companies directing data around the internet along with companies and individuals relying on single points of communication," said Jack Moore, advisor at Slovakia-based cybersecurity firm ESET.
"Multiple areas will inevitably be significantly impacted as a result of this downtime, along with a predicted financial hit but lessons from other recent prominent times when the internet has gone down will have hopefully taught many to have access to other forms of communication."
WhatsApp's latest outage came during the festive season in India - its biggest market by user count - when people use the platform even more than usual to send season's greetings.
Shares of WhatsApp-parent Meta Platforms rose nearly 4% in afternoon trading. They had fallen 0.7% to $128.85 in premarket trading following the outage.
The company had not sent any fresh updates as users in Asia, India and the United Kingdom started seeing some connections come back online.
#whatsappdown was trending on Twitter, with more than 142000 tweets and hundreds of memes flooding the internet.
"Everyone who noticed #whatsapp is down have come to twitter to confirm it," says one Twitter user.
In the past, rival apps like Telegram, Snap or even Meta's Instagram have seen temporary spikes in users when WhatsApp has been down.
While WhatsApp boasts of over two billion monthly active users and have become a mainstay for messaging in most countries, Telegram has taken up the challenger role with about 700 million users.
(Reporting by Nivedita Bhattacharjee in Bengaluru and Supantha Mukherjee in STOCKHOLM; additional reporting by Nandan Mandayam and Tiyashi Datta; Editing by Kirsten Donovan, Mark Potter and Matt Scuffham)
