WhatsApp outage affected people in different parts of the world, including the UK, and other parts of Europe.
Services of Meta-owned social messaging app WhatsApp were restored after over an hour of outage.
With thousands of users complaining they were unable to send or receive messages in text or video format.
According to Downdetector, a platform that tracks websites, more than 27,000 users reported WhatsApp outage.
69% of the faced problems with sending messages, 24% has troubles with server connection and 7% had issues with the overall app.
"We're aware that some people are currently having trouble sending messages & we're working to restore WhatsApp for everyone as quickly as possible."
Amid outage, social media users said they were unable to connect to the app or send any messages.
The hashtag #whatsappdown was among the most trending on Twitter across the world on Tuesday.
Messaging app "Signal” saw a 138.09% jump in searches since 8 am, while privacy-focused messenger Threema exploded with a 400% jump in searches since the WhatsApp outage, it said.