WhatsApp, the messaging platform, resumed service after a global outage of approximately 20 minutes on Wednesday.
Hundreds of users worldwide reported on social media that they could not send messages or make phone calls through the app for almost an hour.
Meta, which owns WhatsApp, acknowledged the problem and said it was being fixed.
The company, which also owns Facebook and Instagram, did not explain the reason for the outage.
WhatsApp has nearly 2 billion users, making it an important communication tool for businesses and governments worldwide.
