The three apps – all of which are part of the Facebook company, and share common technology – stopped working on Friday afternoon UK time.
Users saw error alerts when they opened the app and were unable to send or receive messages.
Facebook’s official “platform status” page, which tracks problems for developers, indicated that the platform is “healthy” and that there were no known issues.
Instagram and WhatsApp do not have their own devoted server status pages, though their official Twitter accounts have occasionally posted about major outages.
The company has been hit by a small number of significant outages in recent years. As the three apps have become more closely intertwined, those outages have become larger, since a problem on one of the platforms usually means that all three go down.
In March 2019, it was hit by the biggest technical issue in its recent history, as all of Facebook’s apps went down for more than a day.