Many popular websites briefly became unreachable to internet users on Thursday in a widespread global outage of service.
Visitors attempting to reach many sites received DNS errors, meaning their computer or phone could not connect to the websites.
At first many worried that the World Wide Web was under cyber attack from unknown hackers.
The disruption lasted up to an hour and was actually caused by a bug in the domain name system (DNS) service, which turns the word-based web addresses we use into numerical addresses that point to the required computer server somewhere online.
DNS provider, Akamai Technologies Inc said the outage was triggered during one of its software updates.
“We have implemented a fix for this issue, and based on current observations, the service is resuming normal operations,” Akamai said in a tweet. “We are reviewing our software update process to prevent future disruptions.”
Internet outage monitoring platform DownDetector had reported millions of problems across dozens of platforms.
As some websites began to appear again for users in Europe and the US, others in Asian nations continued to report problems.
This was the second such widespread outage in two months. In June, cloud computing provider Fastly had a hiccup which took down a large number of high-profile websites around the world, including many international newspapers and government websites.
In that case, it later emerged that a settings change by one customer had inadvertently affected the entire infrastructure.