A major outage has affected a number of high profile websites including Amazon, Reddit and Twitch.
The UK government website – gov.uk – was also down as were the Financial Times, the Guardian and the New York Times.
Cloud computing provider Fastly, which underpins a lot of major websites, said it was behind the problems.
In a statement, it said: “We identified a service configuration that triggered disruption across our POPs (points of presence) globally and have disabled that configuration.
A POP allows content to be sent from globally distributed servers that are close to the end-use.
“Our global network is coming back online.”
The issues began at around 11am BST and lasted for an hour.
In an update, they said “The issue has been identified and a fix is being implemented. Jun 8, 10:44 UTC What’s possible now is a bunch of sites will suffer from a second outage due to lack of caching as their application servers have to suddenly catch up.”
Other affected heavy traffic websites included CNN and streaming sites Twitch and Hulu.
The outage also broke some parts of other services, including Twitter’s emojis.