A major outage has affected a number of high profile websites including Amazon, Reddit and Twitch.
Other sites such as the Financial Times, the Guardian, the New York Times and the UK government website were also affected.
Cloud computing provider Fastly, which underpins a lot of major websites, said it was behind the problems.
It said there were issues with its global content delivery network (CDN) and was implementing a fix.
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 started around 11am BST and lasted for an hour. Other affected websites included CNN and streaming sites Twitch and Hulu. The outage also broke some parts of other services, including Twitter’s emojis.
Websites were also beginning to be restored, after an hour of downtime.
