If you’re wondering why many of the Internet’s most popular websites and services were down for a couple hours today, look no further than the widespread outages experienced by Amazon’s popular web hosting and storage platform.

The outages are due to “high error rates with S3 in US-EAST-1,” according to Amazon’s AWS service health dashboard. The company has been working on fixing the issue since the early afternoon, and as of 4:12 PM (EST), announced that “S3 object retrieval, listing and deletion are fully recovered now,” but that it is still working to “recover normal operations for adding new objects to S3.”

S3 is used by around 148,213 websites and 121,761 unique domains – approximately 0.8 per cent of the top one million websites – according to data from SimilarTech. It offers hosting for images on websites, entire websites themselves, as well as app backends, including Nest, a home automation platform.

Affected websites and services include project management tool Trello; team chat platform Slack; news website Business Insider; online publishing platform Medium; community question-and-answer site Quora; newsletter provider Sailthru; and image hoster Giphy. Also affected were Internet of Things hardware such as connected lightbulbs and thermostats.

Ironically, Isitdownrightnow.com also appears to have suffered from the outage.