Instagram has stopped working, leaving people unable to load posts or stories.
The outage comes amid another major outage at PlayStation Network, meaning that two of the biggest online services in the world have been hit by problems at the same time.
Instead of loading up posts as normal, the app showed an error page reading "couldn't refresh feed" and would do nothing else.
Attempting to load Instagram profiles on the web also brought up a Facebook-branded error message. "Sorry, something went wrong," it read, "we're working on it and we'll get it fixed as soon as we can."
There doesn't seem to be any way to fix or get around the problem, such as shutting the app or trying from a different account. The wide scale of the outage suggests the issue is with Instagram's servers or the underlying infrastructure that allows users to access them, meaning it will require an equally large scale solution.
A vast number of tweets were posted within minutes of the outage, from users joking that they only ever visited the rival social media site to see whether Instagram had broken. Some users also said they had been worried their Instagram profiles had been deleted or they had been kicked off the service, until they realised it had broken for everyone.
The Facebook-owned site has had a tough year of outages. In March, it – along with Facebook and WhatsApp – suffered one of the biggest failures in the history of the internet, when all three services went down at the same time for hours.
Problems were reported across the world, according to the monitoring website Down Detector. They were particularly bad in Europe, the US and Brazil, according to the site's outage map, but that is probably just because most of its users are online in those countries.
The problems appeared to be affecting everybody who tried to use the app or the website. Instagram is accessed by some half a billion people every day, meaning that millions of people can be hit by even the shortest global outage.
Unlike Facebook and many other major services, Instagram doesn't run an official page for checking on its server status. During particularly long outages it may opt to post from its Twitter feed, but it is yet to do so, with its most recent post showing a dog.
While it's unlikely that the PSN and Instagram outages are linked, problems with the infrastructure underlying the internet can sometimes mean that apparently unrelated services go down simultaneously. At the beginning of the month, for instance, a problem at Google meant that services including Snapchat and YouTube went offline at the same time, for the same reason.
Parent company Facebook did see a spike in reports of problems on outage monitoring sites. But the number of complaints was much lower than would be expected if there was a significant problem, and it is likely that people are simply blaming Instagram's parent company for the failures of the app.