Users from Scandinavia to Saudi Arabia to South Africa reported outages. India and Russia also suffered performance issues, according to a Twitter technical site.
Both Twitter’s Internet and mobile services began experiencing outages concentrated in northern Europe around 0820 GMT.
Intermittent breakdowns later spread to the United States and Canada in the early part of their working day.
Sporadic disruptions continued at 1420 GMT, six hours after they first began to spread. At approximately 1745 GMT Twitter reported that some users were still having trouble accessing the service.
Fifteen minutes later the company announced the service problems had been resolved. A company spokeswoman had no further comment.
In a status update at 1800 GMT, Twitter said an “intermittent issue affecting some users” was related to “an internal code change.”
“We reverted the change, which fixed the issue,” Twitter said in a statement.
Twitter fell 7 percent at market close. Wall Street has long worried about Twitter’s stagnant growth in users and advertising revenue. The site going tits up so spectacularly added to the worries.
Many pointed out that Twitter could not have been down for everyone since #twitterdown was among the top trending hashtags on the site.
Twitter currently has just over 300 million users but had its slowest user growth in 2015. It was eclipsed by photo-sharing app Instagram, which is owned by Facebook Inc and surpassed 400 million users last year.