Facebook Inc's photo-sharing social network Instagram said on Thursday it has fixed a bug that led to a temporary change in the appearance of its feed for a large number of users.
The bug led to a small test being distributed widely, the company said. As part of the test, some users had to tap and swipe their feed horizontally to view new posts, similar to its Stories feature.
The momentary change sparked widespread outrage among users on Twitter, with several comparing it to Snapchat's unpopular redesign.
The move ignited complaints on Twitter where the hashtag #InstagramUpdate became a top trending issue.
Twitter user Jeffree Star lamented "this #instagramupdate almost ruined my morning!!" while journalist Alex Heath of the online service Cheddar remarked that it "seems maybe intended to reduce mindless
vertical scrolling?" Adam Mosseri, who heads Instagram for Facebook, tweeted that the new design was "a test that went to a few orders of magnitude more people than intended."
"Sorry about that," Instagram said a short time later that it had rolled back the redesign to the normal vertical scroll.
"Due to a bug, some users saw a change to the way their feed appears today," said an Instagram message posted on Twitter.
"We quickly fixed the issue and feed is back to normal. We apologize for any confusion."
Some Instagram users remained upset over the glitch.