This is a known issue: https://github.com/twbs/bootstrap/issues/13221
At screen widths <360px, the .col-xs-1
columns start to wrap because..
“while the column is set to width: 8.333333%;, the
column is going to be at least 30px wide because of the 15px padding
on either side. Therefore, there’s a mismatch and the browser just
stacks the columns” – @mdo
The problem can be avoided by not using col-xs-1
on very small screens. You should also consider if the screen will realistically be resized less than 360px. In most cases it is not.
Note: In Bootstrap 4, col-xs-1
is now col-1
.