Different Browsers Have Different Scroll Bar Widths
Different browsers on different operating systems will have different sized scrollbars. This can mess up the design of a page.
The default scrollbar width can range anywhere from 12px to 17px. Webkit browsers also have the ability for the user to configure scrollbar widths. Webkit browsers, such as Chrome can have custom scrollbars that can have any size scrollbar.
Check out our scrollbar width detector to see what size your current scrollbar width is. You can try this on different browsers and on different operating systems and see that it changes.