Testing tip: Always show scrollbars
Many designers and engineers have Apple products with their flawless and praise-worthy trackpads. By default on macOS, trackpad means only “shy” (iPhone-like) scrollbars are shown. Shy scrollbars become half-visible when two-finger scrolling, and only fully visible when hovering over them.

To anyone working on front-end, I encourage you to toggle this setting to “Always,” and convince half of your team to do the same. Your macOS will now pretend you have a mouse connected, and show more traditional scrollbars, all the time.

Why? Because you might already be accidentally generating spurious scrollbars without realizing. Here’s something I just spotted in Coda today:
This scrollbar serves no purpose, so it will become visual noise for a lot of your users. But when you yourself use “shy” scrollbars, you might not even realize.
Of course, the scrollbar is just a symptom of a bigger problem – an accidentally scrolling surface that will be janky to everyone regardless of their scrollbar visibility status.
Always-visible scrollbars make it easier to spot these, not to mention also being helpful in spotting:
- scrollbars mismatched in theme (e.g. light scrollbars on dark-theme surfaces) or accidentally left unstyled
- scrollbars not fully nestled into their correct edge, accidentally being offset from the top or the right
- accidentally using a wrong CSS setting for overflow (or not knowing about the -x and -y variants), and showing both scrollbars when one will suffice
- the loading state or skeletons not anticipating a scrollbar appearing later
- that most frustrating occasional math/measurement issue where the appearance of vertical scrollbar reduces the horizontal space, and as a result also makes a horizontal scrollbar appear (see also: scrollbar-gutter)