Should we set a minimum height on a scrollbar thumb?

1. How do you measure thumb scrollbar height?
2. What is thumb in scrollbar?
3. How is scroll bar height calculated?

How do you measure thumb scrollbar height?

The thumb (I've heard people call it a scrubber) size should be the size of the viewport (in your example 200px) divided by the size of the content (600px). So, your thumb should take up 1/3rd the available height.

What is thumb in scrollbar?

a box or “thumb” within a scrollbar that allows the user to move to a specific region by dragging the box to the appropriate location within the scrollbar. Also called a “scrollbox” or “elevator”.

How is scroll bar height calculated?

Height of scrollbar = offsetHeight – clientHeight.