Always show browser scrollbar to prevent page jumping [duplicate]

Answer 1

Try reading this article by Chris Coyer, it explains it pretty well.

From the article:

Assigning overflow-y to scroll does work, and it works in Firefox, Safari, and IE 6, and that makes it the best solution:

html {
    overflow-y: scroll; 
}

Answer 2

html {
    overflow-y: scroll; 
}

It is the best solution.