Can CSS force a line break after each word in an element?

The answer given by @HursVanBloob works only with fixed width parent container, but fails in case of fluid-width containers.

I tried a lot of properties, but nothing worked as expected. Finally I came to a conclusion that giving word-spacing a very huge value works perfectly fine.

p { word-spacing: 9999999px; }

or, for the modern browsers you can use the CSS vw unit (visual width in % of the screen size).

p { word-spacing: 100vw; }

Use

.one-word-per-line {
    word-spacing: <parent-width>; 
}

.your-classname{
    width: min-intrinsic;
    width: -webkit-min-content;
    width: -moz-min-content;
    width: min-content;
    display: table-caption;
    display: -ms-grid;
    -ms-grid-columns: min-content;
}

where <parent-width> is the width of the parent element (or an arbitrary high value that doesn't fit into one line). That way you can be sure that there is even a line-break after a single letter. Works with Chrome/FF/Opera/IE7+ (and probably even IE6 since it's supporting word-spacing as well).

An alternative solution is described on Separate sentence to one word per line, by applying display:table-caption; to the element

Try using white-space: pre-line;. It creates a line-break wherever a line-break appears in the code, but ignores the extra whitespace (tabs and spaces etc.).

First, write your words on separate lines in your code:

<div>Short
Word</div>

Then apply the style to the element containing the words.

div { white-space: pre-line; }

Be careful though, every line break in the code inside the element will create a line break. So writing the following will result in an extra line break before the first word and after the last word:

<div>
    Short
    Word
</div>

There's a great article on CSS Tricks explaining the other white-space attributes.