I\'m using word-break: break-all; and want to know how I can have the browser automatically insert the hyphens, as demonstrated in an MDN example.
The word-break property and hyphenation are two completely different things. The first one, originally intended for East Asian languages mainly, does bad things to languages like English: it arbitr arily cuts w ords at some poi nts without ind icating that a word has been broke n.
So you should decide whether you have an expression where a line break can be inserted by a browser at any point or whether you want hyphenation.
For hyphenation, the CSS code as such is OK, though many people would advice putting the standard property setting For automatic hyphenation on IE 9, you would need to use either server-side programmed hyphenation or, simpler, client-side hyphenation with tools like Hyphenator.js.hyphens: auto last, after prefixed properties. But it requires that the language of the text be declared in HTML markup, using e.g.