What is the plural form of "whitespace"?

I ask this because Firefox suggested that whitespaces is not a valid word; rather it gave me whitespace or white spaces.

Solution 1:

The word "whitespace" is usually uncountable. If you need it to be countable, I would suggest saying "whitespace characters".

Solution 2:

The design sense of "white space" is normally given as two words. Like Neil says, it's an uncountable noun. Like water, time, and money, you can have a lot of it, or you might need more. (When it comes to white space, people usually need more.)

Solution 3:

The term "whitespace" (without a space between "white" and "space") is, I think, borrowed from computing, in which characters that produce no on-screen glyphs, but only serve to separate groups of visible characters, are referred to collectively as "whitespace characters" (e.g. space, tab, new line). Since whitespace can refer to any one, or sequence, of such characters, you cannot really say that whitespace necessarily means a collection of space characters, because it might be a tab, followed by two spaces, followed by another tab, followed by a carriage return, etc.. In most programming languages, the formatting of program text is only for human legibility, and the computer couldn't really care less about whether two commands are placed on the same line or two separate lines, as long as there is SOME whitespace to indicate where one command ends and the next begins. But because the need to discard these redundant characters comes up so often in computing, they have acquired their own technical term: "whitespace."