Remove Extra Spaces

In short Removing extra spaces collapses runs of two or more spaces into one, strips leading and trailing whitespace from each line, and converts tabs to spaces. The classic source is the double space after a full stop, which was correct on a typewriter — where every character occupied the same width and a wider gap was needed to mark a sentence — and has been wrong in proportional type since the 1950s. Every major style guide now specifies one space, and a document written by someone who learned to type before word processors will have hundreds of doubles in it. The other sources are pasting between applications, where indentation arrives as runs of spaces, and manual alignment, where someone spaced text into columns that fall apart the moment the font changes. What this cannot fix is the non-breaking space, which looks identical to a normal one and is a different character entirely — that is what the text cleaner is for, and it is the usual reason a document still shows odd gaps after every ordinary space has been collapsed.