In typography, a thin space is a space character that is usually 1⁄5 or 1⁄6 of an em in width. It is used to add a narrow space, such as between nested quotation marks or to separate glyphs that interfere with one another. It is not as narrow as the hair space.
In Unicode, thin space is encoded at U+2009 thin space (HTML
). Unicode's U+202F narrow no-break space (HTML
) is a non-breaking space with a width similar to that of the thin space.
In LaTeX and Plain TeX,
hinspace produces a narrow, non-breaking space. Outside math formulas in LaTeX,
, also produces a narrow, non-breaking space, but inside math formulas it produces a narrow, breakable space.
In some versions of Microsoft Word, the symbol dialog (often available via Insert > Symbol or Insert > Special Characters), has both the thin space and the narrow no-break space available for point-and-click insertion. In Word's Symbol dialog, under font = "(normal text)", they are found in subset = "General Punctuation", Unicode character 2009 and nearby. Other word processing programs have ways of producing a thin space.
Thin spaces are recommended for use as a thousands separator for measures made with SI units.