In computer-based text processing and digital typesetting, a non-breaking space, no-break space or non-breakable space (NBSP) is a variant of the space character that prevents an automatic line break (line wrap) at its position. In certain formats (such as HTML), it also prevents the collapsing of multiple consecutive whitespace characters into a single space. The non-breaking space is also known as a hard space or fixed space. In Unicode, it is encoded at U+00A0 no-break space (HTML:    ).

Text-processing software typically assumes that an automatic line break may be inserted anywhere a space character occurs; a non-breaking space prevents this from happening (provided the software recognizes the character). For example, if the text 100 km will not quite fit at the end of a line, the software may insert a line break between 100 and km. To avoid this undesirable behaviour, the editor may choose to use a non-breaking space between 100 and km. This guarantees that the text 100km will not be broken: if it does not fit at the end of a line it is moved in its entirety to the next line.

A second common application of non-breaking spaces is in plain text file formats such as SGML, HTML, TeX, and LaTeX, which sometimes treat sequences of whitespace characters (space, newline, tab, form feed, etc.) as if they were a single white-space character. Such collapsing of white-space allows the author to neatly arrange the source text using line breaks, indentation and other forms of spacing without affecting the final typeset result.[1][2]

In contrast, non-breaking spaces are not merged with neighboring whitespace characters, and can therefore be used by an author to insert additional visible space in the formatted text. For example, in HTML, non-breaking spaces may be used in conjunction with a fixed-width font to create tabular alignment (courier new font family used):

Column 1Column 2 ---------------- 1.22.3

(note that the use of the pre tag, the whitespace:pre CSS rule, or a table are alternative, if not necessarily better, ways to achieve the same result in HTML)

If ordinary spaces are used instead then the spaces are collapsed when the HTML is rendered and the layout is broken:

Column 1 Column 2 -------- -------- 1.2 2.3

Non-breaking space can also be used to automatically change formatting in a document. This is useful for things like class plans and recipe files where the description of a cell or line may be different from the actual text or title.

Unicode defines several other non-break space characters[3] that differ from the regular space in width:

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