In word processing and digital typesetting, a non-breaking space (" "), also known as a 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, the "common" non-breaking space is encoded as U+00A0 no-break space (HTML:
). Other width variations also exist.
Uses and variations
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" (according to the style guide) 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 "100 km" 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 treat sequences of whitespace characters (space, newline, tab, form feed, etc.) as if they were a single character. Such "collapsing" of whitespace allows the author to neatly arrange the source text using line breaks, indentation and other forms of spacing without affecting the final typeset result.
In contrast, non-breaking spaces are not merged with neighboring whitespace characters when displayed, and can therefore be used by an author to insert additional visible space in the resulting output. Conversely, indiscriminate use (see the recommended use in style guides), in addition to a normal space, gives extraneous extra space in the output.
Other non-breaking variants, defined in Unicode:
- U+2007 figure space (HTML:
). Produces a space somewhat equal to the figures (0–9) characters.
- U+202F narrow no-break space (HTML:
NNBSP). It was introduced in Unicode 3.0 for Mongolian, to separate a suffix from the word stem without indicating a word boundary. Also required for French (before ?, ! or ;) and Russian (before —) punctuation.
- U+2060 word-joiner (HTML:
WJ): encoded in Unicode since version 3.2. The word-joiner does not produce any space and prohibits a line break on either side of it. As its name more clearly suggests, it is a non-breaking word separator (It replaces the U+FEFF character, which is deprecated for such usage).
|Format||Representation of non-breaking space|
|Unicode and ISO/IEC 10646||U+00A0 no-break space (HTML:
Can be encoded in UTF-8 as
|CP1252 (MS Windows default in most countries using Germanic or Romance languages)||
|CP437, CP850, CP866||
|HTML (including Wikitext)||Character entity reference:
Numeric character references:
Unicode defines several other non-break space characters. See #Width variation. Encoding remarks:
- Word joiner, encoded in Unicode 3.2 and above as U+2060, and in HTML as
- The Byte Order Mark, U+FEFF, officially named "Zero Width No-Break Space", can also be used with the same meaning as the word joiner, but in current documents this use is deprecated. See also Zero-width non-breaking space.
Keyboard entry methods
It is rare for national or international standards on keyboard layouts to define an input method for the non-breaking space. An exception is the Finnish multilingual keyboard, accepted as the national standard SFS 5966 in 2008. According to the SFS setting, the non-breaking space can be entered with the key combination AltGr + Space.
|Microsoft Windows||Alt+0+1+6+0 or Alt+2+5+5 (doesn't always work)|
|Apple Mac OS X||⌥ Opt+Space|
|Linux or Unix using X11||Compose, Space, Space|
|GNU Emacs||Ctrl+X 8 Space|
|Vim||Ctrl+K, Space, Space; or Ctrl+K, ⇧ Shift+N, ⇧ Shift+S|
|Dreamweaver, LibreOffice, Microsoft Word,
OpenOffice.org (since 3.0)
|FrameMaker, LyX, OpenOffice.org (before 3.0),
|Mac Adobe InDesign||⌥ Opt+⌘ Cmd+X|
Apart from this, applications and environments often have methods of entering unicode entities directly via their code point, e.g. via the Alt Numpad input method. (Non-breaking space has codepoint 255 decimal (FF hex) in codepage 437 and codepage 850, and codepoint 160 decimal (A0 hex) in codepage 1252.)
- Hyphens in computing, for information about hard and non-breaking hyphens
- List of XML and HTML character entity references
- Orphans and widows
- Sentence spacing in digital media
- Space (punctuation)
- "Justify Just or Just Justify", M. Elyaakoubi and A. Lazrek. Journal of Electronic Publishing, vol. 13, issue 1, 2010. DOI 10.3998/3336451.0013.105.
- "Structure", HTML 4.01, W3, 1999-12-24.
- "Text", CSS 2.1, W3.
- Kotoistus (2006-12-28), Uusi näppäinasettelu [Status of the new keyboard layout] (presentation) (in Finnish, English), CSC – IT Center for Science. Drafts of the Finnish multilingual keyboard.