The zero-width space (ZWSP) is a non-printing character used in computerized typesetting to indicate word boundaries to text processing systems when using scripts that do not use explicit spacing, or after characters (such as the slash) that are not followed by a visible space but after which there may nevertheless be a line break. Normally, it is not a visible separation, but it may expand in passages that are fully justified.
In HTML pages, the zero-width space can be used as a potential line-break in long words as an alternative to the
<wbr> element. However, the zero-width space is not supported in some web browsers such as old versions of Internet Explorer (versions 6 and earlier).
To show the effect of the zero-width space, the following words have been separated with zero-width spaces:
And the following words are not separated with these spaces:
On browsers supporting zero-width spaces, resizing the window will re-break the first text only at word boundaries, while the second text will not be broken at all.
Blacklisting in URLs
ICANN rules prohibit domain names from including non-displayed characters such as zero-width space, and most browsers blacklist their use within domain names, because they can be used to create a homograph attack, where a malicious URL is visually indistinguishable from a legitimate one.
- Soft hyphen
- Word divider
- Word joiner
- Word wrapping
- Zero-width joiner
- Zero-width non-joiner
- Space (punctuation)
- Whitespace character - includes table comparing various space-like characters
- The Unicode Standard 6.1, p. 366
- "Alex Dunae » Better Web Typography with Spaces and Hyphens". Archived from the original on December 14, 2010. Retrieved December 3, 2009.CS1 maint: Unfit url (link)
- "Network.IDN.blacklist_chars - mozillaZine". Retrieved 2018-02-07.
- "Unicode Character 'ZERO WIDTH SPACE' - FileFormat.Info". Retrieved 2018-02-07.
- "General Punctuation – Unicode" (PDF). Retrieved 2013-07-20.
- "The LaTeX Companion. Chapter 3: Basic Formatting Tools" (PDF). Retrieved 2014-02-08.
- "groff(7) – Linux manual page". Retrieved 2014-02-08.