Whitespace visualization

Provides a way to visualize certain types of whitespace in the loaded documents. This behavior be controlled using the toggle-show-whitespace operation.

Supported characters

This currently supports the following whitespace characters (as defined by their Unicode code points):

  • Tab (U+0009, see Limitations below)

  • Line feed (U+000A, see Limitations below)

  • Carriage return (U+000D, see Limitations below)

  • Space (U+0020)

  • Next line (U+0085, see Limitations below)

  • Non-breaking space (U+00A0)

  • Soft hyphen (U+00AD, see Limitations below)

  • Mongolian vowel separator (U+180E, see Limitations below)

  • En quad (U+2000)

  • Em quad (U+2001)

  • En space (U+2002)

  • Em space (U+2003)

  • Three-per-em space (U+2004)

  • Four-per-em space (U+2005)

  • Six-per-em space (U+2006)

  • Figure space (U+2007)

  • Punctuation space (U+2008)

  • Thin space (U+2009)

  • Hair space (U+200A)

  • Word joiner (U+2060, see Limitations below)

  • Line separator (U+2028, see Limitations below)

  • Paragraph separator (U+2029, see Limitations below)

  • Narrow no-break space (U+202F)

  • Medium mathematical space (U+205F)

  • Ideographic space (U+3000)


Most browsers do not visualize a number of characters correctly, including tab, line feed and soft hyphen. Some browsers will visualize these using the glyph used for space, others (most notably Firefox, although this varies from character to character) don't show any glyph at all.

The zero-width space character is used by Fonto internally as a work-around to render cursor positions that are otherwise not visualized correctly by various browsers. Because of this, this character can not be visualized by this add-on.

If you use the outputClass CVK option and custom CSS to apply a different font-family to your content, whitespace within that content will not be visualized. As a work-around, you can add FontoXMLWhitespace as the first entry in the font-family stack, but this may change in a future release.