Hyphenation rules are language-specific. In HTML, the language is determined by the lang attribute, and browsers will hyphenate only if this attribute is present and the appropriate hyphenation dictionary is available. In XML, the xml:lang attribute must be used.

If supported, hyphenate-character may be used to specify an alternative hyphenation character to use at the end of the line being broken.

/* Keyword values */
hyphens: none;
hyphens: manual;
hyphens: auto;

/* Global values */
hyphens: inherit;
hyphens: initial;
hyphens: revert;
hyphens: revert-layer;
hyphens: unset;

The hyphens property is specified as a single keyword value chosen from the list below.

none

Words are not broken at line breaks, even if characters inside the words suggest line break points. Lines will only wrap at whitespace.

manual

Words are broken for line-wrapping only where characters inside the word suggest line break opportunities. See Suggesting line break opportunities below for details.

auto

The browser is free to automatically break words at appropriate hyphenation points, following whatever rules it chooses. However, suggested line break opportunities (see Suggesting line break opportunities below) will override automatic break point selection when present.

There are two Unicode characters used to manually specify potential line break points within text:

U+2010 (HYPHEN)

The "hard" hyphen character indicates a visible line break opportunity. Even if the line is not actually broken at that point, the hyphen is still rendered.

U+00AD (SHY)

An invisible, "soft" hyphen. This character is not rendered visibly; instead, it marks a place where the browser should break the word if hyphenation is necessary. In HTML, use ­ to insert a soft hyphen.

hyphens = 
  none    |
  manual  |
  auto    

This example uses three classes, one for each possible configuration of the hyphens property.

HTML

<dl>
  <dt><code>none</code>: no hyphen; overflow if needed</dt>
  <dd lang="en" class="none">An extreme&shy;ly long English word</dd>
  <dt>
    <code>manual</code>: hyphen only at &amp;hyphen; or &amp;shy; (if needed)
  </dt>
  <dd lang="en" class="manual">An extreme&shy;ly long English word</dd>
  <dt><code>auto</code>: hyphens where the algorithm decides (if needed)</dt>
  <dd lang="en" class="auto">An extreme&shy;ly long English word</dd>
</dl>

CSS

dd {
  width: 55px;
  border: 1px solid black;
}
dd.none {
  hyphens: none;
}
dd.manual {
  hyphens: manual;
}
dd.auto {
  hyphens: auto;
}

Result

• content
• overflow-wrap (formerly word-wrap)
• word-break
• Guide to wrapping and breaking text