Web/CSS/ruby-align

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The ruby-align CSS property defines the distribution of the different ruby elements over the base.

/* Keyword values */
ruby-align: start;
ruby-align: center;
ruby-align: space-between;
ruby-align: space-around;

/* Global values */
ruby-align: inherit;
ruby-align: initial;
ruby-align: unset;

Syntax

Values

start

Is a keyword indicating that the ruby will be aligned with the start of the base text.

center

Is a keyword indicating that the ruby will be aligned at the middle of the base text.

space-between

Is a keyword indicating that the extra space will be distributed between the elements of the ruby.

space-around

Is a keyword indicating that the extra space will be distributed between the elements of the ruby, and around it.

Formal definition

Initial value	space-around
Applies to	ruby bases, ruby annotations, ruby base containers, ruby annotation containers
Inherited	yes
Computed value	as specified
Animation type	discrete

Formal syntax

start | center | space-between | space-around

Examples

Ruby aligned at the start of the base text

HTML

<ruby>
  <rb>This is a long text to check</rb>
  <rp>（</rp><rt>short ruby</rt><rp>）</rp>
</ruby>

CSS

ruby {
  ruby-align: start;
}

Ruby aligned at the center of the base text

HTML

<ruby>
  <rb>This is a long text to check</rb>
  <rp>（</rp><rt>short ruby</rt><rp>）</rp>
</ruby>

CSS

ruby {
  ruby-align: center;
}

Extra space distributed between ruby elements

HTML

<ruby>
  <rb>This is a long text to check</rb>
  <rp>（</rp><rt>short ruby</rt><rp>）</rp>
</ruby>

CSS

ruby {
  ruby-align: space-between;
}

Extra space distributed between and around ruby elements

HTML

<ruby>
  <rb>This is a long text to check</rb>
  <rp>（</rp><rt>short ruby</rt><rp>）</rp>
</ruby>

CSS

ruby {
  ruby-align: space-around;
}

Specifications

Specification	Status	Comment
CSS Ruby Layout Module Level 1The definition of 'ruby-align' in that specification.	Working Draft	Initial definition

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
ruby-align Experimental'	Chrome No support No	Edge No support No	Firefox Full support 38	IE No support No Notes' No support No Notes' Notes' Internet Explorer 9 and later supports an earlier draft of CSS Ruby with non-standard values for this property: auto, left, center, right, distribute-letter, distribute-space, and line-edge.	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android No support No	Firefox Android Full support 38	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No

Legend

Full support  

Full support

No support  

No support

Experimental. Expect behavior to change in the future.'

Experimental. Expect behavior to change in the future.

See implementation notes.'

See implementation notes.

See also

• HTML Ruby elements: <ruby>, <rt>, <rp>, and <rtc>.
• CSS Ruby properties: ruby-position, ruby-merge.

ruby-align by Mozilla Contributors is licensed under CC-BY-SA 2.5.