<rb>: The Ruby Base element

The HTML Ruby Base (<rb>) element is used to delimit the base text component of a  <ruby> annotation, i.e. the text that is being annotated. One <rb> element should wrap each separate atomic segment of the base text.

Content categories None.
Permitted content As a child of a <ruby> element.
Tag omission The end tag can be omitted if the element is immediately followed by an <rt><rtc>, or <rp> element or another <rb> element, or if there is no more content in the parent element.
Permitted parents A <ruby> element.
Permitted ARIA roles Any
DOM interface HTMLElement

Attributes

This element only includes the global attributes.

Usage notes

  • Ruby annotations are for showing pronunciation of East Asian characters, like using Japanese furigana or Taiwanese bopomofo characters. The <rb> element is used to separate out each segment of the ruby base text.
  • Even thought <rb> is not an empty element, it is common to just include the opening tag of each element in the source code, so that the ruby markup is less complex and easier to read. The browser can then fill in the full element in the rendered version.
  • You need to include one <rt> element for each base segment/<rb> element that you want to annotate.

Example

In this example, we provide an annotation for the original character equivalent of "Kanji":

<ruby>
  <rb>漢<rb>字
  <rp>(</rp><rt>kan<rt>ji<rp>)</rp>
</ruby>

Note how we've included two <rb> elements, to delimit the two separate parts of the ruby base text. The annotation on the other hand is delimited by two <rt> elements.

Note that we could also write this example with the two base text parts annotated completely separately. In this case we don't need to include <rb> elements:

<ruby>
  漢 <rp>(</rp><rt>Kan</rt><rp>)</rp>
  字 <rp>(</rp><rt>ji</rt><rp>)</rp>
</ruby>

The output looks like so:

The HTML above might look something like this when rendered by a browser without ruby support:

Note: See the article about the <ruby> element for further examples.

Specifications

Specification Status Comment
HTML5
The definition of '<rb>' in that specification.
Recommendation  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 5Edge No support NoFirefox Full support 38IE Full support 5Opera Full support 15Safari Full support 5WebView Android Full support YesChrome Android Full support YesEdge Mobile No support NoFirefox Android Full support 38Opera Android Full support 15Safari iOS Full support YesSamsung Internet Android Full support Yes

Legend

Full support  
Full support
No support  
No support

See also

Document Tags and Contributors

Contributors to this page: sideshowbarker, mfuji09, chrisdavidmills, fscholz
Last updated by: sideshowbarker,