Summarized test results:
HTML5, the ruby element and its children

Intended audience: users, HTML coders, script developers (PHP, JSP, etc.), Web project managers, and anyone who wants to know how browsers render ruby text.

These tests check whether user agents support styling and basic default positioning of markup based on ruby markup, including the elements ruby, rb, rt, and rtc.  They do not test the features of the CSS Ruby module, just whether the structure of the ruby markup is recognised by the browsers, and whether those minimal features needed to position the ruby text are available without CSS styling.

To see the test, click on the link in the left-most column. To see detailed results for a single test, click on a row and look just above the table. The detailed results show the date(s) the test result was recorded, and the version of the browser tested. The tables only show the results of the latest test. The detailed results may show additional tests on earlier versions of the same browser.

Any dependencies are shown in notes above the table, and notes below the table will usually provide any additional useful information, including an explanation of why a result was marked as 'partially successful'.


pass fail partially successful


Note that these test results are for released versions of the browsers tested. Versions that are still in development may provide better support for these features.

Ruby markup styling

Single-sided ruby position

Double-sided ruby


  1. ruby-double-005, Firefox 38.0.1: The numbers did not extend across all the base characters – just the first one.
  2. ruby-double-007, Firefox 38.0.1: The horizontal alignment of the ruby text was correct, but the two ruby texts overlap.

Ruby annotation gaps