Summarized test results:
HTML5, dir isolation

Intended audience: users, HTML coders, script developers, CSS coders, Web project managers, and anyone who wants to know the dir attribute works in current browsers.

These tests check whether user agents apply isolation around an element where the dir attribute is used, and treat it as a neutral character.

Section The dir attribute says that when values of dir are rtl or ltr "contents of the element are explicitly directionally isolated".

Section of the HTML5 specification, part of the section Requirements relating to the bidirectional algorithm, says "The following elements and attributes have requirements defined by the rendering section that, due to the requirements in this section, are requirements on all user agents (not just those that support the suggested default rendering)". Section 10.3.5 Bidirectional text expresses the expected rendering in terms of CSS.

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.

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


The tests do not use any vendor prefixes.

Basic dir isolation

With CSS shim

The results below are for tests that use some CSS that authors can apply to simulate the effect of isolation of the dir attribute. The Internationalization WG recommends that authors include that CSS for all their content until the dir attribute supports isolation by default.