The following tables compare XHTML 1.1 compatibility and support for a number of layout engines.

XHTML 1.1 which is mainly a modularization of XHTML 1.0, is composed of 20 element modules (7 of which are submodules), including the additional Ruby Annotation Module, and two attribute modules (Server-side Image Map Module and Intrinsic Events Module).

Explanation of tables

See list of layout engines for the full list.

Values

These indicate the level of support for the given item in each engine. By default, the most recent version of the engine is implied. However, a specific version number can be listed; when this indicates full support, it's the initial version of the engine fully supporting the item.

Legend
Value	Meaning
Yes	Fully supported
No	Has never been supported
Partial	Only some values are supported
Incorrect	Not implemented correctly in all cases
Experimental	May be incomplete or buggy
Nightly build	Currently in development; full support is expected
Depends	Only supported for the specified conditions
Dropped	No longer supported

Elements

Core Modules

Structure Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`body`	<3.1^{[IE 1.0]} ^[1]	Yes	Yes	Yes	Yes	Yes	Yes
`head`	<3.1^{[IE 1.0]} ^[1]
`html`	<3.1^{[IE 1.0]} ^[2]
`title`	<3.1^{[IE 1.0]} ^[3]

Text Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`abbr`	Yes^{[citation needed]}	Yes	Yes	Yes	Yes	Yes	Yes
`acronym`	<3.1^{[IE 4.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`address`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`blockquote`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`br`	<3.1^{[IE 1.0]} ^[5]	Yes	Yes	Yes	Yes	Yes	Yes
`cite`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`code`		Yes	Yes	Yes	Yes	Yes	Yes
`dfn`		Yes	Yes	Yes	Yes	Yes	Yes
`div`	<3.1^{[IE 3.0]} ^[6]	Yes	Yes	Yes	Yes	Yes	Yes
`em`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`h1`		Yes	Yes	Yes	Yes	Yes	Yes
`h2`		Yes	Yes	Yes	Yes	Yes	Yes
`h3`		Yes	Yes	Yes	Yes	Yes	Yes
`h4`		Yes	Yes	Yes	Yes	Yes	Yes
`h5`		Yes	Yes	Yes	Yes	Yes	Yes
`h6`		Yes	Yes	Yes	Yes	Yes	Yes
`kbd`		Yes	Yes	Yes	Yes	Yes	Yes
`p`	<3.1^{[IE 1.0]} ^[5]	Yes	Yes	Yes	Yes	Yes	Yes
`pre`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`q`	<3.1^{[IE 4.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`samp`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`span`	<3.1^{[IE 3.0]} ^[6]	Yes	Yes	Yes	Yes	Yes	Yes
`strong`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes
`var`	<3.1^{[IE 1.0]} ^[4]	Yes	Yes	Yes	Yes	Yes	Yes

Hypertext Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`a`	<3.1^{[IE 1.0]} ^[5]	Yes	Yes	Yes	Yes	Yes	Yes

List Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`dl`	<3.1^{[IE 1]} ^[7]	Yes	Yes	Yes	Yes	Yes	Yes
`dt`
`dd`
`ol`
`ul`
`li`

Text Extension Modules

Presentation Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`b`	<3.1^{[IE 1]} ^[6]	Yes	Yes	Yes	Yes	Yes	Yes
`big`	<3.1^{[IE 3]} ^[6]
`hr`	<3.1^{[IE 1]} ^[8]
`i`	<3.1^{[IE 1]} ^[6]
`small`	<3.1^{[IE 3]} ^[6]
`sub`
`sup`
`tt`	Yes

Edit Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`del`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
`ins`	Yes	Yes	Yes	Yes	Yes	Yes	Yes

Bi-directional Text Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`bdo`	<3.1^{[IE 5.0]} ^[6]	?	Yes	Yes	Partial	Yes	?

Forms Modules

Forms Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`form`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
`input`
`select`
`option`
`textarea`
`button`
`fieldset`
`label`
`legend`
`optgroup`

Table Modules

Table Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`caption`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
`table`
`td`
`th`
`tr`
`col`		?
`colgroup`		?
`tbody`		Yes
`thead`
`tfoot`							?

Image Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`img`	<3.1^{[IE 1.0]} ^[8]	Yes	Yes	Yes	Yes	Yes	Yes

Client-side Image Map Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`area`	<3.1^{[IE 1.0]} ^[8]	Yes	Yes	Yes	Yes	Yes	Yes
`map`	<3.1^{[IE 1.0]} ^[8]	Yes	Yes	Yes	Yes	Yes	Yes

Object Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`object`	<3.1^{[IE 3.0]} ^[8]	Yes	Yes	Yes	Yes	Yes	Yes
`param`	<3.1^{[IE 3.0]} ^[8]	Yes	Yes	Yes	Yes	Yes	Yes

Metainformation Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`meta`	<3.1^{[IE 2.0]} ^[3]	Yes	Yes	Yes	Yes	Yes	Yes

Scripting Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`script`	<3.1^{[IE 3.0]} ^[2]	Yes	Yes	Yes	Yes	Yes	Yes
`noscript`	<3.1^{[IE 3.0]} ^[2]^{[citation needed]}	Yes	Yes	Yes	Yes	Yes	Yes

Style Sheet Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`style`	<3.1^{[IE 3.0]} ^[2]^{[note 1]}	Yes	Yes	Yes	Yes	Yes	Yes

Link Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`link`	<3.1^{[IE 3.0]} ^[3]	Yes	Yes	Yes	Yes	Yes	Yes

Base Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`base`	<3.1^{[IE 1.0]} ^[3]	Yes	Yes	Yes	Yes	Yes	Yes

Ruby Annotation Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`ruby`	Yes	No	Yes	Yes	No	No	No
`rbc`	No			No
`rtc`	No			No
`rb`	Yes			Yes
`rt`	Yes			Yes
`rp`	No			No

Attributes

Core

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`class`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
`id`
`title`

I18N

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`dir`	Yes	Yes	Yes	Yes	Yes	Yes	Yes
`xml:lang`	?	?	?	?	?	?	?

Events

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Mouse
`onclick`	?	?	?	?	?	?	?
`ondblclick`
`onmousedown`
`onmouseup`
`onmouseover`
`onmousemove`
`onmouseout`
Keyboard
`onkeypress`	?	?	?	?	?	?	?
`onkeydown`
`onkeyup`

Server-side Image Map Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
`ismap`	?	?	?	?	?	?	?

Intrinsic Events Module

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Structure Module
`onload`	?	?	?	?	?	?	?
`onunload`	?	?	?	?	?	?	?
Forms Module
`onchange`	?	?	?	?	?	?	?
`onblur`
`onfocus`
`onreset`
`onselect`
`onsubmit`