Comparison of layout engines (HTML)

HTML
File:HTML.svg
HTML and HTML5 Dynamic HTML XHTML XHTML Mobile Profile and C-HTML Character encodings Font family HTML editor HTML element HTML scripting Layout engine Quirks mode Style sheets Unicode and HTML W3C Web colors Comparison of document markup languages web browsers layout engines for HTML HTML5 Non-standard HTML XHTML

The following tables compare HTML compatibility and support for a number of layout engines. Please see the individual products' articles for further information. This article is not all-inclusive or necessarily up-to-date. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs.

Only HTML 4 and XHTML 1.0 served as text/html (so called "HTML compatible" XHTML) are considered. XHTML 1.0 Strict is necessarily XHTML 1.1 with fewer elements and attributes deprecated. XHTML 2.0 is not considered as it is a redefinition of XHTML, which is not backward compatible. For more XHTML-related comparisons, please refer to comparison of layout engines (XHTML).

Version number, if possible, is provided for feature that is fully supported (based on HTML 4.01). Proprietary extensions are not included.

W3C deprecated tags and attributes and proprietary tags are compared in comparison of layout engines (Non-standard HTML).

Explanation of the tables

Engine nomenclature

Rather than the names of web browsers, the names of the underlying engines are used. The browsers that use the various engines are listed below.

Layout engine	Used by
Trident	Internet Explorer and other Internet Explorer shells (Microsoft Windows operating systems only)
Tasman	Mac OS X versions of Internet Explorer and MSN
Gecko	All Mozilla software, including Firefox; SeaMonkey; Galeon; Camino; K-Meleon; Flock; also Epiphany-gecko
WebKit	Apple Safari; Google Chrome; Shiira; iCab 4; OmniWeb 5.5+; Epiphany; Adobe AIR; Midori; Adobe Dreamweaver CS4
KHTML	Konqueror
Presto	Opera; Opera Mobile, Nintendo DS Browser; Internet Channel; future Adobe Systems products
iCab	iCab 1-3
Prince XML	Prince

Values

Values indicate the level of support in the most recent version of the layout engine, or (if a version number is given) in the specified version. Version numbers without any other value indicate the version at which the layout engine first fully supported the feature.

Value	Meaning
Yes	Indicates that the layout engine fully supports this property/element when valid values are used.
No	Indicates that the property/element is completely ignored.
Partial	Indicates that the property/element is understood, but that not all values are supported. Supported values are implemented correctly.
Incorrect	Indicates that the property/element is understood, but that it is not implemented correctly in all cases.
Experimental	Indicates that the property/element is understood, but supported under an alternate name. May be incomplete or buggy.
Dropped	Indicates that the property/element is no longer supported.
Nightly build	Indicates that the property/element is supported to some extent in an experimental/nightly build. Future support is expected.

Global structure elements

The global structure of the document.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Basic structure
html	5.0	Yes	1.0	Yes	Yes	7.0	Yes
head	4.0
body
Metadata
title	4.0	Yes	1.0	Yes	Yes	7.0	Yes
meta
Headings
h1	4.0	Yes	1.0	Yes	Yes	7.0	Yes
h2
h3
h4
h5
h6
Grouping elements
div	4.0	Yes	1.0	Yes	Yes	7.0	Yes
span

Text elements

Elements that represent text.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Phrase
em	4.0	Yes	1.0	Yes	Yes	7.0	Yes
strong
dfn
code
samp
kbd
var
cite
acronym
abbr	7.0
Quotations
blockquote	4.0	Yes	1.0	Yes	Yes	7.0	Yes
q	8.0		1.8
Subscripts and superscripts
sub	4.0	Yes	1.0	Yes	Yes	7.0	Yes
sup
Lines and paragraphs
p	4.0	Yes	1.0	Yes	Yes	7.0	Yes
pre
br	5.0
Marking document changes
ins	4.0	Yes	1.0	Yes	Yes	7.0	Yes
del

Gecko text element notes

1. q — Does not support nested quotes prior to 1.8.

Trident text element notes

1. q — Internet Explorer Version 8 features support for the "q" tag, among other things.

List elements

Elements that represent lists of information.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Unordered and ordered lists
ul	4.0	Yes	1.0	Yes	Yes	7.0	Yes
ol
li
Definition lists
dl	4.0	Yes	1.0	Yes	Yes	7.0	Yes
dt
dd

Table elements

Elements that represent tabular information.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Basic table elements
table	4.0	Yes	1.0	Yes	Yes	7.0	Yes
caption
tr
th
td
Row groups
thead	4.0	Yes	1.0	Yes	Yes	7.0	Yes
tbody
tfoot							?
Column groups
colgroup	4.0	?	1.0	Yes	Yes	7.0	Yes
col

Link elements

Hyperlinks, one of the primary forces driving the success of the World Wide Web.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
a	4.0	Yes	1.0	Yes	Yes	7.0	Yes
link
base

Multimedia elements

Multimedia features including images, applets, video clips, and other HTML documents.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Images
img	4.0	Yes	1.0	Yes	Yes	7.0	Yes
Generic inclusion
object	8.0	Yes	1.0	Yes	Yes	7.0	Yes
param	6.0
Image maps
map	4.0	Yes	1.0	Yes	Yes	7.0	Yes
area	5.0

Trident multimedia element notes

1. object — For images, a frame will be added to the object. Other content types are not supported and the element is incorrectly implemented as an ActiveX wrapper. Nested objects fallback mechanism is not supported prior to version 7.

Frame elements

Elements to present documents in multiple views, which may be independent windows or subwindows. Frame layout is only available in the frameset profiles. All frames are not available in XHTML 1.1 (use generic object elements instead for inline frames).

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Frame layout
frameset	4.0	Yes	1.0	Yes	Yes	7.0	Yes
frame
noframes
Inline frames
iframe	4.0	Yes	1.0	Yes	Yes	7.0	Yes

Form elements

The user interface controls for interacting with the web server.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Basic structure
form	4.0	Yes	1.0	Yes	Yes	7.0	Yes
fieldset
legend
Form controls and labels
button	4.0	Yes	1.0	Yes	Yes	7.0	Yes
textarea	4.0
input
label					3.4.2
List boxes (combo boxes)
select	4.0	Yes	1.0	Yes	Yes	7.0	Yes
optgroup
option

KHTML form elements notes

1. label — Focusable prior to 3.4.2.

Trident form elements notes

1. button — Value attribute is not supported; innerHTML/CDATA is returned instead.

Presentational elements

Elements that specify presentational information. Although not all elements are deprecated, their use is discouraged in favor of stylesheets. Deprecated elements are not available in the strict profiles and XHTML 1.1.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Font styles
b	4.0	Yes	1.0	Yes	Yes	7.0	Yes
i
big
small
tt
Horizontal rules
hr	4.0	Yes	1.0	Yes	Yes	7.0	Yes

Stylesheet elements

The ways to apply stylesheets (CSS) to the document.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Using link element	4.0	Yes	1.0	Yes	Yes	7.0	Yes
style	Incorrect

Trident language element notes

1. style — Limited to 32 style elements.

Script elements

Elements for embedding client-side script (JavaScript). See also DOM Events for a list of attributes used to attach an event handler to an element.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
script	5.0	Yes	1.0	Yes	Yes	7.0	Yes
noscript	Incorrect		Yes			Yes

Trident language element notes

1. noscript — Doesn't hide CSS backgrounds and borders on a noscript element when scripting is enabled.

Language elements

Elements related to language information.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
bdo	5.0	?	1.0	Yes	Partial	7.0	?

KHTML language element notes

1. bdo — While alphabetic and alphanumeric words are affected, numeric (numbers only) words are not.

Generic attributes

Attributes that can be used in any elements.

	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
Element identifiers
id	3.0	Yes	1.0	Yes	Yes	7.0	Yes
class
Inline styles
style	3.0	Yes	1.0	Yes	Yes	7.0	Yes
Advisory information
title	4.0	Yes	1.0	Yes	Yes	7.0	Yes
Language information
lang	4.0	Yes	1.0	Yes	Yes	7.0	Yes
dir	5.0

References

• "MSDN Library". CSS Enhancements in Internet Explorer 6. http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnie60/html/cssenhancements.asp. Retrieved May 1 2005. 
• "Mozilla Developer Documentation". Mozilla's DOCTYPE sniffing. http://www.mozilla.org/docs/web-developer/quirks/doctypes.html. Retrieved May 1 2005. 
• "Opera Documentation". The Opera 7 and 8 DOCTYPE Switches. http://www.opera.com/docs/specs/doctype/. Retrieved May 1 2005. 
• "Opera Documentation". Specification support - HTML. http://www.opera.com/docs/specs/html/. Retrieved May 1 2005. 
• "O'Reilly Network". Use the Right Doctype. http://www.oreillynet.com/pub/a/network/2000/04/14/doctype/. Retrieved May 1 2005. 
• "Apple Developer Connection". Safari HTML Reference. http://developer.apple.com/documentation/AppleApplications/Reference/SafariHTMLRef/. Retrieved July 14 2005. 

External links

• webref.info HTML Reference
• Activating the Right Layout Mode Using the Doctype Declaration
• Doctypes and their respective layout mode
• HTML Support History
• Web browser HTML support
• W3Schools XHTML 1.0 Reference