Copyright © 2010 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
HTML5 defines the fifth major revision of the core language of the World Wide Web, HTML. "HTML5 differences from HTML4" describes the differences between HTML4 and HTML5 and provides some of the rationale for the changes. This document may not provide accurate information as the HTML5 specification is still actively in development. When in doubt, always check the HTML5 specification itself. [HTML5]
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This is the 19 October 2010 W3C Working Draft produced by the HTML Working Group, part of the HTML Activity. The Working Group intends to publish this document as a Working Group Note to accompany the HTML5 specification. The appropriate forum for comments is public-html-comments@w3.org, a mailing list with a public archive.
Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
HTML has been in continuous evolution since it was introduced to the Internet in the early 1990s. Some features were introduced in specifications; others were introduced in software releases. In some respects, implementations and author practices have converged with each other and with specifications and standards, but in other ways, they continue to diverge.
HTML4 became a W3C Recommendation in 1997. While it continues to serve as a rough guide to many of the core features of HTML, it does not provide enough information to build implementations that interoperate with each other and, more importantly, with a critical mass of deployed content. The same goes for XHTML1, which defines an XML serialization for HTML4, and DOM Level 2 HTML, which defines JavaScript APIs for both HTML and XHTML. HTML5 will replace these documents. [DOM2HTML] [HTML4] [XHTML1]
The HTML5 draft reflects an effort, started in 2004, to study contemporary HTML implementations and deployed content. The draft:
HTML5 is still a draft. The contents of HTML5, as well as the contents of this document which depend on HTML5, are still being discussed on the HTML Working Group and WHATWG mailing lists. The open issues are linked from the HTML5 draft.
HTML5 is defined in a way that it is backwards compatible with the way user agents handle deployed content. To keep the authoring language relatively simple for authors several elements and attributes are not included as outlined in the other sections of this document, such as presentational elements that are better dealt with using CSS.
User agents, however, will always have to support these older elements
and attributes and this is why the HTML5 specification clearly separates
requirements for authors and user agents. For instance, this means that
authors cannot use the isindex
or the plaintext
element, but user agents are required to support them in a way that is
compatible with how these elements need to behave for compatibility with
deployed content.
Since HTML5 has separate conformance requirements for authors and user agents there is no longer a need for marking features "deprecated".
The HTML5 specification will not be considered finished before there are at least two complete implementations of the specification. A test suite will be used to measure completeness of the implementations. This approach differs from previous versions of HTML, where the final specification would typically be approved by a committee before being actually implemented. The goal of this change is to ensure that the specification is implementable, and usable by authors once it is finished.
HTML5 defines an HTML syntax that is compatible with HTML4 and XHTML1
documents published on the Web, but is not compatible with the more
esoteric SGML features of HTML4, such as processing
instructions and shorthand
markup as these are not supported by most user agents. Documents using
the HTML syntax are almost always served with the text/html
media type.
HTML5 also defines detailed parsing rules (including "error handling")
for this syntax which are largely compatible with popular implementations.
User agents must use these rules for resources that have the
text/html
media type. Here is an example document that
conforms to the HTML syntax:
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>Example document</title>
</head>
<body>
<p>Example paragraph</p>
</body>
</html>
HTML5 also defines a text/html-sandboxed
media type for
documents using the HTML syntax. This can be used when hosting untrusted
content.
The other syntax that can be used for HTML5 is XML. This syntax is
compatible with XHTML1 documents and implementations. Documents using this
syntax need to be served with an XML media type and elements need to be
put in the http://www.w3.org/1999/xhtml
namespace following
the rules set forth by the XML specifications. [XML]
Below is an example document that conforms to the XML syntax of HTML5.
Note that XML documents must be served with an XML media type such as
application/xhtml+xml
or application/xml
.
<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Example document</title>
</head>
<body>
<p>Example paragraph</p>
</body>
</html>
For the HTML syntax of HTML5, authors have three means of setting the character encoding:
Content-Type
header for instance.
meta
element with a charset
attribute that specifies the encoding within the first 512 bytes of the
document. E.g. <meta charset="UTF-8">
could be used to
specify the UTF-8 encoding. This replaces the need for <meta
http-equiv="Content-Type" content="text/html; charset=UTF-8">
although that syntax is still allowed.
For the XML syntax, authors have to use the rules as set forth in the XML specifications to set the character encoding.
The HTML syntax of HTML5 requires a DOCTYPE to be specified to ensure that the browser renders the page in standards mode. The DOCTYPE has no other purpose and is therefore optional for XML. Documents with an XML media type are always handled in standards mode. [DOCTYPE]
The DOCTYPE declaration is <!DOCTYPE html>
and is
case-insensitive in the HTML syntax. DOCTYPEs from earlier versions of
HTML were longer because the HTML language was SGML-based and therefore
required a reference to a DTD. With HTML5 this is no longer the case and
the DOCTYPE is only needed to enable standards mode for documents written
using the HTML syntax. Browsers already do this for <!DOCTYPE
html>
.
The HTML syntax of HTML5 allows for MathML and SVG elements to be used inside a document. E.g. a very simple document using some of the minimal syntax features could look like:
<!doctype html>
<title>SVG in text/html</title>
<p>
A green circle:
<svg> <circle r="50" cx="50" cy="50" fill="green"/> </svg>
</p>
More complex combinations are also possible. E.g. with the SVG
foreignObject
element you could nest MathML, HTML, or both
inside an SVG fragment that is itself inside HTML.
There are a few other syntax changes worthy of mentioning:
lang
attribute takes the empty string in addition to
a valid language identifier, just like xml:lang
does in XML.
This section is split up in several subsections to more clearly illustrate the various differences there are between HTML4 and HTML5.
The links in this section may stop working if elements are renamed and/or removed. They should function in the latest version of this draft.
The following elements have been introduced for better structure:
section
represents a generic document or application section. It can be used together with the
h1
, h2
, h3
, h4
,
h5
, and h6
elements to indicate the document
structure.
article
represents an independent piece of content of a document, such as a blog
entry or newspaper article.
aside
represents a piece of content that is only slightly related to the rest
of the page.
hgroup
represents the header of a section.
header
represents a group of introductory or navigational aids.
footer
represents a footer for a section and can contain information about the
author, copyright information, et cetera.
nav
represents a section of the document intended for navigation.
figure
represents a piece of self-contained flow content, typically referenced
as a single unit from the main flow of the document.
<figure>
<video src="ogg"></video>
<figcaption>Example</figcaption>
</figure>
figcaption
can be used as caption (it is optional).
Then there are several other new elements:
video
and audio
for multimedia content. Both provide an API so application authors can
script their own user interface, but there is also a way to trigger a
user interface provided by the user agent. source
elements are used together with these elements if there are multiple
streams available of different types.
embed
is used for plugin content.
mark
represents represents a run of text in one document marked or
highlighted for reference purposes, due to its relevance in another
context.
progress
represents a completion of a task, such as downloading or when
performing a series of expensive operations.
meter
represents a measurement, such as disk usage.
time
represents a date and/or time.
wbr
represents a line break opportunity.
canvas
is used for rendering dynamic bitmap graphics on the fly, such as graphs
or games.
command
represents a command the user can invoke.
details
represents additional information or controls which the user can obtain
on demand. The summary
element provides its summary, legend, or caption.
datalist
together with the a new list
attribute for
input
can be used to make comboboxes:
<input list="browsers">
<datalist id="browsers">
<option value="Safari">
<option value="Internet Explorer">
<option value="Opera">
<option value="Firefox">
</datalist>
keygen
represents control for key pair generation.
output
represents some type of output, such as from a calculation done through
scripting.
The input
element's type
attribute now has the
following new values:
The idea of these new types is that the user agent can provide the user interface, such as a calendar date picker or integration with the user's address book, and submit a defined format to the server. It gives the user a better experience as his input is checked before sending it to the server meaning there is less time to wait for feedback.
HTML5 has introduced several new attributes to various elements that were already part of HTML4:
The a
and area
elements now have a
media
attribute for consistency with the link
element.
The area
element, for consistency with the a
and link
elements, now also has the hreflang
and rel
attributes.
The base
element can now have a target
attribute as well, mainly for consistency with the a
element. (This is already widely supported.) Also, the
target
attribute for the a
and
area
elements is no longer deprecated, as it is useful in
Web applications, e.g. in conjunction with iframe
.
The value
attribute for the li
element is no
longer deprecated as it is not presentational. The same goes for the
start
attribute of the ol
element.
The meta
element has a charset
attribute now
as this was already widely supported and provides a nice way to specify
the character encoding for the
document.
A new autofocus
attribute can be specified on the
input
(except when the type
attribute is
hidden
), select
, textarea
and
button
elements. It provides a declarative way to focus a
form control during page load. Using this feature should enhance the
user experience as the user can turn it off if the user does not like
it, for instance.
A new placeholder
attribute can be specified on the
input
and textarea
elements. It represents a
hint intended to aid the user with data entry.
<input type=email placeholder="a@b.com">
The new form
attribute for input
,
output
, select
, textarea
,
button
and fieldset
elements allows for
controls to be associated with a form. I.e. these elements can now be
placed anywhere on a page, not just as descendants of the
form
element.
<label>Email:
<input type=email form=x name=email>
</label>
<form id=x></form>
The new required
attribute applies to input
(except when the type
attribute is hidden
,
image
or some button type such as submit
) and
textarea
. It indicates that the user has to fill in a value
in order to submit the form.
The fieldset
element now allows the disabled
attribute. It disables all descendant controls when specified.
The input
element has several new attributes to specify
constraints: autocomplete
, min
,
max
, multiple
, pattern
and
step
. As mentioned before it also has a new
list
attribute which can be used together with the
datalist
element.
The form
element has a novalidate
attribute
that can be used to disable form validation submission (i.e. the form
can always be submitted).
The input
and button
elements have
formaction
, formenctype
,
formmethod
, formnovalidate
, and
formtarget
as new attributes. If present, they override the
action
, enctype
, method
,
novalidate
, and target
attributes on the
form
element.
The menu
element has two new attributes:
type
and label
. They allow the element to
transform into a menu as found in typical user interfaces as well as
providing for context menus in conjunction with the global
contextmenu
attribute.
The style
element has a new scoped
attribute
which can be used to enable scoped style sheets. Style rules within such
a style
element only apply to the local tree.
The script
element has a new attribute called
async
that influences script loading and execution.
The html
element has a new attribute called
manifest
that points to an application cache manifest used
in conjunction with the API for offline Web applications.
The link
element has a new attribute called
sizes
. It can be used in conjunction with the
icon
relationship (set through the rel
attribute; can be used for e.g. favicons) to indicate the size of the
referenced icon. Thus allowing for icons of distinct dimensions.
The ol
element has a new attribute called
reversed
. When present, it indicates that the list order is
descending.
The iframe
element has three new attributes called
sandbox
, seamless
, and srcdoc
which allow for sandboxing content, e.g. blog comments.
Several attributes from HTML4 now apply to all elements. These are
called global attributes: class
, dir
,
id
, lang
, style
,
tabindex
and title
.
There are also several new global attributes:
contenteditable
attribute indicates that the element
is an editable area. The user can change the contents of the element and
manipulate the markup.
contextmenu
attribute can be used to point to a
context menu provided by the author.
data-*
collection of author-defined
attributes. Authors can define any attribute they want as long as they
prefix it with data-
to avoid clashes with future versions
of HTML. The only requirement on these attributes is that they are not
used for user agent extensions.
draggable
attribute can be used together with the new
drag & drop API.
hidden
attribute indicates that an element is not
yet, or is no longer, relevant.
role
and aria-*
collection
attributes which can be used to instruct assistive technology.
spellcheck
attribute allows for hinting whether
content can be checked for spelling or not.
HTML5 also makes all event handler attributes from HTML4, which take the
form onevent-name
, global attributes and adds
several new event handler attributes for new events it defines. E.g. the
play
event which is used by the API for the media elements
(video
and audio
).
These elements have slightly modified meanings in HTML5 to better reflect how they are used on the Web or to make them more useful:
The a
element without an href
attribute now
represents a placeholder for where a link otherwise might have been
placed. It can also contain flow content rather than being restricted to
phrase content.
The address
element is now scoped by the new concept of
sectioning.
The b
element now represents a span of text to be
stylistically offset from the normal prose without conveying any extra
importance, such as keywords in a document abstract, product names in a
review, or other spans of text whose typical typographic presentation is
emboldened.
The cite
element now solely represents the title of a
work (e.g. a book, a paper, an essay, a poem, a score, a song, a script,
a film, a TV show, a game, a sculpture, a painting, a theatre
production, a play, an opera, a musical, an exhibition, a legal case
report, etc). Specifically the example in HTML4 where it is used to mark
up the name of a person is no longer considered conforming.
The hr
element now represents a paragraph-level thematic
break.
The i
element now represents a span of text in an
alternate voice or mood, or otherwise offset from the normal prose, such
as a taxonomic designation, a technical term, an idiomatic phrase from
another language, a thought, a ship name, or some other prose whose
typical typographic presentation is italicized. Usage varies widely by
language.
For the label
element the browser should no longer move
focus from the label to the control unless such behavior is standard for
the underlying platform user interface.
The menu
element is redefined to be useful for toolbars
and context menus.
The s
element now represents contents that are no longer
accurate or no longer relevant.
The small
element now represents small print (for side
comments and legal print).
The strong
element now represents importance rather than
strong emphasis.
The head
element no longer allows the object
element as child.
The type
attribute on script
and
style
is no longer required if the scripting language is
ECMAScript and the styling language is CSS respectively.
The following attributes are allowed but authors are discouraged from using them and instead strongly encouraged to use an alternative solution:
The border
attribute on img
. It is required
to have the value "0
" when present. Authors can use CSS
instead.
The language
attribute on script
. It is
required to have the value "JavaScript
" (case-insensitive)
when present and cannot conflict with the type
attribute.
Authors can simply omit it as it has no useful function.
The name
attribute on a
. Authors can use the
id
attribute instead.
The summary
attribute on table
. The HTML5
draft defines several alternative solutions.
The elements in this section are not to be used by authors. User agents
will still have to support them and various sections in HTML5 define how.
E.g. the obsolete isindex
element is handled by the parser
section.
The following elements are not in HTML5 because their effect is purely presentational and their function is better handled by CSS:
basefont
big
center
font
strike
tt
u
The following elements are not in HTML5 because using them damages usability and accessibility:
frame
frameset
noframes
The following elements are not included because they have not been used often, created confusion, or their function can be handled by other elements:
acronym
is not included because it has created a lot of
confusion. Authors are to use abbr
for abbreviations.
applet
has been obsoleted in favor of
object
.
isindex
usage can be replaced by usage of form controls.
dir
has been obsoleted in favor of ul
.
Finally the noscript
element is only conforming in the HTML
syntax. It is not included in the XML syntax as its usage relies on an
HTML parser.
Some attributes from HTML4 are no longer allowed in HTML5. The specification defines how user agents should process them in legacy documents, but authors must not use them and they will not validate.
HTML5 has advice on what you can use instead.
rev
and charset
attributes on
link
and a
.
shape
and coords
attributes on
a
.
longdesc
attribute on img
and
iframe
.
target
attribute on link
.
nohref
attribute on area
.
profile
attribute on head
.
version
attribute on html
.
name
attribute on img
(use id
instead).
scheme
attribute on meta
.
archive
, classid
, codebase
,
codetype
, declare
and standby
attributes on object
.
valuetype
and type
attributes on
param
.
axis
and abbr
attributes on td
and th
.
scope
attribute on td
.
In addition, HTML5 has none of the presentational attributes that were in HTML4 as their functions are better handled by CSS:
align
attribute on caption
,
iframe
, img
, input
,
object
, legend
, table
,
hr
, div
, h1
, h2
,
h3
, h4
, h5
, h6
,
p
, col
, colgroup
,
tbody
, td
, tfoot
, th
,
thead
and tr
.
alink
, link
, text
and
vlink
attributes on body
.
background
attribute on body
.
bgcolor
attribute on table
, tr
,
td
, th
and body
.
border
attribute on table
and
object
.
cellpadding
and cellspacing
attributes on
table
.
char
and charoff
attributes on
col
, colgroup
, tbody
,
td
, tfoot
, th
, thead
and tr
.
clear
attribute on br
.
compact
attribute on dl
, menu
,
ol
and ul
.
frame
attribute on table
.
frameborder
attribute on iframe
.
height
attribute on td
and th
.
hspace
and vspace
attributes on
img
and object
.
marginheight
and marginwidth
attributes on
iframe
.
noshade
attribute on hr
.
nowrap
attribute on td
and th
.
rules
attribute on table
.
scrolling
attribute on iframe
.
size
attribute on hr
.
type
attribute on li
, ol
and
ul
.
valign
attribute on col
,
colgroup
, tbody
, td
,
tfoot
, th
, thead
and
tr
.
width
attribute on hr
, table
,
td
, th
, col
, colgroup
and pre
.
HTML5 introduces a number of APIs that help in creating Web applications. These can be used together with the new elements introduced for applications:
video
and audio
elements.
contenteditable
attribute.
draggable
attribute.
HTMLDocument
HTML5 has extended the HTMLDocument
interface from DOM
Level 2 HTML in a number of ways. The interface is now implemented on
all objects implementing the Document
interface so
it stays meaningful in a compound document context. It also has several
noteworthy new members:
getElementsByClassName()
to select elements by their
class name. The way this method is defined will allow it to work for any
content with class
attributes and a Document
object such as SVG and MathML.
innerHTML
as an easy way to parse and serialize an HTML
or XML document. This attribute was previously only available on
HTMLElement
in Web browsers and not part of any standard.
activeElement
and hasFocus
to determine
which element is currently focused and whether the Document
has focus respectively.
getSelection()
which returns an object that represents
the current selection(s).
HTMLElement
The HTMLElement
interface has also gained several
extensions in HTML5:
getElementsByClassName()
which is basically a scoped
version of the one found on HTMLDocument
.
innerHTML
as found in Web browsers today. It is also
defined to work in XML context (when it is used in an XML document).
classList
is a convenient accessor for
className
. The object it returns, exposes methods
(contains()
, add()
, remove()
, and
toggle()
) for manipulating the element's classes. The
a
, area
and link
elements have a
similar attribute called relList
that provides the same
functionality for the rel
attribute.
The changelogs in this section indicate what has been changed between
publications of the HTML5 drafts. Rationale for changes can be found in
the public-html@w3.org
and whatwg@whatwg.org
mailing list archives, and the This Week in
HTML5 series of blog posts. More fundamental rationale is being
collected on the WHATWG Rationale wiki page. Many
editorial and minor technical changes are not included in these
changelogs. I.e. implementors are strongly encouraged to follow the
development of the main specification on a frequent basis so they become
aware of all changes that affect them early on.
The changes in the changelogs are in rough chronological order to ease editing this document.
hidden
attribute now works for table-related
elements.
canvas
getContext()
method is now
defined to be able to handle multiple contexts better.
startTime
IDL attribute was renamed
to initialTime
and startOffsetTime
was added.
prefetch
link relationship can now be used on
a
elements.
datetime
attribute of ins
and
del
no longer requires a time to be specified.
form
element
is no longer supported.
s
element is no longer deprecated.
video
element has a new audio
attribute.
Per usual, lots of other minor fixes have been made as well.
ping
attribute has been removed from the W3C version
of HTML5.
title
element is optional for iframe
srcdoc
documents and other scenarios where a title is
already available. As is the case with email.
keywords
is now a standard metadata name for the
meta
element.
allow-top-navigation
value has been added for the
sandbox
attribute on the iframe
element. It
allows the embedded content to navigate its parent when specified.
wbr
element has been added.
alternate
keyword for the rel
attribute
of the link
element can now be used to point to feeds again,
even if the feed is not an alternative for the document.
In addition lots of minor changes, clarifications, and fixes have been made to the document.
dialog
element has been removed. A section with
advice on how to mark up conversations has effectively replaced it.
document.head
has been introduced to provide convenient
access to the head
element from script.
feed
has been removed. alternate
with specific media types is to be
used instead.
createHTMLDocument()
has been introduced as API to allow
easy creation of HTML documents.
meter
and progress
elements no
longer have "magic" processing of their contents because it could not be
made to work internationally.
meter
and progress
elements, as well as
the output
element, can now be labeled using the
label
element.
text/html-sandboxed
, was introduced to
allow hosting of potentially hostile content without it causing harm.
srcdoc
attribute for the iframe
element
was introduced to allow embedding of potentially hostile content inline.
It is expected to be used together with the sandbox
and
seamless
attributes.
figure
element now uses a new element
figcaption
rather than legend
because people
want to use HTML5 long before it reaches W3C Recommendation.
details
element now uses a new element
summary
for exactly the same reason.
autobuffer
attribute on media elements was renamed to
preload
.
A whole lot of other smaller issues have also been resolved. The above list summarizes what is thought to be of primary interest to authors.
In addition to all of the above, Microdata, the 2D context API for
canvas
, and Web Messaging (postMessage()
API)
have been split into their own drafts at the W3C (the WHATWG still
publishes a version of HTML5 that includes them):
Specific microdata vocabularies are gone altogether in the W3C draft of HTML5 and are not published as a separate draft. The WHATWG draft of HTML5 still includes them.
time
element is empty user agents have to render
the time in a locale-specific manner.
load
event is dispatched at Window
, but
now has Document
as its target.
pushState()
now affects the Referer
(sic)
header.
onundo
and onredo
are now on
Window
.
startTime
member that indicates
where the current resource starts.
header
has been renamed to hgroup
and a new
header
element has been introduced.
createImageData()
now also takes ImageData
objects.
createPattern()
can now take a video
element
as argument too.
footer
element is no longer allowed in
header
and header
is not allowed in
address
or footer
.
<input type="tel">
accesskey
is now properly defined.
section
and article
now take a
cite
attribute.
textLength
has been added as member of the
textarea
element.
rp
element now takes phrasing content rather than a
single character.
location.reload()
is now defined.
hashchange
event now fires asynchronously.
spellcheck
IDL attribute now maps to a
DOMString
.
hasFeature()
support has been reduced to a minimum.
Audio()
constructor sets the autobuffer
attribute.
td
element is no longer allowed in
thead
.
input
element and DataTransfer
object
now have a files
IDL attribute.
datagrid
and bb
have been removed due to
their design not being agreed upon.
On top of this list quite a few minor clarifications, typos, issues specific to implementors, and other small problems have been resolved.
In addition, the following parts of HTML5 have been taken out and will likely be further developed at the IETF:
spellcheck
has been added.
this
in the global object returns
a WindowProxy
object rather than the Window
object.
value
IDL attribute for input
elements
in the File Upload state is now defined.
designMode
was changed to be more in line
with legacy implementations.
drawImage()
method of the 2D drawing API can now take
a video
element as well.
document.domain
is now IPv6-compatible.
video
element gained an autobuffer
boolean attribute that serves as a hint.
meta
element with a
charset
attribute in XML documents if the value of that
attribute matches the encoding of the document. (Note that it does not
specify the value, it is just a talisman.)
bufferingRate
and bufferingThrottled
members of media elements have been removed.
postMessage()
API now takes an array of
MessagePort
objects rather than just one.
add()
method on the
select
element and the options
member of the
select
element is now optional.
action
, enctype
, method
,
novalidate
, and target
attributes on
input
and button
elements have been renamed to
formaction
, formenctype
,
formmethod
, formnovalidate
, and
formtarget
.
document.cookie
and
localStorage
) at the same time. The Navigator
gained a getStorageUpdates()
method to allow it to be
explicitly released.
text/html
resources.
placeholder
attribute has been added to the
textarea
element.
keygen
element for key pair generation.
datagrid
element was revised to make the API more
asynchronous and allow for unloaded parts of the grid.
In addition, several parts of HTML5 have been taken out and will be further developed by the Web Applications Working Group as standalone specifications:
localStorage
and sessionStorage
)
data
member of ImageData
objects has
been changed from an array to a CanvasPixelArray
object.
canvas
element and its API.
canvas
is clarified.
canvas
have
been made in response to implementation and author feedback. E.g.
clarifying what happens when NaN and Infinity are passed and fixing the
definitions of arc()
and arcTo()
.
innerHTML
in XML was slightly changed to improve
round-tripping.
toDataURL()
method on the canvas
element
now supports setting a quality level when the media type argument is
image/jpeg
.
poster
attribute of the video
element
now affects its intrinsic dimensions.
type
attribute of the
link
element has been clarified.
link
when the expected type
is an image.
href
attribute of the
base
element does not depend on xml:base
.
xmlns
attribute with the value
http://www.w3.org/1999/xhtml
is now allowed on all HTML
elements.
data-*
attributes and custom attributes on the
embed
element now have to match the XML Name
production and cannot contain a colon.
volume
on media elements is now 1.0
rather than 0.5.
event-source
was renamed to eventsource
because no other HTML element uses a hyphen.
postMessage()
.
bb
has been added. It represents a
user agent command that the user can invoke.
addCueRange()
method on media elements has been
modified to take an identifier which is exposed in the callbacks.
parent
attribute of the Window
object is
now defined.
embed
element is defined to do extension sniffing for
compatibility with servers that deliver Flash as text/plain
.
(This is marked as an issue in the specification to figure out if there
is a better way to make this work.)embed
can now be used without its src
attribute.
getElementsByClassName()
is defined to be ASCII
case-insensitive in quirks mode for consistency with CSS.
localName
no longer returns the node
name in uppercase.
data-*
attributes are defined to be always
lowercase.
opener
attribute of the Window
object is
not to be present when the page was opened from a link with
target="_blank"
and rel="noreferrer"
.
top
attribute of the Window
object is
now defined.
a
element now allows nested flow content, but not
nested interactive content.
header
element means to
document summaries and table of contents.
canvas
element.
autosubmit
attribute has been removed from the
menu
element.
outerHTML
and
insertAdjacentHTML()
has been added.
xml:lang
is now allowed in HTML when lang
is
also specified and they have the same value. In XML lang
is
allowed if xml:lang
is also specified and they have the same
value.
frameElement
attribute of the Window
object is now defined.
alt
attribute is omitted a title
attribute, an enclosing figure
element with a
legend
element descendant, or an enclosing section with an
associated heading must be present.
irrelevant
attribute has been renamed to
hidden
.
definitionURL
attribute of MathML is now properly
supported. Previously it would have ended up being all lowercase during
parsing.
datatemplate
, rule
and nest
elements).
loop
attribute.
load()
method on media elements has been redefined as
asynchronous. It also tries out files in turn now rather than just
looking at the type
attribute of the source
element.
canPlayType()
has been added to the
media elements.
totalBytes
and bufferedBytes
attributes
have been removed from the media elements.
Location
object gained a resolveURL()
method.
q
element has changed again. Punctuation is to be
provided by the user agent again.
unload
and beforeunload
events are now
defined.
headers
attribute pointing to a td
or
th
element, but authors are required to only let them point
to th
elements.
http-equiv
values.
meta
element has a charset
attribute it must occur within the first 512 bytes.
StorageEvent
object now has a
storageArea
attribute.
foreignObject
element.
HTMLDocument
and
Window
objects is now defined.
Window
object gained the locationbar
,
menubar
, personalbar
, scrollbars
,
statusbar
and toolbar
attributes giving
information about the user interface.
document.domain
now relies on the Public Suffix List.
[PSL]
Web Forms 2.0, previously a standalone specification, has been fully integrated into HTML5 since last publication. The following changes were made to the forms chapter:
select
and
datalist
elements through the data
attribute
has been removed.
form
attribute.
dispatchChangeInput()
and
dispatchFormChange()
methods have been removed from the
select
, input
, textarea
, and
button
elements.
inputmode
attribute has been removed.
input
element in the File Upload state no longer
supports the min
and max
attributes.
allow
attribute on input
elements in the
File Upload state is no longer authoritative.
pattern
and accept
attributes for
textarea
have been removed.
submit()
method now just submits, it no longer
ensures the form controls are valid.
input
element in the Range state now defaults to the
middle, rather than the minimum value.
size
attribute on the input
element is
now conforming (rather than deprecated).
object
elements now partake in form submission.
type
attribute of the input
element
gained the values color
and search
.
input
element gained a multiple
attribute which allows for either multiple e-mails or multiple files to
be uploaded depending on the value of the type
attribute.
input
, button
and form
elements now have a novalidate
attribute to indicate that
the form fields should not be required to have valid values upon
submission.
label
element contains an input
it
may still have a for
attribute as long as it points to the
input
element it contains.
input
element now has an indeterminate
IDL attribute.
input
element gained a placeholder
attribute.
ping
attribute have changed.
<meta http-equiv=content-type>
is now a conforming way
to set the character encoding.
canvas
element has been cleaned up. Text
support has been added.
globalStorage
is now restricted to the same-origin policy
and renamed to localStorage
. Related event dispatching has
been clarified.
postMessage()
API changed. Only the origin of the message
is exposed, no longer the URL. It also requires a second argument that
indicates the origin of the target document.
dataTransfer
object now has a types
attribute indicating the type of data
being transferred.
m
element is now called mark
.
figure
element no longer requires a caption.
ol
element has a new reversed
attribute.
queryCommandEnabled()
and related methods.
headers
attribute has been added for td
elements.
table
element has a new createTBody()
method.
data-name
and can
access these through the DOM using dataset[name]
on the element in question.
q
element has changed to require punctuation inside
rather than having the browser render it.
target
attribute can now have the value
_blank
.
showModalDialog
API has been added.
document.domain
API has been defined.
source
element now has a new pixelratio
attribute useful for videos that have some kind encoding error.
bufferedBytes
, totalBytes
and
bufferingThrottled
IDL attributes have been added to the
video
element.
begin
event has been renamed to
loadstart
for consistency with the Progress Events
specification.
charset
attribute has been added to script
.
iframe
element has gained the sandbox
and seamless
attributes which provide sandboxing
functionality.
ruby
, rt
and rp
elements
have been added to support ruby annotation.
showNotification()
method has been added to show
notification messages to the user.
beforeprint
and afterprint
events has been added.
The editor would like to thank Ben Millard, Bruce Lawson, Cameron McCormack, Charles McCathieNevile, Dan Connolly, David Håsäther, Dennis German, Frank Ellermann, Frank Palinkas, Futomi Hatano, Gordon P. Hemsley, Henri Sivonen, James Graham, Jens Meiert, Jeremy Keith, Jürgen Jeka, Krijn Hoetmer, Leif Halvard Silli, Maciej Stachowiak, Marcos Caceres, Mark Pilgrim, Martijn Wargers, Martyn Haigh, Masataka Yakura, Michael Smith, Olivier Gendrin, Øistein E. Andersen, Philip Jägenstedt, Philip Taylor, Randy Peterman, Simon Pieters, Toby Inkster, and Yngve Spjeld Landro for their contributions to this document as well as to all the people who have contributed to HTML5 over the years for improving the Web!