HTML 5.2

W3C Recommendation,


This section summarises substantial changes since the HTML 5.1 Recommendation.

Full details of all changes since 12 January 2016 are available from the commit log of the w3c/html github repository, including various editorial and linking fixes.

New features

Features removed

  • The keygen, menu and menuitem elements.

  • The inputmode attribute for textual input elements, and the dropzone attributes.

  • The showModalDialog method.

  • The Plugin API has been marked as obsolete.

Fixing bugs and matching reality better

  • Stop media resource requests from non-network sources delaying the load event.

  • Remove arbitrary upper limits on refresh rates.

  • Coordinates for ismap no longer include the image’s border in calculation.

  • Update accesskey definition to require a single printable character.

  • Fix the activation algorithm for summary to match reality.

  • Fix the algorithm to determine row and column headers for table.

  • Update the rendering of summary

  • Reflecting a broken URL returns the unparsed value

  • currentScript may return SVGScriptElement.

  • Resetting a textarea resets its dirty value flag.

  • document.open() and document.close() check for XML document.

  • HashChangeEvent URLs are USVString instead of DOMString.

  • Selection members' types are nullable.

  • data: URLs are treated as a separate origin.

  • Sadly, elements that are only focusable because they have a tabindex attribute generally will not fire a click event when activated with a non-pointer device.

  • Navigation for sandboxed contexts

  • Updated allowable role values in line with [html-aria]

The following constructions are now valid HTML:
style within the body.
Multiple main elements in the DOM, so long as only one is visible to the user.
The presentation for the img element.
div as a child of a dl element.
dfn as a descendent of an li element that contains a definition of the term defined.
Headings within legend in a fieldset.
Empty option element as a child of datalist.
Comments containing two consecutive hyphens, or ending with a hyphen, in the HTML syntax.
Remove restrictions on BiDi algorithm section
The following constructions are no longer valid HTML:
role values for a caption element.
Inline blocks, inline tables, or floated and positioned block-level elements as children of a p element.
Content with the HTML4 or XHTML1 strict doctype.

New concepts

Editorial clarifications

  • Browsers should represent punycode addresses as natural unicode text for the email input type.

  • Clarify the concept of last frame time for the seekable IDL attribute

  • Browsers that use the the suggestions source element to filter suggestions should implement substring matching on the label attribute.

  • Users should be able to interact with area elements whether or not they use a pointing device.