HTML

Living Standard — Last Updated 11 August 2026

Index

Index

The following sections only cover conforming elements and features.

Elements

This section is non-normative.

List of elements
Element	Description	Categories	Parents†	Children	Attributes	Interface
`a`	Hyperlink	flow; phrasing*; interactive; palpable	phrasing	transparent*	globals; `href`; `target`; `download`; `ping`; `rel`; `hreflang`; `type`; `referrerpolicy`	`HTMLAnchorElement`
`abbr`	Abbreviation	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`address`	Contact information for a page or `article` element	flow; palpable	flow	flow*	globals	`HTMLElement`
`area`	Hyperlink or dead area on an image map	flow; phrasing	phrasing*	empty	globals; `alt`; `coords`; `shape`; `href`; `target`; `download`; `ping`; `rel`; `referrerpolicy`	`HTMLAreaElement`
`article`	Self-contained syndicatable or reusable composition	flow; sectioning; palpable	flow	flow	globals	`HTMLElement`
`aside`	Sidebar for tangentially related content	flow; sectioning; palpable	flow	flow	globals	`HTMLElement`
`audio`	Audio player	flow; phrasing; embedded; interactive; palpable*	phrasing	`source`; `track`; transparent*	globals; `src`; `crossorigin`; `preload`; `autoplay`; `loading`; `loop`; `muted`; `controls`	`HTMLAudioElement`
`b`	Keywords	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`base`	Base URL and default target navigable for hyperlinks and forms	metadata	`head`	empty	globals; `href`; `target`	`HTMLBaseElement`
`bdi`	Text directionality isolation	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`bdo`	Text directionality formatting	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`blockquote`	A section quoted from another source	flow; palpable	flow	flow	globals; `cite`	`HTMLQuoteElement`
`body`	Document body	none	`html`	flow	globals; `onafterprint`; `onbeforeprint`; `onbeforeunload`; `onhashchange`; `onlanguagechange`; `onmessage`; `onmessageerror`; `onoffline`; `ononline`; `onpageswap`; `onpagehide`; `onpagereveal`; `onpageshow`; `onpopstate`; `onrejectionhandled`; `onstorage`; `onunhandledrejection`; `onunload`	`HTMLBodyElement`
`br`	Line break, e.g. in poem or postal address	flow; phrasing	phrasing	empty	globals	`HTMLBRElement`
`button`	Button control	flow; phrasing; interactive; listed; labelable; submittable; form-associated; palpable	phrasing; `select`*	phrasing*	globals; `command`; `commandfor`; `disabled`; `form`; `formaction`; `formenctype`; `formmethod`; `formnovalidate`; `formtarget`; `name`; `popovertarget`; `popovertargetaction`; `type`; `value`	`HTMLButtonElement`
`canvas`	Scriptable bitmap canvas	flow; phrasing; embedded; palpable	phrasing	transparent	globals; `width`; `height`	`HTMLCanvasElement`
`caption`	Table caption	none	`table`	flow*	globals	`HTMLTableCaptionElement`
`cite`	Title of a work	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`code`	Computer code	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`col`	Table column	none	`colgroup`	empty	globals; `span`	`HTMLTableColElement`
`colgroup`	Group of columns in a table	none	`table`	`col`; `template`	globals; `span`	`HTMLTableColElement`
`data`	Machine-readable equivalent	flow; phrasing; palpable	phrasing	phrasing	globals; `value`	`HTMLDataElement`
`datalist`	Container for options for combo box control	flow; phrasing	phrasing	phrasing; `option`; script-supporting elements*	globals	`HTMLDataListElement`
`dd`	Content for corresponding `dt` element(s)	none	`dl`; `div`*	flow	globals	`HTMLElement`
`del`	A removal from the document	flow; phrasing*; palpable	phrasing	transparent	globals; `cite`; `datetime`	`HTMLModElement`
`details`	Disclosure control for hiding details	flow; interactive; palpable	flow	`summary`*; flow	globals; `name`; `open`	`HTMLDetailsElement`
`dfn`	Defining instance	flow; phrasing; palpable	phrasing	phrasing*	globals	`HTMLElement`
`dialog`	Dialog box or window	flow	flow	flow	globals; `open`	`HTMLDialogElement`
`div`	Generic flow container, or container for name-value groups in `dl` elements	flow; palpable	flow; `dl`; `option`; `optgroup`; `select`	flow*	globals	`HTMLDivElement`
`dl`	Association list consisting of zero or more name-value groups	flow; palpable	flow	`dt`; `dd`; `div`*; script-supporting elements	globals	`HTMLDListElement`
`dt`	Legend for corresponding `dd` element(s)	none	`dl`; `div`*	flow*	globals	`HTMLElement`
`em`	Stress emphasis	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`embed`	Plugin	flow; phrasing; embedded; interactive; palpable	phrasing	empty	globals; `src`; `type`; `width`; `height`; any*	`HTMLEmbedElement`
`fieldset`	Group of form controls	flow; listed; form-associated; palpable	flow	`legend`*; flow	globals; `disabled`; `form`; `name`	`HTMLFieldSetElement`
`figcaption`	Caption for `figure`	none	`figure`	flow	globals	`HTMLElement`
`figure`	Figure with optional caption	flow; palpable	flow	`figcaption`*; flow	globals	`HTMLElement`
`footer`	Footer for a page or section	flow; palpable	flow	flow*	globals	`HTMLElement`
`form`	User-submittable form	flow; palpable	flow	flow*	globals; `accept-charset`; `action`; `autocomplete`; `enctype`; `method`; `name`; `novalidate`; `rel`; `target`	`HTMLFormElement`
`h1`, `h2`, `h3`, `h4`, `h5`, `h6`	Heading	flow; heading; palpable	`legend`; `summary`; flow	phrasing	globals	`HTMLHeadingElement`
`head`	Container for document metadata	none	`html`	metadata content*	globals	`HTMLHeadElement`
`header`	Introductory or navigational aids for a page or section	flow; palpable	flow	flow*	globals	`HTMLElement`
`hgroup`	Heading container	flow; palpable	`legend`; `summary`; flow	`h1`; `h2`; `h3`; `h4`; `h5`; `h6`; `p`; script-supporting elements	globals	`HTMLElement`
`hr`	Thematic break	flow	flow; `select`	empty	globals	`HTMLHRElement`
`html`	Root element	none	none*	`head`; `body`	globals	`HTMLHtmlElement`
`i`	Alternate voice	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`iframe`	Child navigable	flow; phrasing; embedded; interactive; palpable	phrasing	empty	globals; `src`; `srcdoc`; `name`; `sandbox`; `allow`; `allowfullscreen`; `width`; `height`; `referrerpolicy`; `loading`	`HTMLIFrameElement`
`img`	Image	flow; phrasing; embedded; interactive*; form-associated; palpable	phrasing; `picture`	empty	globals; `alt`; `src`; `srcset`; `sizes`; `crossorigin`; `usemap`; `ismap`; `controls`; `width`; `height`; `referrerpolicy`; `decoding`; `loading`; `fetchpriority`	`HTMLImageElement`
`input`	Form control	flow; phrasing; interactive; listed; labelable; submittable; resettable; form-associated; palpable	phrasing	empty	globals; `accept`; `alpha`; `alt`; `autocomplete`; `checked`; `colorspace`; `dirname`; `disabled`; `form`; `formaction`; `formenctype`; `formmethod`; `formnovalidate`; `formtarget`; `height`; `list`; `max`; `maxlength`; `min`; `minlength`; `multiple`; `name`; `pattern`; `placeholder`; `popovertarget`; `popovertargetaction`; `readonly`; `required`; `size`; `src`; `step`; `type`; `value`; `width`	`HTMLInputElement`
`ins`	An addition to the document	flow; phrasing*; palpable	phrasing	transparent	globals; `cite`; `datetime`	`HTMLModElement`
`kbd`	User input	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`label`	Caption for a form control	flow; phrasing; interactive; palpable	phrasing	phrasing*	globals; `for`	`HTMLLabelElement`
`legend`	Caption for `fieldset`	none	`fieldset`; `optgroup`	phrasing*; heading content	globals	`HTMLLegendElement`
`li`	List item	none	`ol`; `ul`; `menu`*	flow	globals; `value`*	`HTMLLIElement`
`link`	Link metadata	metadata; flow; phrasing	`head`; `noscript`; phrasing	empty	globals; `href`; `crossorigin`; `rel`; `as`; `media`; `hreflang`; `type`; `sizes`; `imagesrcset`; `imagesizes`; `referrerpolicy`; `integrity`; `blocking`; `color`; `disabled`; `fetchpriority`	`HTMLLinkElement`
`main`	Container for the dominant contents of the document	flow; palpable	flow*	flow	globals	`HTMLElement`
`map`	Image map	flow; phrasing*; palpable	phrasing	transparent; `area`*	globals; `name`	`HTMLMapElement`
`mark`	Highlight	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
MathML `math`	MathML root	flow; phrasing; embedded; palpable	phrasing	per [MATHML]	per [MATHML]	`Element`
`menu`	Menu of commands	flow; palpable*	flow	`li`; script-supporting elements	globals	`HTMLMenuElement`
`meta`	Text metadata	metadata; flow; phrasing	`head`; `noscript`; phrasing	empty	globals; `name`; `http-equiv`; `content`; `charset`; `media`	`HTMLMetaElement`
`meter`	Gauge	flow; phrasing; labelable; palpable	phrasing	phrasing*	globals; `value`; `min`; `max`; `low`; `high`; `optimum`	`HTMLMeterElement`
`nav`	Section with navigational links	flow; sectioning; palpable	flow	flow	globals	`HTMLElement`
`noscript`	Fallback content for script	metadata; flow; phrasing	`head`; phrasing; `select`; `optgroup`	varies*	globals	`HTMLElement`
`object`	Image, child navigable, or plugin	flow; phrasing; embedded; interactive*; listed; form-associated; palpable	phrasing	transparent	globals; `data`; `type`; `name`; `form`; `width`; `height`	`HTMLObjectElement`
`ol`	Ordered list	flow; palpable*	flow	`li`; script-supporting elements	globals; `reversed`; `start`; `type`	`HTMLOListElement`
`optgroup`	Group of options in a list box	none	`select`; `div`*	`option`; script-supporting elements; `noscript`; `div`; `legend`*	globals; `disabled`; `label`	`HTMLOptGroupElement`
`option`	Option in a list box or combo box control	none	`select`; `datalist`; `optgroup`; `div`*	text; `div`; phrasing*	globals; `disabled`; `label`; `selected`; `value`	`HTMLOptionElement`
`output`	Calculated output value	flow; phrasing; listed; labelable; resettable; form-associated; palpable	phrasing	phrasing	globals; `for`; `form`; `name`	`HTMLOutputElement`
`p`	Paragraph	flow; palpable	flow	phrasing	globals	`HTMLParagraphElement`
`picture`	Image	flow; phrasing; embedded; palpable	phrasing	`source`*; one `img`; script-supporting elements	globals	`HTMLPictureElement`
`pre`	Block of preformatted text	flow; palpable	flow	phrasing	globals	`HTMLPreElement`
`progress`	Progress bar	flow; phrasing; labelable; palpable	phrasing	phrasing*	globals; `value`; `max`	`HTMLProgressElement`
`q`	Quotation	flow; phrasing; palpable	phrasing	phrasing	globals; `cite`	`HTMLQuoteElement`
`rp`	Parenthesis for ruby annotation text	none	`ruby`	text	globals	`HTMLElement`
`rt`	Ruby annotation text	none	`ruby`	phrasing	globals	`HTMLElement`
`ruby`	Ruby annotation(s)	flow; phrasing; palpable	phrasing	phrasing; `rt`; `rp`*	globals	`HTMLElement`
`s`	Inaccurate text	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`samp`	Computer output	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`script`	Embedded script	metadata; flow; phrasing; script-supporting	`head`; phrasing; script-supporting	script, data, or script documentation*	globals; `src`; `type`; `nomodule`; `async`; `defer`; `crossorigin`; `integrity`; `referrerpolicy`; `blocking`; `fetchpriority`	`HTMLScriptElement`
`search`	Container for search controls	flow; palpable	flow	flow	globals	`HTMLElement`
`section`	Generic document or application section	flow; sectioning; palpable	flow	flow	globals	`HTMLElement`
`select`	List box control	flow; phrasing; interactive; listed; labelable; submittable; resettable; form-associated; palpable	phrasing	`option`; `optgroup`; `hr`; script-supporting elements; `noscript`; `div`; `button`*	globals; `autocomplete`; `disabled`; `form`; `multiple`; `name`; `required`; `size`	`HTMLSelectElement`
`selectedcontent`	Mirrors content from an `option`	none	`button`	empty	globals	`HTMLSelectedContentElement`
`slot`	Shadow tree slot	flow; phrasing	phrasing	transparent	globals; `name`	`HTMLSlotElement`
`small`	Side comment	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`source`	Image source for `img` or media source for `video` or `audio`	none	`picture`; `video`; `audio`	empty	globals; `type`; `media`; `src`; `srcset`; `sizes`; `width`; `height`	`HTMLSourceElement`
`span`	Generic phrasing container	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLSpanElement`
`strong`	Importance	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`style`	Embedded styling information	metadata	`head`; `noscript`*	text*	globals; `media`; `blocking`	`HTMLStyleElement`
`sub`	Subscript	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`summary`	Caption for `details`	none	`details`	phrasing; heading content	globals	`HTMLElement`
`sup`	Superscript	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
SVG `svg`	SVG root	flow; phrasing; embedded; palpable	phrasing	per [SVG]	per [SVG]	`SVGSVGElement`
`table`	Table	flow; palpable	flow	`caption`; `colgroup`; `thead`; `tbody`; `tfoot`; `tr`; script-supporting elements	globals	`HTMLTableElement`
`tbody`	Group of rows in a table	none	`table`	`tr`; script-supporting elements	globals	`HTMLTableSectionElement`
`td`	Table cell	none	`tr`	flow	globals; `colspan`; `rowspan`; `headers`	`HTMLTableCellElement`
`template`	Template	metadata; flow; phrasing; script-supporting	metadata; phrasing; script-supporting; `colgroup`*	empty	globals; `shadowrootmode`; `shadowrootdelegatesfocus`; `shadowrootslotassignment`; `shadowrootclonable`; `shadowrootserializable`; `shadowrootcustomelementregistry`	`HTMLTemplateElement`
`textarea`	Multiline text controls	flow; phrasing; interactive; listed; labelable; submittable; resettable; form-associated; palpable	phrasing	text	globals; `autocomplete`; `cols`; `dirname`; `disabled`; `form`; `maxlength`; `minlength`; `name`; `placeholder`; `readonly`; `required`; `rows`; `wrap`	`HTMLTextAreaElement`
`tfoot`	Group of footer rows in a table	none	`table`	`tr`; script-supporting elements	globals	`HTMLTableSectionElement`
`th`	Table header cell	interactive*	`tr`	flow*	globals; `colspan`; `rowspan`; `headers`; `scope`; `abbr`	`HTMLTableCellElement`
`thead`	Group of heading rows in a table	none	`table`	`tr`; script-supporting elements	globals	`HTMLTableSectionElement`
`time`	Machine-readable equivalent of date- or time-related data	flow; phrasing; palpable	phrasing	phrasing	globals; `datetime`	`HTMLTimeElement`
`title`	Document title	metadata	`head`	text*	globals	`HTMLTitleElement`
`tr`	Table row	none	`table`; `thead`; `tbody`; `tfoot`	`th`*; `td`; script-supporting elements	globals	`HTMLTableRowElement`
`track`	Timed text track	none	`audio`; `video`	empty	globals; `default`; `kind`; `label`; `src`; `srclang`	`HTMLTrackElement`
`u`	Unarticulated annotation	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`ul`	List	flow; palpable*	flow	`li`; script-supporting elements	globals	`HTMLUListElement`
`var`	Variable	flow; phrasing; palpable	phrasing	phrasing	globals	`HTMLElement`
`video`	Video player	flow; phrasing; embedded; interactive; palpable	phrasing	`source`; `track`; transparent*	globals; `src`; `crossorigin`; `poster`; `preload`; `autoplay`; `playsinline`; `loading`; `loop`; `muted`; `controls`; `width`; `height`	`HTMLVideoElement`
`wbr`	Line breaking opportunity	flow; phrasing	phrasing	empty	globals	`HTMLElement`
autonomous custom elements	Author-defined elements	flow; phrasing; palpable	flow; phrasing	transparent	globals; any, as decided by the element's author	Supplied by the element's author (inherits from `HTMLElement`)

An asterisk (*) in a cell indicates that the actual rules are more complicated than indicated in the table above.

† Categories in the "Parents" column refer to parents that list the given categories in their content model, not to elements that themselves are in those categories. For example, the a element's "Parents" column says "phrasing", so any element whose content model contains the "phrasing" category could be a parent of an a element. Since the "flow" category includes all the "phrasing" elements, that means the th element could be a parent to an a element.

Element content categories

This section is non-normative.

List of element content categories
Category	Elements	Elements with exceptions
Metadata content	`base`; `link`; `meta`; `noscript`; `script`; `style`; `template`; `title`	—
Flow content	`a`; `abbr`; `address`; `article`; `aside`; `audio`; `b`; `bdi`; `bdo`; `blockquote`; `br`; `button`; `canvas`; `cite`; `code`; `data`; `datalist`; `del`; `details`; `dfn`; `dialog`; `div`; `dl`; `em`; `embed`; `fieldset`; `figure`; `footer`; `form`; `h1`; `h2`; `h3`; `h4`; `h5`; `h6`; `header`; `hgroup`; `hr`; `i`; `iframe`; `img`; `input`; `ins`; `kbd`; `label`; `map`; `mark`; MathML `math`; `menu`; `meter`; `nav`; `noscript`; `object`; `ol`; `output`; `p`; `picture`; `pre`; `progress`; `q`; `ruby`; `s`; `samp`; `script`; `search`; `section`; `select`; `slot`; `small`; `span`; `strong`; `sub`; `sup`; SVG `svg`; `table`; `template`; `textarea`; `time`; `u`; `ul`; `var`; `video`; `wbr`; autonomous custom elements; Text	`area` (if it is a descendant of a `map` element); `link` (if it is allowed in the body); `main` (if it is a hierarchically correct `main` element); `meta` (if the `itemprop` attribute is present)
Sectioning content	`article`; `aside`; `nav`; `section`	—
Heading content	`h1`; `h2`; `h3`; `h4`; `h5`; `h6`; `hgroup`	—
Phrasing content	`a`; `abbr`; `audio`; `b`; `bdi`; `bdo`; `br`; `button`; `canvas`; `cite`; `code`; `data`; `datalist`; `del`; `dfn`; `em`; `embed`; `i`; `iframe`; `img`; `input`; `ins`; `kbd`; `label`; `map`; `mark`; MathML `math`; `meter`; `noscript`; `object`; `output`; `picture`; `progress`; `q`; `ruby`; `s`; `samp`; `script`; `select`; `selectedcontent`; `slot`; `small`; `span`; `strong`; `sub`; `sup`; SVG `svg`; `template`; `textarea`; `time`; `u`; `var`; `video`; `wbr`; autonomous custom elements; Text	`area` (if it is a descendant of a `map` element); `link` (if it is allowed in the body); `meta` (if the `itemprop` attribute is present)
Embedded content	`audio`; `canvas`; `embed`; `iframe`; `img`; MathML `math`; `object`; `picture`; SVG `svg`; `video`	—
Interactive content	`button`; `details`; `embed`; `iframe`; `label`; `select`; `textarea`	`a` (if the `href` attribute is present); `audio` (if the `controls` attribute is present); `img` (if the `usemap` or `controls` attribute is present); `input` (if the `type` attribute is not in the Hidden state); `video` (if the `controls` attribute is present)
Form-associated elements	`button`; `fieldset`; `input`; `label`; `object`; `output`; `select`; `textarea`; `img`; form-associated custom elements	—
Listed elements	`button`; `fieldset`; `input`; `object`; `output`; `select`; `textarea`; form-associated custom elements	—
Submittable elements	`button`; `input`; `select`; `textarea`; form-associated custom elements	—
Resettable elements	`input`; `output`; `select`; `textarea`; form-associated custom elements	—
Autocapitalize-and-autocorrect inheriting elements	`button`; `fieldset`; `input`; `output`; `select`; `textarea`	—
Labelable elements	`button`; `input`; `meter`; `output`; `progress`; `select`; `textarea`; form-associated custom elements	—
Palpable content	`a`; `abbr`; `address`; `article`; `aside`; `b`; `bdi`; `bdo`; `blockquote`; `button`; `canvas`; `cite`; `code`; `data`; `del`; `details`; `dfn`; `div`; `em`; `embed`; `fieldset`; `figure`; `footer`; `form`; `h1`; `h2`; `h3`; `h4`; `h5`; `h6`; `header`; `hgroup`; `i`; `iframe`; `img`; `ins`; `kbd`; `label`; `main`; `map`; `mark`; MathML `math`; `meter`; `nav`; `object`; `output`; `p`; `picture`; `pre`; `progress`; `q`; `ruby`; `s`; `samp`; `search`; `section`; `select`; `small`; `span`; `strong`; `sub`; `sup`; SVG `svg`; `table`; `textarea`; `time`; `u`; `var`; `video`; autonomous custom elements	`audio` (if the `controls` attribute is present); `dl` (if the element's children include at least one name-value group); `input` (if the `type` attribute is not in the Hidden state); `menu` (if the element's children include at least one `li` element); `ol` (if the element's children include at least one `li` element); `ul` (if the element's children include at least one `li` element); Text that is not inter-element whitespace
Script-supporting elements	`script`; `template`	—

Attributes

This section is non-normative.

List of attributes (excluding event handler content attributes)
Attribute	Element(s)	Description	Value
`abbr`	`th`	Alternative label to use for the header cell when referencing the cell in other contexts	Text*
`accept`	`input`	Hint for expected file type in file upload controls	Set of comma-separated tokens* consisting of valid MIME type strings with no parameters or `audio/`, `video/`, or `image/*`
`accept-charset`	`form`	Character encodings to use for form submission	ASCII case-insensitive match for "`UTF-8`"
`accesskey`	HTML elements	Keyboard shortcut to activate or focus element	Ordered set of unique space-separated tokens, none of which are identical to another, each consisting of one code point in length
`action`	`form`	URL to use for form submission	Valid non-empty URL potentially surrounded by spaces
`allow`	`iframe`	Permissions policy to be applied to the `iframe`'s contents	Serialized permissions policy
`allowfullscreen`	`iframe`	Whether to allow the `iframe`'s contents to use `requestFullscreen()`	Boolean attribute
`alpha`	`input`	Allow the color's alpha component to be set	Boolean attribute
`alt`	`area`; `img`; `input`	Replacement text for use when images are not available	Text*
`as`	`link`	Destination for a preload request (for `rel`="`preload`" and `rel`="`modulepreload`")	Preload destination, for `rel`="`preload`"; module preload destination, for `rel`="`modulepreload`"
`async`	`script`	Execute script when available, without blocking while fetching	Boolean attribute
`autocapitalize`	HTML elements	Recommended autocapitalization behavior (for supported input methods)	"`on`"; "`off`"; "`none`"; "`sentences`"; "`words`"; "`characters`"
`autocomplete`	`form`	Default setting for autofill feature for controls in the form	"`on`"; "`off`"
`autocomplete`	`input`; `select`; `textarea`	Hint for form autofill feature	Autofill field name and related tokens*
`autocorrect`	HTML elements	Recommended autocorrection behavior (for supported input methods)	"`on`"; "`off`"; the empty string
`autofocus`	HTML elements	Automatically focus the element when the page is loaded	Boolean attribute
`autoplay`	`audio`; `video`	Hint that the media resource can be started automatically when the page is loaded	Boolean attribute
`blocking`	`link`; `script`; `style`	Whether the element is potentially render-blocking	Unordered set of unique space-separated tokens*
`charset`	`meta`	Character encoding declaration	"`utf-8`"
`checked`	`input`	Whether the control is checked	Boolean attribute
`cite`	`blockquote`; `del`; `ins`; `q`	Link to the source of the quotation or more information about the edit	Valid URL potentially surrounded by spaces
`class`	HTML elements	Classes to which the element belongs	Set of space-separated tokens
`closedby`	`dialog`	Which user actions will close the dialog	"`any`"; "`closerequest`"; "`none`";
`color`	`link`	Color to use when customizing a site's icon (for `rel`="`mask-icon`")	CSS <color>
`colorspace`	`input`	The color space of the serialized color	"`limited-srgb`"; "`display-p3`"
`cols`	`textarea`	Maximum number of characters per line	Valid non-negative integer greater than zero
`colspan`	`td`; `th`	Number of columns that the cell is to span	Valid non-negative integer greater than zero
`command`	`button`	Indicates to the targeted element which action to take.	"`toggle-popover`"; "`show-popover`"; "`hide-popover`"; "`close`"; "`request-close`"; "`show-modal`"; a custom command keyword
`commandfor`	`button`	Targets another element to be invoked.	ID*
`content`	`meta`	Value of the element	Text*
`contenteditable`	HTML elements	Whether the element is editable	"`true`"; "`false`"; "`plaintext-only`"; the empty string
`controls`	`audio`; `video` `img`;	Show user agent controls	Boolean attribute
`coords`	`area`	Coordinates for the shape to be created in an image map	Valid list of floating-point numbers*
`crossorigin`	`audio`; `img`; `link`; `script`; `video`	How the element handles crossorigin requests	"`anonymous`"; "`use-credentials`"; the empty string
`data`	`object`	Address of the resource	Valid non-empty URL potentially surrounded by spaces
`datetime`	`del`; `ins`	Date and (optionally) time of the change	Valid date string with optional time
`datetime`	`time`	Machine-readable value	Valid month string, valid date string, valid yearless date string, valid time string, valid local date and time string, valid time-zone offset string, valid global date and time string, valid week string, valid non-negative integer, or valid duration string
`decoding`	`img`	Decoding hint to use when processing this image for presentation	"`sync`"; "`async`"; "`auto`"
`default`	`track`	Enable the track if no other text track is more suitable	Boolean attribute
`defer`	`script`	Defer script execution	Boolean attribute
`dir`	HTML elements	The text directionality of the element	"`ltr`"; "`rtl`"; "`auto`"
`dir`	`bdo`	The text directionality of the element	"`ltr`"; "`rtl`"
`dirname`	`input`; `textarea`	Name of form control to use for sending the element's directionality in form submission	Text*
`disabled`	`button`; `input`; `optgroup`; `option`; `select`; `textarea`; form-associated custom elements	Whether the form control is disabled	Boolean attribute
`disabled`	`fieldset`	Whether the descendant form controls, except any inside `legend`, are disabled	Boolean attribute
`disabled`	`link`	Whether the link is disabled	Boolean attribute
`download`	`a`; `area`	Whether to download the resource instead of navigating to it, and its filename if so	Text
`draggable`	HTML elements	Whether the element is draggable	"`true`"; "`false`"
`enctype`	`form`	Entry list encoding type to use for form submission	"`application/x-www-form-urlencoded`"; "`multipart/form-data`"; "`text/plain`"
`enterkeyhint`	HTML elements	Hint for selecting an enter key action	"`enter`"; "`done`"; "`go`"; "`next`"; "`previous`"; "`search`"; "`send`"
`fetchpriority`	`img`; `link`; `script`	Sets the priority for fetches initiated by the element	"`auto`"; "`high`"; "`low`"
`for`	`label`	Associate the label with form control	ID*
`for`	`output`	Specifies controls from which the output was calculated	Unordered set of unique space-separated tokens consisting of IDs*
`form`	`button`; `fieldset`; `input`; `object`; `output`; `select`; `textarea`; form-associated custom elements	Associates the element with a `form` element	ID*
`formaction`	`button`; `input`	URL to use for form submission	Valid non-empty URL potentially surrounded by spaces
`formenctype`	`button`; `input`	Entry list encoding type to use for form submission	"`application/x-www-form-urlencoded`"; "`multipart/form-data`"; "`text/plain`"
`formmethod`	`button`; `input`	Variant to use for form submission	"`get`"; "`post`"; "`dialog`"
`formnovalidate`	`button`; `input`	Bypass form control validation for form submission	Boolean attribute
`formtarget`	`button`; `input`	Navigable for form submission	Valid navigable target name or keyword
`headers`	`td`; `th`	The header cells for this cell	Unordered set of unique space-separated tokens consisting of IDs*
`headingoffset`	HTML elements	Offsets heading levels for descendants	Valid non-negative integer between 0 and 8
`headingreset`	HTML elements	Prevents a heading offset computation from traversing beyond the element with the attribute	Boolean attribute
`height`	`canvas`; `embed`; `iframe`; `img`; `input`; `object`; `source` (in `picture`); `video`	Vertical dimension	Valid non-negative integer
`hidden`	HTML elements	Whether the element is relevant	"`until-found`"; "`hidden`"; the empty string
`high`	`meter`	Low limit of high range	Valid floating-point number*
`href`	`a`; `area`	Address of the hyperlink	Valid URL potentially surrounded by spaces
`href`	`link`	Address of the hyperlink	Valid non-empty URL potentially surrounded by spaces
`href`	`base`	Document base URL	Valid URL potentially surrounded by spaces
`hreflang`	`a`; `link`	Language of the linked resource	Valid BCP 47 language tag
`http-equiv`	`meta`	Pragma directive	"`content-type`"; "`default-style`"; "`refresh`"; "`x-ua-compatible`"; "`content-security-policy`"
`id`	HTML elements	The element's ID	Text*
`imagesizes`	`link`	Image sizes for different page layouts (for `rel`="`preload`")	Valid source size list
`imagesrcset`	`link`	Images to use in different situations, e.g., high-resolution displays, small monitors, etc. (for `rel`="`preload`")	Comma-separated list of image candidate strings
`inert`	HTML elements	Whether the element is inert.	Boolean attribute
`inputmode`	HTML elements	Hint for selecting an input modality	"`none`"; "`text`"; "`tel`"; "`email`"; "`url`"; "`numeric`"; "`decimal`"; "`search`"
`integrity`	`link`; `script`	Integrity metadata used in Subresource Integrity checks [SRI]	Text
`is`	HTML elements	Creates a customized built-in element	Valid custom element name of a defined customized built-in element
`ismap`	`img`	Whether the image is a server-side image map	Boolean attribute
`itemid`	HTML elements	Global identifier for a microdata item	Valid URL potentially surrounded by spaces
`itemprop`	HTML elements	Property names of a microdata item	Unordered set of unique space-separated tokens consisting of valid absolute URLs, defined property names, or text*
`itemref`	HTML elements	Referenced elements	Unordered set of unique space-separated tokens consisting of IDs*
`itemscope`	HTML elements	Introduces a microdata item	Boolean attribute
`itemtype`	HTML elements	Item types of a microdata item	Unordered set of unique space-separated tokens consisting of valid absolute URLs*
`kind`	`track`	The type of text track	"`subtitles`"; "`captions`"; "`descriptions`"; "`chapters`"; "`metadata`"
`label`	`optgroup`; `option`; `track`	User-visible label	Text
`lang`	HTML elements	Language of the element	Valid BCP 47 language tag or the empty string
`list`	`input`	List of autocomplete options	ID*
`loading`	`iframe`; `img`; `audio`; `video`	Used when determining loading deferral	"`lazy`"; "`eager`"
`loop`	`audio`; `video`	Whether to loop the media resource	Boolean attribute
`low`	`meter`	High limit of low range	Valid floating-point number*
`ma`