Implemented and widely deployed
Tests: 0
Demos: 0
Latest Internet Explorer beta: not applicable
Latest Firefox trunk nightly build: not applicable
Latest WebKit or Chromium trunk build: not applicable
Latest Opera beta or preview build: not applicable
JavaScript libraries, plugins, etc: not applicable
The following sections only cover conforming elements and features.
Last call for comments
Tests: 0
Demos: 0
Latest Internet Explorer beta: no support whatsoever
Latest Firefox trunk nightly build: no support whatsoever
Latest WebKit or Chromium trunk build: no support whatsoever
Latest Opera beta or preview build: no support whatsoever
JavaScript libraries, plugins, etc: no support whatsoever
This section is non-normative.
An asterisk (*) in a cell indicates that the actual rules are more complicated than indicated in the table above.
This section is non-normative.
This section is non-normative.
| Attribute | Element(s) | Description | Value | 
|---|---|---|---|
| accept | input | Hint for expected file type in file upload controls | Set of comma-separated tokens* consisting of valid MIME types with no parameters or audio/*,video/*, orimage/* | 
| accept-charset | form | Character encodings to use for form submission | Ordered set of unique space-separated tokens consisting of preferred MIME names of ASCII-compatible character encodings* | 
| accesskey | HTML elements | Keyboard shortcut to activate or focus element | Ordered set of unique space-separated tokens consisting of one Unicode code point in length | 
| action | form | URL to use for form submission | Valid URL potentially surrounded by spaces | 
| alt | area;img;input | Replacement text for use when images are not available | Text* | 
| async | script | Execute script asynchronously | Boolean attribute | 
| autocomplete | form;input | Prevent the user agent from providing autocompletions for the form control(s) | " on"; "off" | 
| autofocus | button;input;keygen;select;textarea | Automatically focus the form control 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 | 
| challenge | keygen | String to package with the generated and signed public key | Text | 
| charset | meta | Character encoding declaration | Preferred MIME name of an encoding* | 
| charset | script | Character encoding of the external script resource | Preferred MIME name of an encoding* | 
| checked | command;input | Whether the command or 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 | Unordered set of unique space-separated tokens | 
| 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 | 
| content | meta | Value of the element | Text* | 
| contenteditable | HTML elements | Whether the element is editable | " true"; "false" | 
| contextmenu | HTML elements | The element's context menu | ID* | 
| controls | audio;video | Show user agent controls | Boolean attribute | 
| coords | area | Coordinates for the shape to be created in an image map | Valid list of integers* | 
| 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 | Value of the element | Valid date or time string* | 
| defer | script | Defer script execution | Boolean attribute | 
| dir | HTML elements | The text directionality of the element | " ltr"; "rtl" | 
| disabled | button;command;fieldset;input;keygen;optgroup;option;select;textarea | Whether the form control is disabled | Boolean attribute | 
| draggable | HTML elements | Whether the element is draggable | " true"; "false" | 
| enctype | form | Form data set encoding type to use for form submission | " application/x-www-form-urlencoded"; "multipart/form-data"; "text/plain" | 
| 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;keygen;label;meter;object;output;progress;select;textarea | Associates the control with a formelement | ID* | 
| formaction | button;input | URL to use for form submission | Valid URL potentially surrounded by spaces | 
| formenctype | button;input | Form data set encoding type to use for form submission | " application/x-www-form-urlencoded"; "multipart/form-data"; "text/plain" | 
| formmethod | button;input | HTTP method to use for form submission | " GET"; "POST"; "PUT"; "DELETE" | 
| formnovalidate | button;input | Bypass form control validation for form submission | Boolean attribute | 
| formtarget | button;input | Browsing context for form submission | Valid browsing context name or keyword | 
| headers | td;th | The header cells for this cell | Unordered set of unique space-separated tokens consisting of IDs* | 
| height | canvas;embed;iframe;img;input;object;video | Vertical dimension | Valid non-negative integer | 
| hidden | HTML elements | Whether the element is relevant | Boolean attribute | 
| 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;area;link | Language of the linked resource | Valid BCP 47 language tag | 
| http-equiv | meta | Pragma directive | Text* | 
| icon | command | Icon for the command | Valid non-empty URL potentially surrounded by spaces | 
| id | HTML elements | The element's ID | Text* | 
| 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 type of a microdata item | Valid absolute URL* | 
| keytype | keygen | The type of cryptographic key to generate | Text* | 
| kind | track | The type of timed track | " subtitles";
          "captions";
          "descriptions";
          "chapters";
          "metadata" | 
| label | command;menu;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* | 
| loop | audio;video | Whether to loop the media resource | Boolean attribute | 
| low | meter | High limit of low range | Valid floating point number* | 
| manifest | html | Application cache manifest | Valid non-empty URL potentially surrounded by spaces | 
| max | input | Maximum value | varies* | 
| max | meter;progress | Upper bound of range | Valid floating point number* | 
| maxlength | input;textarea | Maximum length of value | Valid non-negative integer | 
| media | a;area;link;source;style | Applicable media | Valid media query | 
| method | form | HTTP method to use for form submission | " GET"; "POST"; "PUT"; "DELETE" | 
| min | input | Minimum value | varies* | 
| min | meter | Lower bound of range | Valid floating point number* | 
| multiple | input;select | Whether to allow multiple values | Boolean attribute | 
| name | button;fieldset;input;keygen;output;select;textarea | Name of form control to use for form submission and in the form.elementsAPI | Text* | 
| name | form | Name of form to use in the document.formsAPI | Text* | 
| name | iframe;object | Name of nested browsing context | Valid browsing context name or keyword | 
| name | map | Name of image map to reference from the usemapattribute | Text* | 
| name | meta | Metadata name | Text* | 
| name | param | Name of parameter | Text | 
| novalidate | form | Bypass form control validation for form submission | Boolean attribute | 
| open | details | Whether the details are visible | Boolean attribute | 
| optimum | meter | Optimum value in gauge | Valid floating point number* | 
| pattern | input | Pattern to be matched by the form control's value | Regular expression matching the JavaScript Pattern production | 
| ping | a;area | URLs to ping | Set of space-separated tokens consisting of valid non-empty URLs | 
| placeholder | input;textarea | User-visible label to be placed within the form control | Text* | 
| poster | video | Poster frame to show prior to video playback | Valid non-empty URL potentially surrounded by spaces | 
| preload | audio;video | Hints how much buffering the media resource will likely need | " none";
          "metadata";
          "auto" | 
| pubdate | time | Whether the element's value represents a publication time for the nearest articleorbody | Boolean attribute | 
| radiogroup | command | Name of group of commands to treat as a radio button group | Text | 
| readonly | input;textarea | Whether to allow the value to be edited by the user | Boolean attribute | 
| rel | a;area;link | Relationship between the document containing the hyperlink and the destination resource | Set of space-separated tokens* | 
| required | input;select;textarea | Whether the control is required for form submission | Boolean attribute | 
| reversed | ol | Number the list backwards | Boolean attribute | 
| rows | textarea | Number of lines to show | Valid non-negative integer greater than zero | 
| rowspan | td;th | Number of rows that the cell is to span | Valid non-negative integer | 
| sandbox | iframe | Security rules for nested content | Unordered set of unique space-separated tokens consisting of
          " allow-same-origin",
          "allow-forms", and
          "allow-scripts" | 
| spellcheck | HTML elements | Whether the element is to have its spelling and grammar checked | " true"; "false" | 
| scope | th | Specifies which cells the header cell applies to | " row";
          "col";
          "rowgroup";
          "colgroup" | 
| scoped | style | Whether the styles apply to the entire document or just the parent subtree | Boolean attribute | 
| seamless | iframe | Whether to apply the document's styles to the nested content | Boolean attribute | 
| selected | option | Whether the option is selected by default | Boolean attribute | 
| shape | area | The kind of shape to be created in an image map | " circle";
          "default";
          "poly";
          "rect" | 
| size | input;select | Size of the control | Valid non-negative integer greater than zero | 
| sizes | link | Sizes of the icons (for rel="icon") | Unordered set of unique space-separated tokens consisting of sizes* | 
| span | col;colgroup | Number of columns spanned by the element | Valid non-negative integer greater than zero | 
| src | audio;embed;iframe;img;input;script;source;track;video | Address of the resource | Valid non-empty URL potentially surrounded by spaces | 
| srcdoc | iframe | A document to render in the iframe | The source of an iframesrcdocdocument* | 
| srclang | track | Language of the timed track | Valid BCP 47 language tag | 
| start | ol | Ordinal value of the first item | Valid integer | 
| step | input | Granularity to be matched by the form control's value | Valid floating point number greater than zero, or " any" | 
| style | HTML elements | Presentational and formatting instructions | CSS declarations* | 
| summary | table | Explanatory text for complex tables for users of screen readers | Text* | 
| tabindex | HTML elements | Whether the element is focusable, and the relative order of the element for the purposes of sequential focus navigation | Valid integer | 
| target | a;area | Browsing context for hyperlink navigation | Valid browsing context name or keyword | 
| target | base | Default browsing context for hyperlink navigation and form submission | Valid browsing context name or keyword | 
| target | form | Browsing context for form submission | Valid browsing context name or keyword | 
| title | HTML elements | Advisory information for the element | Text | 
| title | abbr;dfn | Full term or expansion of abbreviation | Text | 
| title | command | Hint describing the command | Text | 
| title | link | Title of the link | Text | 
| title | link;style | Alternative style sheet set name | Text | 
| type | a;area;link | Hint for the type of the referenced resource | Valid MIME type | 
| type | button | Type of button | " submit";
          "reset";
          "button" | 
| type | button;input | Type of form control | inputtype keyword | 
| type | command | Type of command | " command";
          "checkbox";
          "radio" | 
| type | embed;object;script;source;style | Type of embedded resource | Valid MIME type | 
| type | menu | Type of menu | " context"; "toolbar" | 
| usemap | img;object | Name of image map to use | Valid hash-name reference* | 
| value | button;option | Value to be used for form submission | Text | 
| value | input | Value of the form control | varies* | 
| value | li | Ordinal value of the list item | Valid integer | 
| value | meter;progress | Current value of the element | Valid floating point number | 
| value | param | Value of parameter | Text | 
| width | canvas;embed;iframe;img;input;object;video | Horizontal dimension | Valid non-negative integer | 
| wrap | textarea | How the value of the form control is to be wrapped for form submission | " soft";
          "hard" | 
An asterisk (*) in a cell indicates that the actual rules are more complicated than indicated in the table above.
Last call for comments
Tests: 1 — View...
Demos: 0
Latest Internet Explorer beta: no support whatsoever
Latest Firefox trunk nightly build: no support whatsoever
Latest WebKit or Chromium trunk build: no support whatsoever
Latest Opera beta or preview build: no support whatsoever
JavaScript libraries, plugins, etc: no support whatsoever
This section is non-normative.
Last call for comments
Tests: 0
Demos: 0
Latest Internet Explorer beta: no support whatsoever
Latest Firefox trunk nightly build: no support whatsoever
Latest WebKit or Chromium trunk build: no support whatsoever
Latest Opera beta or preview build: no support whatsoever
JavaScript libraries, plugins, etc: no support whatsoever
This section is non-normative.
| Event | Interface | Description | 
|---|---|---|
| DOMActivate | Event | Fired at an element before its activation behavior is run | 
| DOMContentLoaded | Event | Fired at the Documentonce it and its scripts have loaded, without waiting for other subresources | 
| abort | Event | Fired at the Windowwhen the download was aborted by the user | 
| afterprint | Event | Fired at the Windowafter printing | 
| beforeprint | Event | Fired at the Windowbefore printing | 
| beforeunload | BeforeUnloadEvent | Fired at the Windowwhen the page is about to be unloaded, in case the page would like to show a warning prompt | 
| blur | Event | Fired at nodes losing focus | 
| change | Event | Fired at controls when the user commits a value change | 
| contextmenu | Event | Fired at elements when the user requests their context menu | 
| error | Event | Fired at elements when network and script errors occur | 
| focus | Event | Fired at nodes gaining focus | 
| formchange | Event | Fired at form controls when the user commits a value change to a control on the form | 
| forminput | Event | Fired at form controls when the user changes the value of a control on the form | 
| hashchange | HashChangeEvent | Fired at the Windowwhen the fragment identifier part of the document's current address changes | 
| input | Event | Fired at controls when the user changes the value | 
| invalid | Event | Fired at controls during form validation if they do not satisfy their constraints | 
| load | Event | Fired at the Windowwhen the document has finished loading; fired at an element containing a resource (e.g.img,embed) when its resource has finished loading | 
| message | MessageEvent | Fired at an object when the object receives a message | 
| offline | Event | Fired at the Windowwhen the network connections fails | 
| online | Event | Fired at the Windowwhen the network connections returns | 
| pagehide | PageTransitionEvent | Fired at the Windowwhen the page's entry in the session history stops being the current entry | 
| pageshow | PageTransitionEvent | Fired at the Windowwhen the page's entry in the session history becomes the current entry | 
| popstate | PopStateEvent | Fired at the Windowwhen the user navigates the session history | 
| readystatechange | Event | Fired at the Documentwhen it finishes parsing and again when all its subresources have finished loading | 
| redo | UndoManagerEvent | Fired at the Windowobject when the user goes forward in the undo transaction history | 
| reset | Event | Fired at a formelement when it is reset | 
| show | Event | Fired at a menuelement when it is shown as a context menu | 
| submit | Event | Fired at a formelement when it is submitted | 
| undo | UndoManagerEvent | Fired at the Windowobject when the user goes backward in the undo transaction history | 
| unload | Event | Fired at the Windowobject when the page is going away | 
See also media element events, application cache events, and drag-and-drop events.
Last call for comments
Tests: 0
Demos: 0
Latest Internet Explorer beta: no support whatsoever
Latest Firefox trunk nightly build: no support whatsoever
Latest WebKit or Chromium trunk build: no support whatsoever
Latest Opera beta or preview build: no support whatsoever
JavaScript libraries, plugins, etc: no support whatsoever