Attributes

Attributes modify HTML elements.

attribute-name="attribute-value"

Attributes have a name and a value.

The name is followed by an equal sign = .

The value is enclosed in quotes "" .

<tag-name attribute-name="attribute-value">

Attributes are included in the start tag of HTML elements.

Sample

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<html>
  <head>
    <title>Attributes</title>
  </head>
  <body>
    <p style="color:red">Attributes</p>
    <img alt="Happy Face" src="/assets/jpg/HappyFace.jpg" width="200px">
  </body>
</html>
Name: Value:
style color:red
alt Happy Face
src /assets/jpg/HappyFace.jpg
width 200px

Example

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List

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Attributes may be specific to an HTML element or common to all HTML elements.

 
Specific:
Name: Value: Description:
accept mime-type list Provides the UA with a hint of what file types the server is able to accept
accept-charset character-encoding name list Specifies the character encodings used for form submission
action URI Submission action for the form
alt normal character data Fallback content for the image map
async async | empty Specifies that the script should be executed asynchronously, as soon as it becomes available - HTML5
autocomplete on | off Specifies whether the element represents an input control for which a UA is meant to store the value entered by the user (so that the UA can prefill the form later) - HTML5
autofocus autofocus | empty Specifies that the element represents a control to which a UA is meant to give focus as soon as the document is loaded - HTML5
autoplay autoplay | empty Instructs the UA to automatically begin playback of the audio stream as soon as it can do so without stopping
challenge string Challenge string that is submitted along with the public key
charset character encoding name Specifies a character encoding name - HTML5
charset character encoding name Character encoding of the external script
checked checked | empty Specifies that the element represents a selected control
cite URI URL referencing the original source for the quoted material
cols positive integer Expected maximum number of characters per line of text for the UA to show
colspan positive integer Specifies the number of adjacent columns "spanned" by its td element
content string Specifies the value part of a name/value pair
controls controls | empty Instructs the UA to expose a user interface for controlling playback of the audio stream
coords circle | polygon | rectangle Coordinates for the shape on the image map
data URI Address of the content
datetime date-time Time and date when the text was added/deleted
datetime date or time Specifies the date or time that the element represents
defer defer | empty Specifies that script should be executed after the document has been parsed
disabled disabled | empty Specifies that the element represents a disabled control
enctype application/x-www-form-urlencoded | multipart/form-data | text/plain MIME type with which a UA is meant to associate the form contents for form submission
for IDREF Identifies a form control for which the label is a caption
for IDREFS Identifies one or more elements associated with the calculation whose result this output element represents
form IDREF Identifies a form with which to associate the element - HTML5
formaction URI Form-submission action for the element - HTML5
formenctype application/x-www-form-urlencoded | multipart/form-data | text/plain MIME type with which a UA is meant to associate this element for form submission - HTML5
formmethod get | post | put | delete HTTP method with which a UA is meant to associate this element for form submission - HTML5
formnovalidate formnovalidate | empty Specifies that the element represents a control whose value is not meant to be validated during form submission - HTML5
formtarget browsing-context name or keyword Browsing context or keyword that represents the target of the control - HTML5
headers IDREFS Identifies one or more th elements that apply to its td
height non-negative integer Height of the canvas in CSS pixels
high float Point that marks the lower boundary of the "high" segment of the meter
href URI URL that provides the destination of the hyperlink
href URI Base URL for the document
hreflang language tag Language of the destination of the hyperlink
http-equiv refresh Indicates that the meta element is a pragma directive that specifies either a number of seconds after which to reload the current page, or a number of seconds after which to load a different page in place of the current page, and the URL for the replacement page
icon URI URL for an image that represents the command
ismap ismap | empty Specifies that its img element provides access to a server-side image map
keytype rsa Type of key generated
label string Specifies the label of the element
list IDREF Identifies a datalist with which to associate the element - HTML5
loop loop | empty Instructs the UA to seek back to the start of the audio stream upon reaching the end
low float Point that marks the upper boundary of the "low" segment of the meter
manifest URI Address of the document's application cache manifest (which controls caching of content for offline use) - HTML5
max date-time | local date-time | date | month | time | week | float Expected upper bound for the element's value - HTML5
max float Upper bound of the range
maxlength positive integer Maximum allowed value length of the element
media media query list Media for which the destination of the hyperlink was designed - HTML5
method get | post | put | delete HTTP method with which a UA is meant to associate this element for form submission
min date-time | local date-time | date | month | time | week | float Expected lower bound for the element's value - HTML5
min float Lower bound of the range
multiple multiple | empty Specifies that the element allows multiple values - HTML5
name string Name part of the name/value pair associated with this element for the purposes of form submission
name browsing-context name Valid browsing context name
name name Name by which the map can be referenced
name string Specifies the name part of a name/value pair
name string Name of the parameter
novalidate novalidate | empty Specifies that the element represents a form that is not meant to be validated during form submission - HTML5
onafterprint string Handles the event after printing
onbeforeprint string Handles the event before printing
onbeforeunload string Handles the event when the page is about to be unloaded, in case the page would like to show a warning prompt
onhashchange string Handles the event when the fragment identifier part of the document's current address changes
onmessage string Handles the event when the object receives a message
onoffline string Handles the event when the network connections fails
ononline string Handles the event when the network connections returns
onpagehide string Handles the event when the page's entry in the session history stops being the current entry
onpageshow string Handles the event when the page's entry in the session history becomes the current entry
onpopstate string Handles the event when the user navigates the session history
onredo string Handles the event when the user goes forward in the undo transaction history
onresize string Handles the event when the page is resized
onstorage string Handles the event when storage occurs
onundo string Handles the event when the user goes backward in the undo transaction history
onunload string Handles the event when the page is going away
open open | empty Specifies that the contents of the details element should be shown to the user
optimum float Point that marks the "optimum" position for the meter
pattern pattern Specifies a regular expression against which a UA is meant to check the value of the control represented by its element - HTML5
ping list of URIs List of URLs to notify if a user follows the hyperlink - HTML5
placeholder string Short hint (one word or a short phrase) intended to aid the user when entering data into the control represented by its element - HTML5
poster URI Address of an image file for the UA to show while no video data is available
preload preload | empty Instructs the UA that downloading the entire audio stream optimistically is considered worthwhile
pubdate pubdate | empty Indicates that the date and time given by the element is the publication date and time of the nearest ancestor article element - or, if the element has no ancestor article element, of the document as a whole
radiogroup string Name of the group of commands that will be toggled when the command itself is toggled
readonly readonly | empty Specifies that element represents a control whose value is not meant to be edited
rel tokens List of tokens that specify the relationship between the document containing the hyperlink and the destination indicated by the hyperlink
required required | empty Specifies that the element is a required part of form submission - HTML5
reversed reversed | empty Descending list if present, ascending list if not present - HTML5
rows positive integer Number of lines of text for the UA to show
rowspan non-negative integer Specifies the number of following rows "spanned" by its td element
sandbox sandbox allow list Instructs the UA to enable a set of extra restrictions on any content hosted by the iframe - HTML5
scope row | col | rowgroup | colgroup Specifies what set of cells the th element applies to
scoped scoped | empty Indicates that the specified style information is meant to apply only to the style element's parent element, and that element's child nodes. Otherwise, the specified styles are meant to apply to the entire document - HTML5
seamless seamless | empty Instructs the UA that the iframe element's browsing context is to be rendered in a manner that makes it appear to be part of the containing document (seamlessly included in the parent document) - HTML5
selected selected | empty Specifies that this option is pre-selected
shape circle | polygon | rectangle | default Specifies the shape of the area for the hyperlink on the image map
size positive integer Number of options meant to be shown by the control represented by its element
sizes any | sizes Sizes of icons for visual media - HTML5
span positive integer Number of columns in the group
src URI URL for the audio stream
srcdoc iframe srcdoc Content of the page that the nested browsing context is to contain - HTML5
start integer Ordinal value of the first list item
step any | positive float | positive integer Specifies the value granularity of the element's value - HTML5
summary string Prose description of the structure of the table
target browsing-context name or keyword Name or keyword giving a browsing context for UAs to use when following the hyperlink
target browsing-context name or keyword Browsing context name or keyword for use in following hyperlinks - HTML5
target browsing-context name or keyword Browsing context or keyword that represents the target of the form
type MIME type MIME type of the destination of the hyperlink
type submit | reset | button Specifies that its button element is a button for submitting a form, for resetting a form, or with no additional semantics
type button | checkbox | color | date | datetime | datetime-local | email | file | hidden | image | month | number | password | radio | range | reset | search | submit | tel | text | time | url | week Specifies that its input element is a one-line plain-text edit control for the input element's value
type command | radio | checkbox Specifies that its command element is a command with an associated action, represents a selection of one item from a list of items, or represents a state or option that can be toggled
type MIME type MIME type of the content
type toolbar | context Kind of menu being declared
usemap hash-name reference Hash-name reference to a map element with which to associate the image
value string Specifies a value
value string Specifies a value for this input element
value integer Ordinal value of the list item. Permitted only if the li element is a child of an ol element
value float Measured value shown by meter
value string Value of the parameter
width non-negative integer Width of the canvas in CSS pixels
wrap hard | soft Instructs the UA to insert line breaks, or no line breaks, into the submitted value of the textarea, such that each line has no more characters than the value specified by the cols attribute
 
Common:
Name: Value: Description:
accesskey key label list Key label or list of key labels with which to associate the element; each key label represents a keyboard shortcut which UAs can use to activate the element or give focus to the element
class tokens Name of a classification, or list of names of classifications, to which the element belongs
contenteditable true | false | empty Specifies whether the contents of the element are editable - HTML5
contextmenu IDREF Identifies a menu with which to associate the element as a context menu - HTML5
dir ltr | rtl Specifies the element's text directionality
draggable true | false Specifies whether the element is draggable - HTML5
hidden hidden | empty Specifies that the element represents an element that is not yet, or is no longer, relevant - HTML5
id ID Unique identifier for the element
lang language tag Specifies the primary language for the contents of the element and for any of the element's attributes that contain text
onabort string Handles the event when the download is aborted by the user
onblur string Handles the event losing focus
oncanplay string Handles the event when the user agent can resume playback of the media data, but estimates that if playback were to be started now, the media resource could not be rendered at the current playback rate up to its end without having to stop for further buffering of content
oncanplaythrough string Handles the event when the user agent estimates that if playback were to be started now, the media resource could be rendered at the current playback rate all the way to its end without having to stop for further buffering
onchange string Handles the event when the user commits a value change
onclick string Handles the event when the user clicks the mouse
oncontextmenu string Handles the event when the user requests their context menu
ondblclick string Handles the event when the user double-clicks the mouse
ondrag string Handles the event when the drag is in progress
ondragend string Handles the event when the drag is completed
ondragenter string Handles the event when the drag object enters an area
ondragleave string Handles the event when the drag object leaves an area
ondragover string Handles the event when the drag object is over an area
ondragstart string Handles the event when the drag is initiated
ondrop string Handles the event when the drag object is released
ondurationchange string Handles the event when the duration attribute has just been updated
onemptied string Handles the event when a media element whose networkState was previously not in the NETWORK_EMPTY state has just switched to that state (either because of a fatal error during load that's about to be reported, or because the load() method was invoked while the resource selection algorithm was already running)
onended string Handles the event when playback has stopped because the end of the media resource was reached
onerror string Handles the event when network and script errors occur
onfocus string Handles the event gaining focus
onformchange string Handles the event when the user commits a value change to a control on the form
onforminput string Handles the event when the user changes the value of a control on the form
oninput string Handles the event when the user changes the value
oninvalid string Handles the event during form validation if they do not satisfy their constraints
onkeydown string Handles the event when the key is down
onkeypress string Handles the event when the key is pressed
onkeyup string Handles the event when the key is up
onload string Handles the event when the document has finished loading; fired at an element containing a resource (e.g. img, embed) when its resource has finished loading
onloadeddata string Handles the event when the user agent can render the media data at the current playback position for the first time
onloadedmetadata string Handles the event when the user agent has just determined the duration and dimensions of the media resource
onloadstart string Handles the event when the user agent begins looking for media data, as part of the resource selection algorithm
onmousedown string Handles the event when the user presses the mouse button
onmousemove string Handles the event when the user moves the mouse
onmouseout string Handles the event when user moves the mouse icon outside the object
onmouseover string Handles the event when the user moves the mouse icon over the object
onmouseup string Handles the event when the user releases the mouse button
onmousewheel string Handles the event when the user moves the mouse wheel
onpause string Handles the event when playback has been paused. Fired after the pause method has returned
onplay string Handles the event when playback has begun. Fired after the play() method has returned
onplaying string Handles the event when playback has started
onprogress string Handles the event when the user agent is fetching media data
onratechange string Handles the event when either the defaultPlaybackRate or the playbackRate attribute has just been updated
onreadystatechange string Handles the event when it finishes parsing and again when all its subresources have finished loading
onscroll string Handles the event when it is scrolled
onseeked string Handles the event when the seeking IDL attribute changed to false
onseeking string Handles the event when the seeking IDL attribute changed to true and the seek operation is taking long enough that the user agent has time to fire the event
onselect string Handles the event when it is selected
onshow string Handles the event when it is shown as a context menu
onstalled string Handles the event when the user agent is trying to fetch media data, but data is unexpectedly not forthcoming
onsubmit string Handles the event when it is submitted
onsuspend string Handles the event when the user agent is intentionally not currently fetching media data, but does not have the entire media resource downloaded
ontimeupdate string Handles the event when the current playback position changed as part of normal playback or in an especially interesting way, for example discontinuously
onvolumechange string Handles the event when either the volume attribute or the muted attribute has changed. Fired after the relevant attribute's setter has returned
onwaiting string Handles the event when playback has stopped because the next frame is not available, but the user agent expects that frame to become available in due course
spellcheck true | false | empty Specifies whether the element represents an element whose contents are subject to spell checking and grammar checking - HTML5
style string Specifies zero or more CSS declarations that apply to the element
tabindex integer Specifies whether the element represents an element that is is focusable (that is, an element which is part of the sequence of focusable elements in the document), and the relative order of the element in the sequence of focusable elements in the document
title normal character data Advisory information associated with the element

References

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W3C HTML 4.01 Specification

W3C HTML 4.01 Specification List

W3C HTML5

W3C HTML5 List

W3C HTML: The Markup Language

W3C HTML: The Markup Language Common List

W3C HTML: The Markup Language Forms List