HTML 5 Event Handler Content Attributes

When your users visit your website, they do things like click on things, hover over things etc. These are examples of what JavaScript calls events. Within your HTML, you can respond to an event using an event handler content attribute.

You can attach an event handler content attribute to the HTML element for which you want to respond to when a specific event occurs. For example, you could attach the onmouseover event handler content attribute to a button and specify some JavaScript to run whenever the user hovers over the button.

Event handler content attributes are often referred to simply as "event handlers". Below are the event handlers available in HTML.

Event Handlers for All HTML Elements & document & window Objects

The following table lists the event handlers supported by all HTML elements, as both event handler content attributes and event handler IDL attributes; and supported by all Document and Window objects, as event handler IDL attributes.

Attribute Description
onabort Invoked when an event has been aborted. For example, the browser stops fetching media data before it is completely downloaded.
onauxclick auxclick event handler.
oncancel cancel event handler.
oncanplay Invoked when the browser/user agent can start playing media, but hasn't yet, due to buffering. In other words, if playback were to begin now, it wouldn't play right to the end (due to the current playback rate) - it would need to pause during playback in order to load the rest of the media.
oncanplaythrough The browser/user agent estimates that if playback were to begin 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 User has changed the object, then attempts to leave that field (i.e. clicks elsewhere).
onclick Invoked when the user clicked on the object.
onclose close event handler.
oncontextmenu Invoked when a context menu has been triggered.
oncuechange cuechange event handler.
ondblclick Invoked when the user clicked twice on the object.
ondrag Invoked when an element is being dragged.
ondragend Invoked when an element has stopped being dragged.
ondragenter Invoked when an element has been dragged to a drop target.
ondragexit dragexit event handler.
ondragleave Invoked when an element leaves a valid drop target.
ondragover Invoked when an element is being dragged over a valid drop target.
ondragstart Invoked when a drag operation has started.
ondrop Invoked when an element is being dropped.
ondurationchange Invoked when the length of the media is changed (i.e. the duration attribute has just been updated).
onemptied Invoked when a media resource element suddenly becomes empty (for example, due to a network error).
onended Invoked when the media has reached the end.
onformdata formdata event handler.
oninput input event handler.
oninvalid invalid event handler.
onkeydown Invoked when a key was pressed over an element.
onkeypress Invoked when a key was pressed over an element then released.
onkeyup Invoked when a key was released over an element.
onloadeddata Invoked when the browser/user agent can render the media data at the current playback position for the first time.
onloadedmetadata Invoked when the browser/user agent has just determined the duration and dimensions of the media resource.
onloadstart Invoked when the browser/user agent has started loading the media resource.
onmousedown The cursor moved over the object and mouse/pointing device was pressed down.
onmouseenter mouseenter event handler.
onmouseleave mouseleave event handler.
onmousemove The cursor moved while hovering over an object.
onmouseout The cursor moved off the object
onmouseover The cursor moved over the object (i.e. user hovers the mouse over the object).
onmouseup The mouse/pointing device was released after being pressed down.
onpause Invoked when the media resource has been paused.
onplay Invoked when the media resource starts playback.
onplaying Playback has begun.
onprogress The browser/user agent is fetching media data the.
onratechange Invoked when the playback rate has changed (i.e. either the defaultPlaybackRate or the playbackRate has just been updated).
onreset reset event handler.
onsecuritypolicyviolation securitypolicyviolation event handler.
onseeked Invoked when the seeking IDL attribute changed to false (i.e. the seeking attribute is no longer true)
onseeking Invoked 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 Invoked when some or all of the contents of an object is selected. For example, the user selected some text within a text field.
onslotchange slotchange event handler.
onstalled Invoked when the browser/user agent is trying to fetch media data but the data has stalled (i.e. the data has stopped coming).
onsubmit User submitted a form.
onsuspend The browser/user agent is (intentionally) not currently fetching media data, but has not yet downloaded the entire media resource (i.e. it has suspended the download).
ontimeupdate Invoked when the media's current playback position changed.
ontoggle toggle event handler.
onvolumechange Invoked when either the volume attribute or the muted attribute has changed.
onwaiting The next frame of the media is not yet available (but the browser/user agent expects it to become available).
onwebkitanimationend webkitanimationend event handler.
onwebkitanimationiteration webkitAnimationIteration event handler.
onwebkitanimationstart webkitAnimationStart event handler.
onwebkittransitionend webkitTransitionEnd event handler.
onwheel wheel event handler.

The following table lists the event handlers (and their corresponding event handler event types) supported by all HTML elements other than body and frameset elements, as both event handler content attributes and event handler IDL attributes; supported by all Document objects, as event handler IDL attributes; and supported by all Window objects, as event handler IDL attributes on the Window objects themselves, and with corresponding event handler content attributes and event handler IDL attributes exposed on all body and frameset elements that are owned by that Window object's associated Document.

Attribute Description
onblur User has left the focus of the element.
onerror Invoked when an error occurs while the Window object is being loaded. Also handler for script error notifications.
onfocus Invoked when the focus is on the element.
onload The element has loaded.
onresize The viewport has been resized.
onscroll scroll event handler. Invoked when the element's scrollbar is being scrolled.

The following table lists the event handlers supported by Window objects, as event handler IDL attributes on the Window objects themselves, and with corresponding event handler content attributes and event handler IDL attributes exposed on all body and frameset elements that are owned by that Window object's associated Document.

Attribute Description
onafterprint afterprint event handler
onbeforeprint beforeprint event handler
onbeforeunload beforeunload event handler
onhashchange hashchange event handler. The hashchange event is fired when navigating to a session history entry whose URL differs from that of the previous one only in the fragment identifier.
onlanguagechange languagechange event handler.
onmessage message event handler.
onmessageerror messageerror event handler.
onoffline offline event handler.
ononline online event handler.
onpagehide pagehide event handler. The pagehide event is fired when traversing from a session history entry.
onpageshow pageshow event handler. The pageshow event is fired when traversing to a session history entry.
onpopstate popstate event handler. The popstate event is fired when navigating to a session history entry that represents a state object.
onrejectionhandled rejectionhandled event handler.
onstorage storage event handler.
onunhandledrejection unhandledrejection event handler.
onunload unload event handler.

The following are the event handlers supported by all HTML elements, as both event handler content attributes and event handler IDL attributes; and supported by all Document objects, as event handler IDL attributes:

Attribute Description
oncut cut event handler.
oncopy copy event handler.
onpaste paste event handler.

The following event handler is supported on Document objects as an event handler IDL attribute.

Attribute Description
onreadystatechange readystatechange event handler.