When a user visit your website, they do things like click on text and images and given links, hover over things etc. These are examples of what JavaScript calls events.
We can write our event handlers in Javascript or vbscript and can specify these event handlers as a value of event tag attribute. The HTML 4.01 specification defines 19 event attributes as listed below −
<body> and <frameset> Level Events
There are only two attributes which can be used to trigger any javascript or vbscript code when there is any event occurs on document level.
| Attribute | Value | Description |
|---|---|---|
| onload | script | Script runs when a HTML document loads |
| onunload | script | Script runs when a HTML document unloads |
NOTE − Here script refer to any VBScript or JavaScript function or piece of code.
<form> Level Events
There are following six attributes which can be used to trigger any javascript or vbscript code when there is any event occurs on form level.
| Attribute | Value | Description |
|---|---|---|
| onchange | script | Script runs when the element changes |
| onsubmit | script | Script runs when the form is submitted |
| onreset | script | Script runs when the form is reset |
| onselect | script | Script runs when the element is selected |
| onblur | script | Script runs when the element loses focus |
| onfocus | script | Script runs when the element gets focus |
Keyboard Events
There are following three events which are generated by keyboard. These events are not valid in base, bdo, br, frame, frameset, head, html, iframe, meta, param, script, style, and title elements.
| Attribute | Value | Description |
|---|---|---|
| onkeydown | script | Script runs when key is pressed |
| onkeypress | script | Script runs when key is pressed and released |
| onkeyup | script | Script runs when key is released |
Other Events
There following other 7 events which are generated by mouse when it comes in contact of any HTML tag. These events are not valid in base, bdo, br, frame, frameset, head, html, iframe, meta, param, script, style, title elements.
| Attribute | Value | Description |
|---|---|---|
| onclick | script | Script runs when a mouse click |
| ondblclick | script | Script runs when a mouse double-click |
| onmousedown | script | Script runs when mouse button is pressed |
| onmousemove | script | Script runs when mouse pointer moves |
| onmouseout | script | Script runs when mouse pointer moves out of an element |
| onmouseover | script | Script runs when mouse pointer moves over an element |
| onmouseup | script | Script runs when mouse button is released |
The HTML 4.01 specification had defined 19 events but later HTML-5 has added many other events which we have listed down here −
Window Events Attributes
Following events have been introduced in older versions of HTML but all the tags marked with 
are part of HTML-5.
are part of HTML-5.| Events | HTML-5 | Description |
|---|---|---|
| onafterprint | | Triggers after a document is printed |
| onbeforeprint | | Triggers before a document is printed |
| onbeforeonload | | Triggers before a document loads |
| onerror | | Triggers when an error occurs |
| onhaschange | | Triggers when a document has changed |
| onload | Triggers when a document loads | |
| onmessage | | Triggers when a message is triggered |
| onoffline | | Triggers when a document goes offline |
| ononline | | Triggers when a document comes online |
| onpagehide | | Triggers when a window is hidden |
| onpageshow | | Triggers when a window becomes visible |
| onpopstate | | Triggers when a window's history changes |
| onredo | | Triggers when a document performs a redo |
| onresize | | Triggers when a window is resized |
| onstorage | | Triggers when a document loads |
| onundo | | Triggers when a document performs an undo |
| onunload | Triggers when a user leaves the document |
Form Events
Following tags have been introduced in older versions of HTML but all the tags marked with are part of HTML-5.
are part of HTML-5.| Events | HTML-5 | Description |
|---|---|---|
| onblur | Triggers when a window loses focus | |
| onchange | Triggers when an element changes | |
| oncontextmenu | | Triggers when a context menu is triggered |
| onfocus | Triggers when a window gets focus | |
| onformchange | | Triggers when a form changes |
| onforminput | | Triggers when a form gets user input |
| oninput | | Triggers when an element gets user input |
| oninvalid | | Triggers when an element is invalid |
| onreset | Triggers when a form is reset | |
| onselect | Triggers when an element is selected | |
| onsubmit | Triggers when a form is submitted |
Keyboard Events
| Events | HTML-5 | Description |
|---|---|---|
| onkeydown | Triggers when a key is pressed | |
| onkeypress | Triggers when a key is pressed and released | |
| onkeyup | Triggers when a key is released |
Mouse Events
Following tags have been introduced in older versions of HTML but all the tags marked with are part of HTML-5.
are part of HTML-5.| Events | HTML-5 | Description |
|---|---|---|
| onclick | Triggers on a mouse click | |
| ondblclick | Triggers on a mouse double-click | |
| ondrag | | Triggers when an element is dragged |
| ondragend | | Triggers at the end of a drag operation |
| ondragenter | | Triggers when an element has been dragged to a valid drop target |
| ondragleave | | Triggers when an element leaves a valid drop target |
| ondragover | | Triggers when an element is being dragged over a valid drop target |
| ondragstart | | Triggers at the start of a drag operation |
| ondrop | | Triggers when a dragged element is being dropped |
| onmousedown | Triggers when a mouse button is pressed | |
| onmousemove | Triggers when the mouse pointer moves | |
| onmouseout | Triggers when the mouse pointer moves out of an element | |
| onmouseover | Triggers when the mouse pointer moves over an element | |
| onmouseup | Triggers when a mouse button is released | |
| onmousewheel | | Triggers when the mouse wheel is being rotated |
| onscroll | | Triggers when an element's scrollbar is being scrolled |
Media Events
Following tags have been introduced in older versions of HTML but all the tags marked with are part of HTML-5.
are part of HTML-5.| Events | HTML-5 | Description |
|---|---|---|
| onabort | Triggers on an abort event | |
| oncanplay | | Triggers when a media can start play, but might has to stop for buffering |
| oncanplaythrough | | Triggers when a media can be played to the end, without stopping for buffering |
| ondurationchange | | Triggers when the length of a media is changed |
| onemptied | | Triggers when a media resource element suddenly becomes empty. |
| onended | | Triggers when a media has reached the end |
| onerror | | Triggers when an error occurs |
| onloadeddata | | Triggers when media data is loaded |
| onloadedmetadata | | Triggers when the duration and other media data of a media element is loaded |
| onloadstart | | Triggers when the browser starts loading the media data |
| onpause | | Triggers when media data is paused |
| onplay | | Triggers when media data is going to start playing |
| onplaying | | Triggers when media data has started playing |
| onprogress | | Triggers when the browser is fetching the media data |
| onratechange | | Triggers when the playing rate of media data has changed |
| onreadystatechange | | Triggers when the ready-state changes |
| onseeked | | Triggers when the seeking attribute of a media element is no longer true, and the seeking has ended |
| onseeking | | Triggers when the seeking attribute of a media element is true, and the seeking has begun |
| onstalled | | Triggers when there is an error in fetching media data |
| onsuspend | | Triggers when the browser has been fetching media data, but stopped before the entire media file was fetched |
| ontimeupdate | | Triggers when media changes its playing position |
| onvolumechange | | Triggers when a media changes the volume, also when volume is set to "mute" |
| onwaiting | | Triggers when media has stopped playing, but is expected to resume |
