HTML <script> Tag
The HTML <script>
tag is used for declaring a script within your HTML document.
Many web pages use scripts (usually JavaScript) to provide extra functionality that cannot be accomplished with HTML alone. Any time a script is embedded into an HTML document, it must be enclosed within <script>
tags.
Syntax
The <script>
tag is written as <script>
</script>
with the script inserted between the start and end tags.
Like this:
Examples
Basic tag usage
Using the <noscript>
Tag
You can use the <noscript>
tag to provide content for user agents/browsers that don't support scripting.
Any content enclosed between the <noscript>
tags is only displayed on browsers that don't support scripting.
Attributes
Attributes can be added to an HTML element to provide more information about how the element should appear or behave.
The <script>
element accepts the following attributes.
Attribute | Description | ||||||
---|---|---|---|---|---|---|---|
src | Specifies a URI/URL of an external script. | ||||||
async | Specifies whether a script will executed asynchronously, as soon as it is available.
This is a boolean attribute. If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace (i.e. either Possible values:
|
||||||
defer | Specifies whether the script is executed after the page has finished parsing, or immediately. If the async attribute is not present but the defer attribute is present, then the script is executed when the page has finished parsing. If neither attribute is present, then the script is fetched and executed immediately, before the user agent continues parsing the page.
This is a boolean attribute. If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace (i.e. either Possible values:
|
||||||
type | Specifies the scripting language as a content-type (MIME type). | ||||||
charset | Defines the character encoding that the script uses. | ||||||
crossorigin | This attribute is a CORS settings attribute. CORS stands for Cross-Origin Resource Sharing. The purpose of the crossorigin attribute is to allow you to configure the CORS requests for the element's fetched data. The values for the crossorigin attribute are enumerated.
Possible values:
If this attribute is not specified, CORS is not used at all. An invalid keyword and an empty string will be handled as the |
Global Attributes
The following attributes are standard across all HTML elements. Therefore, you can use these attributes with the <script>
tag , as well as with all other HTML tags.
accesskey
autocapitalize
class
contenteditable
data-*
dir
draggable
hidden
id
inputmode
is
itemid
itemprop
itemref
itemscope
itemtype
lang
part
slot
spellcheck
style
tabindex
title
translate
For a full explanation of these attributes, see HTML 5 global attributes.
Event Handlers
Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.
onabort
onauxclick
onblur
oncancel
oncanplay
oncanplaythrough
onchange
onclick
onclose
oncontextmenu
oncopy
oncuechange
oncut
ondblclick
ondrag
ondragend
ondragenter
ondragexit
ondragleave
ondragover
ondragstart
ondrop
ondurationchange
onemptied
onended
onerror
onfocus
onformdata
oninput
oninvalid
onkeydown
onkeypress
onkeyup
onlanguagechange
onload
onloadeddata
onloadedmetadata
onloadstart
onmousedown
onmouseenter
onmouseleave
onmousemove
onmouseout
onmouseover
onmouseup
onpaste
onpause
onplay
onplaying
onprogress
onratechange
onreset
onresize
onscroll
onsecuritypolicyviolation
onseeked
onseeking
onselect
onslotchange
onstalled
onsubmit
onsuspend
ontimeupdate
ontoggle
onvolumechange
onwaiting
onwheel
Most event handler content attributes can be used on all HTML elements, but some event handlers have specific rules around when they can be used and which elements they are applicable to.
For more detail, see HTML event handler content attributes.