X
HOME HTML CSS JAVASCRIPT SQL PHP JQUERY ANGULAR BOOTSTRAP XML ASP.NET MORE...
REFERENCES | EXAMPLES | FORUM | ABOUT

HTML <script> defer Attribute

HTML script Tag Reference HTML <script> tag

Example

A script that will not run until after the page has loaded:

<script src="demo_defer.js" defer></script>

Try it Yourself »

Browser Support

Internet Explorer Firefox Opera Google Chrome Safari

The defer attribute is supported in all major browsers.

Note: The defer attribute is not supported in Opera 12 and earlier versions.


Definition and Usage

The defer attribute is a boolean attribute.

When present, it specifies that the script is executed when the page has finished parsing.

Note: The defer attribute is only for external scripts (should only be used if the src attribute is present).

Note: There are several ways an external script can be executed:

  • If async is present: The script is executed asynchronously with the rest of the page (the script will be executed while the page continues the parsing)
  • If async is not present and defer is present: The script is executed when the page has finished parsing
  • If neither async or defer is present: The script is fetched and executed immediately, before the browser continues parsing the page

Differences Between HTML 4.01 and HTML5

NONE.


Differences Between HTML and XHTML

In XHTML, attribute minimization is forbidden, and the defer attribute must be defined as <script defer="defer">.


Syntax

<script defer>


HTML script Tag Reference HTML <script> tag

Your suggestion:

Close [X]

Thank You For Helping Us!

Your message has been sent to W3Schools.

Close [X]
Search w3schools.com:

WEB HOSTING

UK Reseller Hosting

WEB BUILDING

Download XML Editor FREE Website BUILDER Free HTML5 Templates

SHARE THIS PAGE

facebook