async attribute | async property
Provides control of when a script executes while a document loads. Setting a script to run asynchronously can improve performance by unblocking the rest of the document. When async = false, it can preserve execution order to ensure dependent scripts are run in order.
This property is read/write.
 |
Syntax
| HTML |
|---|
<element async="ptr" ... > |
| JavaScript |
|---|
object.async = ptr ptr = object.async |
Property values
Type: boolean
When true, the script will execute asynchronously, otherwise script is executed as page loads.
Remarks
Starting with Windows 8.1, dynamically added script elements load asynchronously for Windows Runtime apps using JavaScript. To learn more, see API Changes for Windows 8.1.
See also
Show: