Clear the cache in JavaScript

Question

You can call window.location.reload(true) to reload the current page. It will ignore any cached items and retrieve new copies of the page, css, images, JavaScript, etc from the server. This doesn't clear the whole cache, but has the effect of clearing the cache for the page you are on.

However, your best strategy is to version the path or filename as mentioned in various other answers. In addition, see Revving Filenames: don’t use querystring for reasons not to use ?v=n as your versioning scheme.

You can't clear the cache with javascript. A common way is to append the revision number or last updated timestamp to the file, like this:

myscript.123.js

or

myscript.js?updated=1234567890

Try changing the JavaScript file's src? From this:

<script language="JavaScript" src="js/myscript.js"></script>

To this:

<script language="JavaScript" src="js/myscript.js?n=1"></script>

This method should force your browser to load a new copy of the JS file.

Other than caching every hour, or every week, you may cache according to file data.

Example (in PHP):

<script src="js/my_script.js?v=<?=md5_file('js/my_script.js')?>"></script>

or even use file modification time:

<script src="js/my_script.js?v=<?=filemtime('js/my_script.js')?>"></script>

You can also force the code to be reloaded every hour, like this, in PHP :

<?php
echo '<script language="JavaScript" src="js/myscript.js?token='.date('YmdH').'">';
?>

or

<script type="text/javascript" src="js/myscript.js?v=<?php echo date('YmdHis'); ?>"></script>