How to prevent Browser cache for php site

[admin]

Here, if you want to control it through HTML: do like below Option 1:

<meta http-equiv="expires" content="Sun, 01 Jan 2021 00:00:00 GMT"/>
<meta http-equiv="pragma" content="no-cache" />
 
And if you want to control it through PHP: do it like below Option 2:

header('Expires: Sun, 01 Jan 2021 00:00:00 GMT');
header('Cache-Control: no-store, no-cache, must-revalidate');
header('Cache-Control: post-check=0, pre-check=0', FALSE);
header('Pragma: no-cache');

AND Option 2 IS ALWAYS BETTER in order to avoid proxy based caching issue.