Edit before output (render) site content WordPress and modify content (Buffer) | Edit site content

functions.php

<?php
/*
* WordPress modifying the output before render or edit site content.
*
* Apply find and replace rules
* or you can make any modification before content going on to show users.
*
* It's simple, just paste this code on your Plugin/Theme functions.
*/

function modify_buffer_ob_call( $buffer ) { 
	// Here you can change the HTML content
	return $buffer;
}

function modify_buffer() {
	ob_start();
	ob_start( 'modify_buffer_ob_call' );
}

add_action( 'template_redirect', 'modify_buffer' );