Removing blank spaces from scripts to reducing page load time

I write one php code what totaly filter all html elements but is integrated in main index.php on the root. That made rendering a little faster but you also can do CDN for all your images and media. That will speedup your page a mutch better. I normaly point /wp-content/uploads/ to subdomain and my WP get all media from that subdomain what made WP 20 times faster.

UPDATE

I made one great regex what can work inside buffer. Copy/Paste this script in your theme functions.php and see magic.

NOTE: If your source contain bad javascript or css what’s not follow
rules, this may broke website. But I use it on arround 100 templates,
I never experience some issue. Work nice With Elementor and WC Builder

/* ----------------------------------------------------------------------------

   W3C Fix and HTML minifier by Ivijan-Stefan Stipic <[email protected]>

---------------------------------------------------------------------------- */
add_action('wp_loaded', 'atm_output_buffer_start');
add_action('shutdown', 'atm_output_buffer_end');

function atm_output_buffer_start() { 
    ob_start("atm_output_callback");
}

function atm_output_buffer_end() { 
    ob_get_clean();
}

function atm_output_callback($buffer) {
    if(!is_admin() && !(defined('DOING_AJAX') && DOING_AJAX))
    {
        // Remove type from javascript and CSS
        $buffer = preg_replace( "%[ ]type=[\'\"]text\/(javascript|css)[\'\"]%", '', $buffer );
        // Add alt attribute to images where not exists
        $buffer = preg_replace( '%(<img(?!.*?alt=([\'"]).*?\2)[^>]*?)(/?>)%', '$1 alt="" $3', $buffer );
        $buffer = preg_replace( '%\s+alt="%', ' alt="', $buffer );
        // clear HEAD
        $buffer = preg_replace_callback('/(?=<head(.*?)>)(.*?)(?<=<\/head>)/s',
        function($matches) {
            return preg_replace(array(
                '/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s', // delete HTML comments
                /* Fix HTML */
                '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
                '/[^\S ]+\</s',  // strip whitespaces before tags, except space
                '/\>\s+\</',    // strip whitespaces between tags
            ), array(
                '',
                /* Fix HTML */
                '>',  // strip whitespaces after tags, except space
                '<',  // strip whitespaces before tags, except space
                '><',   // strip whitespaces between tags
            ), $matches[2]);
        }, $buffer);
        // clear BODY
        $buffer = preg_replace_callback('/(?=<body(.*?)>)(.*?)(?<=<\/body>)/s',
        function($matches) {
            return preg_replace(array(
                '/<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->).)*-->/s', // delete HTML comments
                /* Fix HTML */
                '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
                '/[^\S ]+\</s',  // strip whitespaces before tags, except space
                '/\>\s+\</',    // strip whitespaces between tags
            ), array(
                '', // delete HTML comments
                /* Fix HTML */
                '>',  // strip whitespaces after tags, except space
                '<',  // strip whitespaces before tags, except space
                '> <',   // strip whitespaces between tags
            ), $matches[2]);
        }, $buffer);
        $buffer = preg_replace_callback('/(?=<script(.*?)>)(.*?)(?<=<\/script>)/s',
        function($matches) {
            return preg_replace(array(
                '@\/\*(.*?)\*\/@s', // delete JavaScript comments
                '@((^|\t|\s|\r)\/{2,}.+?(\n|$))@s', // delete JavaScript comments
                '@(\}(\n|\s+)else(\n|\s+)\{)@s', // fix "else" statemant
                '@((\)\{)|(\)(\n|\s+)\{))@s', // fix brackets position
                //'@(\}\)(\t+|\s+|\n+))@s', // fix closed functions
                '@(\}(\n+|\t+|\s+)else\sif(\s+|)\()@s', // fix "else if"
                '@(if|for|while|switch|function)\(@s', // fix "if, for, while, switch, function"
                '@\s+(\={1,3}|\:)\s+@s', // fix " = and : "
                '@\$\((.*?)\)@s', // fix $(  )
                '@(if|while)\s\((.*?)\)\s\{@s', // fix "if|while ( ) {"
                '@function\s\(\s+\)\s{@s', // fix "function ( ) {"
                '@(\n{2,})@s', // fix multi new lines
                '@([\r\n\s\t]+)(,)@s', // Fix comma
                '@([\r\n\s\t]+)?([;,{}()]+)([\r\n\s\t]+)?@', // Put all inline
            ), array(
                "\n", // delete JavaScript comments
                "\n", // delete JavaScript comments
                '}else{', // fix "else" statemant
                '){', // fix brackets position
                //"});\n", // fix closed functions
                '}else if(', // fix "else if"
                "$1(",  // fix "if, for, while, switch, function"
                " $1 ", // fix " = and : "
                '$'."($1)", // fix $(  )
                "$1 ($2) {", // fix "if|while ( ) {"
                'function(){', // fix "function ( ) {"
                "\n", // fix multi new lines
                ',', // fix comma
                "$2", // Put all inline
            ), $matches[2]);
        }, $buffer);
        // Clear CSS
        $buffer = preg_replace_callback('/(?=<style(.*?)>)(.*?)(?<=<\/style>)/s',
        function($matches) {
            return preg_replace(array(
                '/([.#]?)([a-zA-Z0-9,_-]|\)|\])([\s|\t|\n|\r]+)?{([\s|\t|\n|\r]+)(.*?)([\s|\t|\n|\r]+)}([\s|\t|\n|\r]+)/s', // Clear brackets and whitespaces
                '/([0-9a-zA-Z]+)([;,])([\s|\t|\n|\r]+)?/s', // Let's fix ,;
                '@([\r\n\s\t]+)?([;:,{}()]+)([\r\n\s\t]+)?@', // Put all inline
            ), array(
                '$1$2{$5} ', // Clear brackets and whitespaces
                '$1$2', // Let's fix ,;
                "$2", // Put all inline
            ), $matches[2]);
        }, $buffer);

        // Clean between HEAD and BODY
        $buffer = preg_replace( "%</head>([\s\t\n\r]+)<body%", '</head><body', $buffer );
        // Clean between BODY and HTML
        $buffer = preg_replace( "%</body>([\s\t\n\r]+)</html>%", '</body></html>', $buffer );
        // Clean between HTML and HEAD
        $buffer = preg_replace( "%<html(.*?)>([\s\t\n\r]+)<head%", '<html$1><head', $buffer );
    }

    return $buffer;
}

For CDN read THIS article.