Obfuscate links in WordPress (for SEO purpose)

I ended up making my own system that allows me to obfuscate any link easily.

Add the following code to your child theme's functions.php file, then just add the class "obfuscate" to any element to obfuscate its link by replacing it with a element with no readable link.

Also be sure to edit styles above, or delet them and style the "akn-obf-link" class in your own CSS file, so that it looks like a link to the visitor.

<?php

/**************************************************************************************
|* Links obfuscation - add class "obfuscate" to any <a> element to obfuscate its link *|
**************************************************************************************/

// Add this code to your child theme's functions.php file, then just add the class "obfuscate" to any <a> element to obfuscate its link by replacing it with a <span> element with no readable link.
// The obfuscated elements inherits the original <a> element's classes, along with a "akn-obf-link" class, so you might need to add CSS to style the "akn-obf-link" class so that it looks like a link to the visitor, maybe at least to add a cursor:pointer.
// On right click, the obfuscated link will be wrapped with a proper <a> element with the "akn-deobf-link" for a brief moment, so that a proper context menu appears, you can remove that behaviour by setting the "deobfuscate_on_right_click" option to false in the code bellow.

// Edit 2022-04-05 - modified regex to allow for html elements and new lines into the <a> element, modified callback so the obfuscated element inherits the original link's classes, modified JS to add mousewheel click and right click options.

// Edit 2023-01-26 - greatly improved regex thanks to @MadMaxInfinity on Stack Overflow, it now both allows more matches in different scenarios and returns less false positives matches, more infos on his answer here: https://stackoverflow.com/a/75234749/2498324

// Edit 2023-02-08 - improved class regex thanks to @MadMaxInfinity on Stack Overflow again.

add_action('wp_loaded', 'buffer_start');
function buffer_start() {
    ob_start('akn_ofbuscate_buffer');
}
add_action('shutdown', 'buffer_end');
function buffer_end() {
    ob_end_flush();
}
function akn_ofbuscate_buffer($buffer) {
    $result = preg_replace_callback('#<a[^>]+((?<=s)href=("|')([^"']*)('|")[^>]+(?<=s)class=("|')[^'"]*(?<!w|-)obfuscate(?!w|-)[^'"]*("|')|(?<=s)class=("|')[^'"]*(?<!w|-)obfuscate(?!w|-)[^'"]*("|')[^>]+(?<=s)href=("|')([^"']*)('|"))[^>]*>(.*)</a>#miUs', function($matches) {
        preg_match('#<a[^>]+(?<=s)class=["|\']([^\'"]+)["|\']#imUs',$matches[0],$matches_classes);
        $classes = trim(preg_replace('/s+/',' ',str_replace('obfuscate','',$matches_classes[1])));
        return '<span class="akn-obf-link'.($classes?' '.$classes:'').'" data-o="'.base64_encode($matches[3]?:$matches[10]).'" data-b="'.((strpos(strtolower($matches[0]),'_blank')!==false)?'1':'0').'">'.$matches[12].'</span>';
    }, $buffer);
    return $result;
}
add_action('wp_footer', 'akn_ofbuscate_footer_js');
function akn_ofbuscate_footer_js() {
    ?>
        <script>
            jQuery(document).ready(function($) {
                // options you can change
                var deobfuscate_on_right_click = true;
                // function to open link on click
                function akn_ofbuscate_clicked($el,force_blank) {
                    if (typeof(force_blank)=='undefined')
                        var force_blank = false;
                    var link = atob($el.data('o'));
                    var _blank = $el.data('b');
                    if (_blank || force_blank)
                        window.open(link);
                    else
                        location.href = link;
                }
                // trigger link opening on click
                $(document).on('click','.akn-obf-link',function() {
                    var $el = $(this);
                    if (!$el.closest('.akn-deobf-link').length)
                        akn_ofbuscate_clicked($el);
                });
                // trigger link openin in new tab on mousewheel click
                $(document).on('mousedown','.akn-obf-link',function(e) {
                    if (e.which==2) {
                        var $el = $(this);
                        if (!$el.closest('.akn-deobf-link').length) {
                            akn_ofbuscate_clicked($el,true);
                            return true;
                        }
                    }
                });
                // deobfuscate link on right click so the context menu is a legit menu with link options
                $(document).on('contextmenu','.akn-obf-link',function(e) {
                    if (deobfuscate_on_right_click) {
                        var $el = $(this);
                        if (!$el.closest('.akn-deobf-link').length) {
                            e.stopPropagation();
                            var link = atob($el.data('o'));
                            var _blank = $el.data('b');
                            $el.wrap('<a class="akn-deobf-link" href="'+link+'"'+(_blank?' target="_BLANK"':'')+'></a>').parent().trigger('contextmenu');
                            setTimeout(function() {
                                $el.unwrap();
                            },10);
                        }
                    }
                });
            });
        </script>
    <?php
}

I'm also sharing the code on this Pastebin: https://pastebin.com/cXEBSVFn

Consider checking the link just in case I updated the code on it and forgot to update it here