Make jQuery :contains Case-Insensitive

contains.js

// jquery > 1.8
$.expr[":"].contains = $.expr.createPseudo(function(arg) {
    return function( elem ) {
        return $(elem).text().toUpperCase().indexOf(arg.toUpperCase()) >= 0;
    };
});

//---uso
$("div:contains('John')")


//---html
<div>john</div>
<div>John</div>
<div>hey hey JOHN hey hey</div>